Seed Master 2

INSTRUCTION MANUAL FOR THE

SeedMaster 2Crystallization Transmitter and Automatic Seeding

Device

Document/Revision No. SeedMaster 2: Rev. 1/02 Effective: May 15, 2007.

PROCESS CONTROL KFT. PROFICON Industrial Controls Ltd.Postal address: Postal address:1091 BUDAPEST 1025 BUDAPESTHaller u. 88. Mandula u. 24.HUNGARY HUNGARYE-mail: [email protected] E-mail: [email protected]

mailto:[email protected]

CONTENTS

1 INTRODUCTION......................................................................................................................................... 4

2 SUGAR CRYSTALLIZATION IN BRIEF ................................................................................................ 6

2.1 THE LAST STEP: CRYSTALLIZATION.......................................................................................................... 62.2 SUPERSATURATION: THE DRIVING FORCE OF CRYSTALLIZATION.............................................................. 62.3 SEEDING METHODS .................................................................................................................................. 62.4 CRYSTAL CONTENT.................................................................................................................................. 92.5 PRODUCT QUALITY AND SUPERSATURATION............................................................................................ 92.6 COST OF PRODUCTION AND THE MAJOR PARAMETERS............................................................................ 102.7 COMMON INSTRUMENTS IN USE FOR CRYSTALLIZATION CONTROL......................................................... 112.8 MOUNTING THE K-PATENTS REFRACTOMETER ................................................................................... 12

3 THE SEEDMASTER 2 CRYSTALLIZATION TRANSMITTER AND SEEDING DEVICE........... 14

3.1 SEEDMASTER 2 DESCRIPTION ................................................................................................................ 143.2 SEEDMASTER 2: A FRONT-END DEVICE .................................................................................................. 143.3 PRINCIPLE OF OPERATION...................................................................................................................... 153.4 CALCULATED DATA ............................................................................................................................... 163.5 ON-LINE DATA INPUTS ........................................................................................................................... 17

3.5.1 Receiving syrup concentration data from the K-PATENTS refractometer(s) ...................................... 173.5.2 Receiving temperature data ................................................................................................................. 183.5.3 Selecting the “THIRD INPUT” transmitter ......................................................................................... 183.5.4 Using laboratory data instead of “THIRD INPUT”............................................................................ 183.5.5 Optional data input .............................................................................................................................. 18

3.6 DIGITAL INPUTS ..................................................................................................................................... 183.6.1 “STRIKE ACTIVE” input DIN1........................................................................................................... 183.6.2 “SEEDED” input DIN2 ....................................................................................................................... 193.6.3 “CHANGE FEED SYRUP” input DIN3 .............................................................................................. 19

3.7 DATA OUTPUTS ...................................................................................................................................... 193.7.1 Data available for transmission ........................................................................................................... 193.7.2 Standard current outputs...................................................................................................................... 20

3.8 DIGITAL (ON / OFF) OUTPUTS............................................................................................................... 203.8.1 “SEED WARNING” output DO1......................................................................................................... 203.8.2 “SEEDING” output DO2..................................................................................................................... 20

3.9 THE MAN-MACHINE INTERFACE ............................................................................................................. 20

4 TECHNICAL DATA, MOUNTING AND ELECTRICAL CONNECTIONS ...................................... 22

4.1 SPECIFICATIONS..................................................................................................................................... 224.2 ELECTRICAL CONNECTIONS ................................................................................................................... 24

4.2.1 Power supply........................................................................................................................................ 244.2.2 Process inputs and outputs................................................................................................................... 254.2.3 Digital communication......................................................................................................................... 254.2.4 I / O wirings ......................................................................................................................................... 26

4.3 CONSTRUCTION DETAILS ....................................................................................................................... 28

5 SEEDMASTER 2 FEATURES IN BRIEF ............................................................................................... 31

5.1 SEEDMASTER 2: OPERATOR STATION FEATURES ............................................................................ 315.1.1 CONFIGURE ....................................................................................................................................... 315.1.2 SET UP................................................................................................................................................. 315.1.3 DISPLAY .............................................................................................................................................. 315.1.4 MANUAL OPERATIONS ..................................................................................................................... 31

5.2 SEEDMASTER 2: TRANSMITTER FEATURES ....................................................................................... 325.2.1 Analog output ....................................................................................................................................... 325.2.2 Digital data communication................................................................................................................. 32

5.3 SEEDMASTER 2: SEEDING FEATURES ................................................................................................. 325.3.1 Seeding based on DIGITAL INPUT DIN2 ........................................................................................... 335.3.2 Seeding on a command from a PCS using digital communication....................................................... 335.3.3 MANUAL seeding................................................................................................................................. 335.3.4 AUTOMATIC seeding based on SUPERSATURATION ...................................................................... 335.3.5 AUTOMATIC seeding based on DENSITY .......................................................................................... 33

6 START UP AND USE............................................................................................................................. 34

6.1 START UP ............................................................................................................................................... 346.2 DEFAULT SETTINGS................................................................................................................................ 346.3 DEVICE CONFIGURATION ....................................................................................................................... 356.4 BASIC KEY OPERATIONS......................................................................................................................... 35

7 CONFIGURE SEEDMASTER 2 ....................................................................................................... 37

7.1 START CONFIGURATION ......................................................................................................................... 377.2 ORGANIZING SEEDMASTER 2 INPUT / OUTPUT TRAFFIC ........................................................................ 377.3 CONFIGURING THE STRIKE ACTIVE SIGNAL....................................................................................... 417.4 THIRD INPUT...................................................................................................................................... 43

7.4.1 Third input: MASSECUITE DENSITY or MASSECUITE SOLIDS CONTENT ................................... 437.4.2 Third input: MOTOR CONSUMPTION.............................................................................................. 457.4.3 Third input: CRYSTAL CONTENT (laboratory) .................................................................................. 48

7.5 SEEDING.............................................................................................................................................. 507.6 ACTIVE INSTRUMENT...................................................................................................................... 517.7 PASSWORD......................................................................................................................................... 517.8 COMMUNICATION............................................................................................................................ 52

7.8.1 Using the serial communication (COMX) ports................................................................................... 527.8.2 Using the ETHERNET.......................................................................................................................... 537.8.3 Organizing the two-way data transfer.................................................................................................. 54

8 SET UP SEEDMASTER 2 ......................................................................................................................... 55

8.1 SET UP DISPLAY .................................................................................................................................. 558.2 SET UP INPUTS..................................................................................................................................... 57

8.2.1 Data types and specifications............................................................................................................. 5278.2.2 Handling the use of several feed syrups with different purities............................................................ 608.2.3 Set up syrup parameters....................................................................................................................... 61

8.3 SET UP DIGITAL I / O ........................................................................................................................... 628.4 SET UP ANALOG OUTPUT.................................................................................................................. 64

9 MANUAL SEEDING.................................................................................................................................. 65

10 DISPLAY ............................................................................................................................................. 66

10.1 MAIN DISPLAY .............................................................................................................................. 6610.2 TREND ............................................................................................................................................. 6810.3 STRIKE HISTORY........................................................................................................................... 7010.4 STANDARD DISPLAY ................................................................................................................... 7010.5 SYSTEM INFORMATION .............................................................................................................. 7110.6 TEST DATA ..................................................................................................................................... 72

11 COMMUNICATION................................................................................................................................ 76

11.1 ETHERNET COMMUNICATION................................................................................................... 76Data transmission using the Ethernet ........................................................................................................... 76Cable requirements and connection ............................................................................................................ 76Cable specification........................................................................................................................................ 76Connecting the Ethernet cable ...................................................................................................................... 76Connection settings ....................................................................................................................................... 77Testing the connection .................................................................................................................................. 77Troubleshooting ............................................................................................................................................ 78MODBUS TCP / IP as implemented in SeedMaster 2 .................................................................................. 78

11.2 MODBUS PROTOCOL USING ONE OF THE COMX PORTS ................................................................... 8111.3 DATA TYPES USED IN THE MODBUS REGISTERS ............................................................................... 8411.4 REGISTER SET .................................................................................................................................... 85

12 APPENDIX 1 : PROCEDURE TO EVALUATE THE “M”, “B” AND “C” COEFFICIENTS OF THE WIKLUND-VAVRINECZ SATURATION FUNCTION. ..................................................................... 89

12.1 INTRODUCING THE SOLUBILITY COEFFICIENT............................................................................................. 8912.2 DETERMINING THE LOCAL SYRUP PARAMETERS................................................................................. 90

12.2.1 Sample preparation for the saturation test......................................................................................... 90

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12.2.2 Saturation test .................................................................................................................................... 9112.2.3 Evaluation .......................................................................................................................................... 91

APPENDIX 2 : CONFIGURATION DATA SHEETS……………………………………………94

SUBJECT INDEX……………………………………………………………………………………………..100

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INTRODUCTION

Sugar manufacturing dates back more than one and a half century. World sugar production in year 2000 reached 150 million tons, which probably represents the largest amount of a product produced in crystalline form.Due to the long history of sugar manufacturing the sugar industry is regarded as a mature one, where no exciting new developments can be expected. It has long traditions based on the work of skilled people, who acquired their skill in controlling the various parts of the technology often during their lifetime. However, times are changing. The fierce competition in the industry and in the market forces even industries with long traditions to make effective use of the advanced methods of production in order to survive. It became evident that besides better machinery and equipment in the technology, the use of new types of equipment and know-how is a must for the plants if they wish to be competitive.Some of the new equipment comes in the form of new instruments and computer-based automatic control systems,never heard of before, but there are substantial changes in the required know-how, too. In addition to the usual chemical- and mechanical-engineering background experience in instrumentation, automatic process control and in the use of computers and informatics became vital. Conclusion: there are substantial changes even in a “mature” industry.

Crystallization is a very important step in sugar manufacturing. Final product quality and cost of production depend very much on its execution. For quite a long time its control was the sole responsibility of the “artisan” pan-man, but these times are over now. Instruments to provide some objective information on the process appeared in the plants around the middle of the 20th century. They were intended to provide information on syrup concentration (correlated to supersaturation) and on massecuite density or consistency (correlated to crystal content). None of the instruments in use today are able to serve well both of these basic needs. Some of the common instruments are based on the change of an electrical parameter of the massecuite (conductivity or / and capacitance). Due to their less than satisfactory operation, the frequency of the electrical signal used kept increasing. The first conductivity probes used signals of only a few kHz frequency. The RF (Radio Frequency) probes use signals in the 100 MHz range, while the fairly new microwave probes use even much higher signal frequency. It is interesting to note that the well proven method to measure liquid concentration, that is the use of refractometers dates back well over a century, and makes use of even higher frequency, that is the frequency of light. The modern process refractometer which is available since the 1980-s became the most accurate and reliable workhorse in this field.

Realising the potential and importance of the modern process refractometer, original research and development was started by PROFICON Ltd., Hungary in the second half of the 1990-s to develop new instruments providing reliable information on the most important parameter of crystallization: supersaturation, combined with automatic seeding. The first result of this effort was the SeedMaster optional software, which is available with the PR-01-S type K-PATENTS process refractometers. In a new development, the SeedMaster 2 Crystallization Transmitter And Automatic Seeding Device offers more and advanced features. Both devices are unique, represent a completely new class of instruments and are based on several decades of experience in carrying out mill-wide automatic control projects in several countries of the world.

IMPORTANT NOTICE:

Realizing that SeedMaster 2 is a device not comparable to any of the common ones used in crystallization, this manual probably discusses in more detail some special issues related to the subject, than usual. While doing so the main effort was directed to increase the realization of the importance of supersaturation in crystallization control, a long neglected field because of the lack of a reliable instrument capable to provide on-line data on it. Recommendations on some issues, for example: method of seeding, the value of supersaturation during a crystallization process are really only recommendations, and though they certainly are in line with the latest results of research in this field, it is up to the end user how she / he wants to use the instrument.The manufacturer of SeedMaster 2 can not be made responsible for any type of damage that might be caused by its use.

2 SUGAR CRYSTALLIZATION IN BRIEF 6

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2 SUGAR CRYSTALLIZATION IN BRIEF

2.1 The last step: crystallization

The main steps of sugar manufacturing are: sugar extraction (from cane or beet), juice purification and concentration, and crystallization.SeedMaster 2 was designed to provide all the vital information required to control the process of sugar crystallization on an unprecedented level. It is therefore logical to concentrate further discussions on the process of crystallization.Two methods to produce sugar crystals can be distinguished: cooling crystallization and evaporative crystallization.Most of the sugar crystallized is produced in evaporative crystallization in batch or lately in continuous evaporative crystallizers, but the basic principles of operation are the same in both types of crystallization methods. Traditionally the vacuum pan operating in batch mode became the major piece of machinery and enjoys wide use all over the world.Crystallization is a very important part of sugar manufacturing. This is a process which has a large influence on product quality and on the cost of production, both of which are very important when competitiveness is at stake.During most of its long history the control of sugar crystallization in batch pans was the undisputed authority of the pan-men, who acquired their skill during a large number of years in practice. Working mostly without any real instruments, they used only their eyes and fingers to keep the process under control. No wonder, they still are being regarded as “artisans” of their profession. However, artisans can be quite different, and quite often tend to behave rather unpredictably, which is far from being compatible with the quality- and cost-conscious requirements of industrial mass production, so representative of our times. Modern control of crystallization must rely on the reliable on-line measurement of the parameters which are vital in the control of the process performed by a local operator (manual control), or by an advanced automatic process control system (PCS).

2.2 Supersaturation: the driving force of crystallization

It is well known that crystallization can take place only in solutions which contain more solids in solution than required to saturation. In case of sugar solutions the same mass of water can dissolve different amounts of sugar depending on its temperature: the amount of sugar is larger, if temperature is higher. A saturated sugar solution therefore can be supersaturated either by decreasing its temperature (cooling), or by decreasing the mass of water (evaporation).Supersaturation is defined as the amount of sugar dissolved divided by the amount of sugar required for saturation in the same amount of water at the same temperature. We have real supersaturation only if this ratio is larger than 1,0 (saturation).Supersaturation is the driving force of crystallization: crystal growth (speed of crystallization) depends very much on this parameter. High supersaturation means faster crystal growth and vice-versa. There is no crystal growth if supersaturation is less than 1,0, in which case instead of growing, already existing crystals begin to dissolve. It is important to emphasise that supersaturation is a complex multivariable function of the liquid phase (mother liquor) parameters and should be calculated taking into account all of its governing parameters:

Supersaturation = f(C, Q, T, m, b, c) (Eq. 1.) where:

C : syrup / mother liquor concentration (%)Q : syrup / mother liquor purity (%)T : temperature (˚ C)m, b, c : syrup quality parameters (-)

Syrup quality parameters are discussed in detail in Ch. 12 APPENDIX.It follows from its definition that, among others, concentration of the mother liquor should be measured on-line, undisturbed by the presence of crystals in the massecuite in order to be able to calculate it.

2.3 Seeding methods

Seeding is a very important step in the process of crystallization, which has a large influence on the quality of the product. When completed, the crystals begin to grow in size, if supersaturation is larger than 1,0.


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Shock seeding is the traditional way of seeding. It relies on the building up of high supersaturation in the solution, when a small amount of seed crystals entered into the pan results in the formation of new crystals(nucleation). The number of these crystals keeps growing as long as the value of supersaturation is above a “safe” (nucleation-free) limit. The final number depends very much on the actual value of supersaturation, and on the time (time of nucleation) spent in the region of high supersaturation above the “safe” limit.

There are at least 3 important parameters in this method of seeding:1. the actual value of supersaturation maintained in the “seeding point” and during nucleation;2. the length of nucleation;3. the limit value of supersaturation above which nucleation begins, if there are already crystals in the

solution.

Point 1. calls for a reliable measurement of supersaturation.

Point 2. has some difficulties of its own, too. How to determine the correct length of nucleation? The method of trial and error can only be used, if supersaturation was the same all over the trials, which again calls for its measurement. Even if it is known, in case of manual control of crystallization is it possible to ensure exactly the same time for nucleation from strike to strike, even during the night shift?

Point 3. requires the knowledge of the critical supersaturation, above which nucleation begins in the presence of already existing (seed) crystals. There are not many reliable data on this limit. A recent publication (see below) provides data depending somewhat on syrup purity and temperature, too (the dependence on temperature is more pronounced with low-purity syrups). In case of high syrup purity (larger than 94 %) this supersaturation limit is about 1,12…1,13. An important point is that the formation of new (often unwanted) crystals can begin any time supersaturation exceeds the critical supersaturation limit.

CRITICAL SUPERSATURATION TO START NUCLEATION

1,1

1,11

1,12

1,13

1,14

1,15

1,16

1,17

1,18

1,19

1,2

74 76 78 80 82 84 86 88 90 92 94 96 98 100 102

SYRUP / MOTHER LIQUOR PURITY (%)

SU

PE

RS

TU

RA

TIO

N.

TEMP. 60 C

TEMP. 70 C

TEMP. 75 C

TEMP. 80 C

Fig. 2.1

(This figure is based on the equation published in:M.Saska: Boiling point elevation of technical sugar cane solutions and its use in automatic pan boiling. International Sugar Journal 2002, VOL. 104., No.1247., 500-507).

Fig.2.2 shows some of the trends typical of shock seeding. It is evident that shock seeding has quite a few uncertainties and consequences, which make its use in modern practice undesirable.


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Supersaturation SEEDING POINT

Density

Level

Motor power

Draw in Concentrate Graining Boiling Boiling Dischargeup

Fig. 2.2Full seeding is the advanced mode of seeding. In ideal case there are no new crystals formed during seeding: the full required crystal crop is supplied during seeding in the form of well prepared slurry. It is assumed that only crystal growth and no nucleation will take place during the complete length of crystallization (during a strike in batch pans), that is the number of crystals in the end product is in ideal case equal to the one of the seeding material.Besides using slurry, full seeding can be implemented by using the right amount of crystal footing (magma), too. It follows from the above that in case of full seeding and during the complete crystallization supersaturation must not exceed its limit value. This requirement may result in somewhat longer times of crystallization than accustomed, but will result in better sugar quality.

Supersaturation

Density

Level

Motor power

SEEDING POINT

Draw in Concentrate Graining Boiling Boiling Dischargeup

Fig.2.3Fig. 2.3 shows some of the trends typical of full seeding.


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NOTE:The use of slurry (or crystal footing) alone is no guarantee for correct full seeding. Besides the right amount of slurry or footing (with the right number of crystals in it) supersaturation must not exceed its limit value.

2.4 Crystal content

Good control of the process of crystallization requires some information on the crystal content of the massecuite, too. The amount of sugar needed to feed the growth of crystals increases as the surface area of the crystal mass increases. Feed syrup is supplied to fill the need. The control of crystallization in a vacuum pan, for example, should be a co-ordinated process. Control parameters, like vacuum, heating steam (vapour) pressure, feed syrup input are connected in a complex way to the massecuite parameters. The actual value of supersaturation depends on quite a few parameters (see Eq. 1.) From these, concentration depends on the rate of evaporation and syrup feed, while temperature is basically determined by the absolute pressure above the massecuite.In batch crystallization some indirect measure of crystal content is being used to signal the end of the strike.

2.5 Product quality and supersaturation

The importance of supersaturation in product quality can not be overstated. Its role in seeding has already been discussed, while Fig. 4 (scale: 1 by 1 mm) proves its effect all over the strike. In this figure a fairly wide crystal size (from 1 mm to perhaps 0,05 mm) distribution can be observed. Most probably there were much smaller size crystals, too, but they had escaped through the screen of the centrifuge only to increase the amount of recirculated crystallized sugar in the green syrup (Fig. 6). It is evident that the smaller crystals (the “young generation”) are due to spontaneous nucleation in the later phases of the strike. These crystals therefore did not have time enough to grow to a larger size till the end of the strike (it is assumed that the size of the seed crystals (the “old ones”) was fairly equal).

Fig. 2.4

In Fig. 2.5 (scale: 1 by 1 mm) among well developed crystals quite a few conglomerates (a cluster of mutually intergrown crystals) of different sizes can be observed.

Fig. 2.5

conglomerates


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It has been proved that formation of conglomerates mostly happens when the size of the crystals is in the 40to 250 micron range. This means that the formation of conglomerates in the early phase of crystallization (not long after seeding) results in large conglomerates at the end of the strike, while smaller conglomeratesin the end product are due to unwanted nucleation (because of too high supersaturation) in the later phases of the strike. Bad circulation, probably resulting in high local supersaturation in some parts of the pan also contributes to the formation of conglomerates.It is quite common nowadays that special products require well defined grain sizes, which call for a tight crystal size distribution. This can be achieved by good boiling control (including, of course, good control of supersaturation), or by screening of the product, if it has a wide size distribution. This later method, however, requires additional machinery, time and energy and naturally increases the cost of production. Besides wide crystal size distribution conglomerate content also contributes to poor product quality. It is well known that the colour of the product has strong correlation to conglomerate content, because intergrown crystals are more likely to retain some of the mother liquor during centrifuging. If conglomerate content is high, product colour can only be improved with the excessive use of water in the centrifuges, which will result – because of dissolution - in considerable loss of the crystal mass.

2.6 Cost of production and the major parameters

It has been demonstrated that wide crystal size distribution and conglomerates of varying sizes in the end product are due to excessive supersaturation, which, if not controlled properly, can be present during the complete course of crystallization (Figures 2.4 and 2.5). This proves that statements on the decreasing importance of supersaturation after seeding has been completed are totally unfounded and false. Conglomerate and fines content have very important effect on the cost of production. Too high fines content makes centrifuging difficult and results in considerable loss of already crystallized sugar through the screen baskets of the centrifuges. It is difficult to determine the amount of this loss and quite often it is neglected. It should be realised, that the number of strikes per shift, often used in practice, is not a correct measure of the rate of production. Fines and conglomerates result in recirculated sugar only to be melted, concentrated and crystallized again, the end result of which is waste of time and energy, decreased effective yield of product sugar per strike and shift, increased use of water and increased cost of production.

Fig. 2.6

It is well known that the speed of crystallization is higher if supersaturation is higher, that is the rate of production increases with increasing supersaturation. It is therefore tempting to push production by maintaining high supersaturation, but exceeding the safe limit, where spontaneous nucleation begins and the risk of conglomeration increases, too, is accompanied with the unpleasant consequences discussed above.Selecting the correct supersaturation set point trajectory for a strike is therefore a kind of compromise (or optimisation). However, any type of supersaturation control is un-conceivable without the correct on-line measurement of supersaturation.

ProductCrystals

Fines andconglomerates

Recirculatedsugar

Tank

Green liquor and fines

Productscreen

Melter

Mixer

Centrifugals


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2.7 Common instruments in use for crystallization control

There are two major types of data needed for good control of crystallization:1. supersaturation, and2. information related to crystal content.

The basic requirements concerning the sources of these data are:accuracy:

supersaturation : fairly high,crystal content : modest;

in - and on-line instruments:should provide reliable data in real time during the full course of crystallization;

long-term stability:it is a basic requirement.

Besides instruments providing data on vacuum, massecuite temperature, level and vapour pressure in the calandria, common instruments in use for boiling control measure electrical parameters of the massecuite (conductivity, conductivity and capacitance (RF sensors), viscosity / consistency, stirrer motor consumption, density / solids content (nuclear), density / solids content (microwave), boiling point rise and refractive index.

None of these instruments provide reliable and quantitative data neither on supersaturation, nor on crystal content, the real massecuite parameters that matter.

Conductivity is due to the presence of different types of ions in the syrup or mother liquor. It depends on several parameters like concentration, composition and amount of non-sugars present, crystal content and temperature. It certainly has (through syrup / mother liquor concentration) some correlation to supersaturation (see Eq. 1.), but due to changes in other parameters governing it, it is far from being able to provide reliable information on supersaturation.

Capacitance (RF sensors) depends mostly on the water content of syrup / mother liquor in a unit volume of massecuite, therefore, besides concentration it shows strong dependence on crystal content.

Viscosity of the syrup / mother liquor depends on their concentration and temperature, but instruments in use for boiling control do not have temperature compensation feature.

Consistency is the property of the liquid / solids (mother liquor / crystals) mixture. Viscosity / consistency are measured in crystallization control practice by the same instrument. Consistency, however, sharply increases with increasing crystal content. At the end of a strike consistency can be 20-30 times larger than the viscosity of the mother syrup alone.

Stirrer motor current or power consumption provide data on viscosity / consistency in a different form.

Density of the massecuite comes from two sources: density of the mother liquor and that of the solid crystals. Besides these the crystal to mother liquor ratio in the massecuite will determine its value.

Solids content of the massecuite is similarly determined by the solids content of the mother liquor, that of the crystals and by the crystal to mother liquor ratio.

The common features of all instrument types discussed above are:1. None of them is able to provide selective and accurate enough information on mother liquor concentration in the presence of crystals, therefore they are unfit to give even approximate, indirect information on supersaturation all over a strike (see Eq. 1).2. Having completed seeding all instruments discussed above provide data which are more and more governed by the increasing crystal content. It is logical therefore that these instruments can be put to good use only to provide – though indirect and only approximate - information on crystal content.

There are only two principles of measurement which can be used to measure syrup concentration selectively even in the presence of sugar crystals.Boling point rise of a solution depends – among others – on its concentration, therefore it is correlated to supersaturation. Supersaturation, however, is a multivariable function of several parameters. On the other hand: boiling point rise depends on syrup / mother liquor purity and non-sugar composition, too. Boiling point


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rise is small with high-purity syrups and therefore requires very accurate measurement. Due to these problems its use in the determination of supersaturation with the required accuracy and stability is very questionable.

Refractive index of a solution has very strong and well-known correlation to its concentration. The principle of measurement is in use all over the world since over one and a half century in laboratory, and nowadays in process refractometer types, too. The data provided meet the requirements stated earlier regarding its use in the calculation of supersaturation.

Summing up: 1. Supersaturation is the most important parameter of crystallization.2. Supersaturation is a multivariable function of several syrup / mother liquor parameters (see Eq. 1).3. Common instruments in use measure only a single parameter of the syrup or massecuite, therefore they

are unable to provide real quantitative data on supersaturation.4. Supersaturation can only be calculated on-line by taking into account all of the parameters that govern

it. It is therefore logical that reliable and accurate on-line data on syrup / mother liquor concentration are required. The only way to get them is by the use of a reliable process refractometer.

5. Information on supersaturation and on crystal content (even in indirect form) is required for advanced boiling control.

2.8 Mounting the K-PATENTS refractometer

The K-PATENTS process refractometers have proved their worth in thousands of applications including crystallization in the sugar industry worldwide. They consist of 2 main parts: the Sensor Head (1 or 2) and the Indicating Transmitterconnected by a 10 to 100 m long cable.

Mounting the Sensor Head.

In crystallizer applications it is recommended to use the long probe version providing longer insertion length. Selecting the best location to mount the Sensor Head is usually a case of compromise. Crystallizers are far from being perfect: despite the use of stirrers, circulation of the massecuite becomes more and more sluggish when the crystal content increases. This means that syrup / mother liquor concentration and temperature, which have large influence on supersaturation will not be the same in the full massecuite volume. The following considerations should be taken into account:

1. Select a location, where measured concentration is representative for the largest volume of the syrup ormassecuite. This requirement means that locations close to the feed syrup entry and above the calandria should be avoided. Too short distance from the entry point results in misleading data valid for a diluted massecuite in a relatively small volume. A too fast drop of measured concentration after opening the feed valve is real cause for concern.2. Supersaturation increases with decreasing temperature if syrup / mother liquor concentration is kept constant. This means that highest supersaturation is expected where temperature is the lowest. Temperature is the lowest at the surface of the massecuite, while it is the largest just above the calandria. Naturally, the rising surface can not be followed with the sensor. In practice temperature in the pan bottom is fairly close to surface temperature.

In practice, unfortunately enough, feed syrup most often enters the downtake just above the calandria or at the lower end of the downtake. These are rather questionable designs because of two reasons:

Due to the increasing difference between the density of the massecuite and that of the feed syrup due to increasing crystal content, syrup entering the pan reverses direction and flows upwards in the downtake, working more and more against the much needed circulation of the massecuite. This design is in complete disregard of the needs of the on-line measurement of any massecuite parameter (see point 1 above). A much better solution is when feed syrup enters the pan under the calandria through a circular ring pipe. Feed should be distributed and directed upwards at several locations around the pan wall. This solution instead of degrading, improves massecuite circulation, and provides good location under the feed pipe for instrument sensors.

Figure 2.7 shows recommended sensor locations for the two cases.


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Fig. 2.7 Recommended sensor head locations

NOTE:Sensor location in a crystallizer is a problem independent from the type of sensor used. If a separate temperature sensor is used, it should be mounted close to the refractometer Sensor Head. The same applies to massecuite density and solids content (brix) sensors as well.

Mounting the Indicating Transmitter

It is general practice to mount the Indicating Transmitter close to the vacuum pans. The enclosure must not be exposed to rain or direct sunshine. Avoid vibration.

FURTHER READING:

1. L.Rózsa : On-line monitoring of supersaturation in sugar crystallizationI.S.J., 1996, 98, 660-675

2. L.Rózsa : Sensor performance in monitoring of supersaturationI.S.J., 1997, 99, 263-268

3. L.Rózsa : The SeedMaster deviceI.S.J., 1998, 100, 601-607

4. L.Rózsa : Sucrose Solubility in Impure Cane Sugar Solutionsi.S.J., 2000, 102, 230-235

5. L.Rózsa : Sensor Selection: Still an Issue in Sugar Crystallization ControlPHILSUTEC Convention 2003, Bacolod City, PHILIPPINES

6. L.Rózsa : SeedMaster 2: A universal crystallization transmitter and automatic seeding deviceI.S.J. 2006, 108, 683-695

3 THE SEEDMASTER 2 CRYSTALLIZATION TRANSMITTER… 14

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3 THE SEEDMASTER 2 CRYSTALLIZATION TRANSMITTER AND SEEDING DEVICE

3.1 SeedMaster 2 description

The heart of SeedMaster 2 is a high performance computer specifically designed to calculate, display and transmit all of the vital parameters characterising sugar crystallization simultaneously for up to 2 crystallizers. Besides that it can perform reliable automatic seeding of the crystallizers as well. Both features require the input of some data measured on-line by 1 (or 2) K-PATENTS process refractometer(s) and by some selected instrument(s). Input of a few laboratory data and status information (digital inputs) are also required.

Based on these data SeedMaster 2 is able to calculate 7 massecuite parameters per crystallizer in real time,only 2 of which are considered adequate for the advanced control of crystallization. Some of these parameters (for example: crystal content, mother liquor purity, mean crystal size etc.), though they are important ones, are usually rarely determined by the local laboratory, if at all. Due to the time delay (dead-time) involved, these data, however, are more or less useless in closed loop, real time control of crystallization. Other instruments in use provide data only on a single massecuite parameter.

Fig. 3.1 SeedMaster 2 serving 2 vacuum pans

3.2 SeedMaster 2: a front-end device

The device was designed to be used as a “front-end” instrument mounted close to the vacuum pans or crystallizers in order to provide all of the information required by operating personnel on site. It has a large backlit LCD display and a keyboard (Fig. 3.2). Naturally enough, it has advanced digital communication features to send a large amount of acquired and calculated data on-line to a Process Control System, too.The LCD display is specified to operate in the 0 – 50 C temperature range (environment) and this applies to SeedMaster 2 as a whole, too.

DENSITY

THIRD PARTY TRANSMITTER : DENSITY

MOTOR CONS.

THIRD PARTY TRANSMITTER: MOTOR CONSUMPTION


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Fig. 3.2 The SeedMaster 2 enclosure(Display: supersaturation and crystal content)

3.3 Principle of operation

Contrary to commonly used sensors that measure massecuite parameters only indirectly linked to the really important ones (supersaturation and crystal content), SeedMaster 2 was designed to provide information on-line on all of the parameters which are important for the up-to-date control of crystallization.Its operation is based on the use of the K-PATENTS process refractometer, which became the workhorse of different industries, including sugar, when accurate on- and in-line measurement of liquid concentration is a must. Syrup / mother liquor concentration data are not disturbed by the presence of crystals, steam and vapour bubbles and the colour of the liquid. At the same time the refractometer provides data on massecuite temperature as well. This means that data on C and T (concentration and temperature) in Eq. 1. are directly provided by the refractometer. Though not advised, it is possible to use a separate temperature probe and transmitter, too. Besides these data information on mother liquor purity Q is also required for the on-line calculation of supersaturation. Mother liquor purity is equal to feed syrup purity only up to the point of seeding. When the crystals begin and continue to grow, mother syrup purity begins to drop accordingly. It is therefore not constant during the strike, and should be calculated on-line together with changing crystal content. This, however, needs the use of additional on-line data (“Third input”) from some already existing sensor (density, massecuite solids content (brix), or stirrer motor consumption). As a last resort, if none of these sensors is available, a single data from the laboratory (updated from time to time) on crystal content (% by volume) when dropping the charge (vacuum pans operating in batch mode) can be used.Finally, it is well known that feed syrup quality, characterised by its “m”, “b” and “c” parameters can show considerable changes, which have to be taken into account when calculating the massecuite parameters. Syrup quality parameters should be determined by the local laboratory (see: APPENDIX). If it is not possible, data typical for beet and cane syrups are available. Besides these some additional laboratory data are also required.

SeedMaster 2 operates in two different modes:1. in “Stand-by mode” it is waiting for the start (“activation”) of a new strike (vacuum pans

operating in batch mode); 2. in “Active mode” it is carrying out all of the calculations and operations it was designed for

(batch vacuum pans and continuous crystallizers).


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Data base START On-line inputsprogram once Parametersevery 10 sec Digital I/O

Calculated outputs Archive data

Strike ACTIVE?

ACTIVE YES STAND-BYMODE MODE Calculations operations

Archive END data

Seedingoperations

Decision based on THIRD INPUT

MASS. DENSITY MASS. SOLIDS CONT. MOTOR CONS. LAB. CR. CONT.

Calculations Calculations Calculations Calculations

END

Fig. 3.4 The basic SeedMaster 2 operations

Based on the calculated data SeedMaster 2 can be programmed to carry out automatic seeding of the crystallizer on its own, when

supersaturation, or massecuite density

becomes equal to the supersaturation or density set-point selected by the technologist or pan operator. Actual seeding is carried out by opening the seed valve (digital output) for a pre-set time interval. If seeding of the crystallizer is carried out not by SeedMaster 2, but by another device (a control system, for example), or by the operator, SeedMaster 2 must be notified accordingly by a digital input, or via digital communication.All operations discussed above can be performed independently with two crystallizers at the same time.

3.4 Calculated data

Based on the information received SeedMaster 2 carries out involved calculations on-line. These, and one or the other of the measured data used (density, solids content, motor consumption, or laboratory crystal


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content data) are combined providing information on 7 massecuite parameters (set of massecuite parameters) per crystallizer. These are:

1. supersaturation (-)2. crystal content (% by volume)3. mother liquor purity (%)4. massecuite density (kg / m)5. massecuite solids content (%)6. massecuite consistency (%)7. mean crystal size (mm)

Parameters No.1. and No.2. are the important ones for the advanced control of crystallization.Parameters No.1. … No.3. and No.7. represent a drastic change in the type of information available in real time for crystallization control, while No.4….No.6 provide accustomed data.

NOTES: 1. Any 2 out of the 7 (per crystallizer) listed above can be selected for transmission by standard (0…20 mA,

or 4…20 mA) current output. 2. All of these and some other data can be transmitted to a PC (Personal Computer), or PCS (Process

Control System) via digital communication.3. Mean crystal size data are approximate and valid only if full seeding is practiced and no dissolution

of crystals or further nucleation takes place during crystallization.

3.5 On-line data inputs

The 2 obligatory on-line (real-time) data inputs required for the correct operation of SeedMaster 2 are:

1. syrup / mother liquor concentration, and 2. massecuite temperature.

It is highly recommended to use a third on-line data input (“Third input”) as well, which can be selected from those listed below:

3. massecuite density (kg / m), ormassecuite solids content (%), orstirrer motor power consumption (kW), orstirrer motor current (A).

It does not matter what kind of instrument (nuclear, microwave etc.) is being used to measure density, or solids content. If stirrer motor consumption provides the 3rd data input, power consumption (kW) data are preferred.

3.5.1 Receiving syrup concentration data from the K-PATENTS refractometer(s)

There are several ways to transmit concentration data originating from a K-PATENTS refractometer to SeedMaster 2 ( see Ch. 7.2):

1. Standard current transmission (4 – 20 mA).The transmitter can be the refractometer itself, or the standard current may come as current output from a DCS-, or PLC-based Process Control System (PCS) already receiving the data from the refractometer. In this case an analogue input channel of SeedMaster 2 should be used.

2. Digital communication using ports COM1, COM2, or COM3.It is possible to transmit concentration (and temperature) data measured by K-PATENTS PR-01-S typerefractometer(s) by using serial data communication (RS232, RS422, RS485). SeedMaster 2 has 3 serial ports (COM1, COM2, COM3). Two of these can be used to receive data directly from 2 PR-01-S type refractometers at the same time . Cable length should be short, not exceeding 15 meters.

3. All data exchange (inputs and outputs) between SeedMaster 2 and a PCS can be implemented by using one of the COM1…COM3 ports and MODBUS SLAVE (ASCII RTU) protocol.

4. Data input (concentration and temperature) to SeedMaster 2 from a K-PATENTS PR-23 type refractometer with 1 or 2 sensor heads can be implemented by directly connecting them using the standard ETHERNET connection and UDP / IP K-PATENTS refractometer protocol.

5. All data exchange (inputs and outputs) between SeedMaster 2 and a PCS can be implemented by using the standard ETHERNET connection and TCP / IP MODBUS TCP protocol.


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3.5.2 Receiving temperature data

Massecuite temperature is always measured by the sensor probe of the K-PATENTS refractometer and may be available for transmission as standard current (4 – 20 mA) output (option). The Indicating Transmitter of the refractometer has (depending on the model used) two, or only a single current output. It is possible to use an independent temperature sensor and standard current transmitter to transmit temperature data to SeedMaster 2 as well. SeedMaster 2 has 2 (optional) RTD Pt100 type (Resistance Temperature Detector) inputs as well. In these cases the temperature sensor should be located as close to the refractometer sensor head as possible in order to measure the same sample temperature. From time to time re-calibration of the temperature transmitter is advised.

Temperature measured by the refractometer can be transmitted (together with concentration data) by using digital data communication (COM1, COM2, COM3 and ETHERNET ports), too.

All data input versions listed with concentration data input (3.5.1) are available.

NOTE:It is preferred to use temperature data measured by the refractometer.

3.5.3 Selecting the “THIRD INPUT” transmitter

Whenever available a “THIRD INPUT” transmitter should be used. If there are more than one available from those already listed, massecuite density or solids content measurements are preferred. From these two the one offering higher accuracy and stability should be used. Based on practical experience it is rather difficult to calibrate and verify these devices. It is possible to make slight corrections in the data provided by them in SeedMaster 2 itself in order to achieve a better match with more accurate refractometer and laboratory data. If stirrer motor data are used it is preferred to use motor power consumption (kW) data, because they better reflect the mechanical power required to drive the stirrer (voltage fluctuations and the changing power factor are also taken into account). As a last resort, motor current data can also be used.

3.5.4 Using laboratory data instead of “THIRD INPUT”

It is always preferred to have on-line feedback (that is: on-line information from one of the instruments listed).However, if there is no instrument available to use as “THIRD INPUT”, laboratory data on crystal content (% by volume) at the end of a strike can be used with batch vacuum pan applications. In this case the instrumentcarries out involved calculations in order to simulate the process of crystallization on-line. Based on occasional crystal content data from the laboratory, the simulated process of crystallization is adapted by the instrument using these data from the laboratory. All features of SeedMaster 2 are available.

3.5.5 Optional data inputAn optional LEVEL transmitter can be connected to one of the analogue input channels of SeedMaster 2. The level data may come from a PCS via digital communication, too. The use of level data is optional: if available, they are used to refine some of the calculations and to implement a smooth transition from one feed syrup to an other one, if feed syrups with different purities are used in the same batch strike. It can .provide additional information on site for the pan operator, too. If there is no on-line data on level, instead of level mean crystal size will be displayed on the Main Display.

3.6 Digital inputs

The 2 digital inputs (per pan) are typically contact (relay or switch) types. An “ACTIVE” digital input can be configured either as an OPEN, or CLOSED relay (or switch) contact.

3.6.1 “STRIKE ACTIVE” input DIN1

SeedMaster 2 can be operated in “Stand-by”, or in “Active” mode (Fig. 3.4). In Stand-by mode it waits for the start of a new strike (batch pans) and no calculations are performed. Displayed data might be not correct.The Active mode should be evoked by the start of a new strike (feeding syrup in the pan begins), and should usually end with the drop of the charge and motor switch OFF. In the time between two active strikes (SeedMaster 2 in Stand-by mode) the pan is usually washed and is under normal pressure. Temperature and concentration data can be quite far from their normal ranges.Information on the “ACTIVE “status of a pan or crystallizer might come from 3 sources, namely:


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from a relay or switch contact (digital input DIN1), or from the fact, that the current or power consumption of the stirrer motor exceeds a pre-set low

limit (cut off value, motor ON/OFF)), or from a PCS via digital communication..

NOTES: 1. The source of the “STRIKE ACTIVE” information can be selected from the above 3 during configuration. If motor consumption or information from a PCS is being used to synchronise the operation of SeedMaster 2to crystallizer status, digital input DIN1 can be left un-connected.2. If motor consumption (power, or current) is used as “Third input”, un-intentional stop (due to mains failure, motor problems etc.) of the stirrer motor during a strike will be treated as an “End of strike” signal.3. It is advised to use a contact input for “STRIKE ACTIVE” signalisation.

3.6.2 “SEEDED” input DIN2

In order to perform the calculations correctly SeedMaster 2 needs information on the seeding of the pan.There is no need for this input if seeding of the pan is carried out by SeedMaster 2 itself, that is if

AUTOMATIC SEEDING was configured, or the operator uses the “MANUAL SEEDING” feature regularly (not advised).

However, if seeding is carried out either by an independent process control system (PCS), or the PCS commands SeedMaster 2 to do the seeding, or manually by the operator (pan-man) without using the “MANUAL SEEDING” feature of

SeedMaster 2,the device must be notified on the seeding of the pan.In this case information may come in the form of a digital input (DIN2) signal, or via digital communicationfrom an independent control system (PCS).

NOTES: 1. Failing to provide information on seeding, when needed will result in erroneous operation. 2. When SeedMaster 2 receives information from a PCS on seeding, it will operate the same way as it would if MANUAL SEEDING were configured, that is it will OPEN the seeding valve (DO2, if connected) for the configured Ton time.

3.6.3 “CHANGE FEED SYRUP” input DIN3

If instead of a single one, 2 or 3 (maximum) feed syrups having different syrup purities are to be fed to the same batch strike the device must be informed on the execution of the change. One way to do it is to use a digital input (DIN3). Operation of this digital input will step the feed syrup number to the next one (from 1 to 2, then to the maximum 3). (For more information on feed syrup change see: 5.1.4

3.7 Data outputs

3.7.1 Data available for transmission

Besides the 6 (out of 7) massecuite parameters 4 additional ones per pan are displayed on the LCD of SeedMaster 2. Altogether 11 are available for transmission to an other device (PCS). Set of massecuite parameters:

1. supersaturation (-)2. massecuite density (kg / m)3. massecuite solids content (%)4. crystal content (% by volume)5. massecuite consistency (%)6. mother liquor purity (%)7. mean crystal size (mm)

Additional data:8. syrup / mother liquor concentration (%)9. stirrer motor consumption (if used) (kW, or A)10. temperature (˚C)11. level (%)


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3.7.2 Standard current outputs

SeedMaster 2 hardware provides 2 standard current (4 – 20 mA, or 0 – 20 mA, configurable) output channels per crystallizer. Any 2 out of the possible 11 parameters can be selected for transmission.

3.8 Digital (ON / OFF) outputs

There are 2 digital outputs available per crystallizer (DO1, DO2). These are implemented by switching transistors (open collector) capable to switch 0,1 A (DC) current at 40 VDC, max.. The outputs are protected against overload and overvoltage.

3.8.1 “SEED WARNING” output DO1

It is common practice to have the operator (pan-man) prepare the seed material (slurry) in advance and later carefully stirring it for homogenisation, and fill it in the seeding vessel when seeding of the pan approaches. The “SEED WARNING” output is configurable according to a supersaturation or density limit, and when this limit has been reached the DO1 output will be turned ON activating a lamp or horn in order to signal the operator that it is time to fill the seed slurry in its vessel. Having completed seeding this output will be turned OFF automatically.Alternatively this output can serve a different purpose, too. For example: if the seeding vessel has its own small, motor driven stirrer, this output can be used to turn this stirrer ON in advance to homogenise the slurry already filled in it.

3.8.2 “SEEDING” output DO2

Actual seeding of the pan is carried out by turning the DO2 output ON and opening the seeding valve for a selected Ton time interval (configurable). This output will be operated in 3 cases:

when AUTOMATIC SEEDING by SeedMaster 2 was configured, when MANUAL SEEDING by using SeedMaster 2 was carried out by the operator, and when it receives a command for seeding via input DIN2, or digital communication.

This same output can be used also when crystal footing is being used for seeding.

3.9 The man-machine interface

The man-machine interface of SeedMaster 2 consists of two main parts:1. Parameterization of the device is basically tailoring (customizing) it to the application, taking into account local circumstances and preferences.2. Operation of the device needs the built-in features of the different forms of data display, including strike history, alarm and test data. Besides AUTOMATIC SEEDING it also provides a tool for MANUAL SEEDING. Information on seeding details, strike status and time are also displayed.


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STRIKE ACTIVE SIGNAL

THIRD INPUT

SEEDING

ACTIVE INSTRUMENT CONFIGURATION

PASSWORD

COMMUNICATION

DISPLAY

INPUTS

MENU SET UP DIGITAL I / O

1 ANALOG OUTPUT

2 DEVICE PARAMETERIZATION TOOLS

MANUAL SEEDING SEEDING

TREND

STRIKE HISTORY DISPLAY

STANDARD DISPLAY

SYTEM INFORMATION

TEST DATA

DEVICE OPERATION TOOLS

Fig. 3.5 The main branches of the SELECTION TREE

4 TECHNICAL DATA, MOUNTING ANDELECTRICAL CONNECTIONS

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4 TECHNICAL DATA, MOUNTING AND ELECTRICAL CONNECTIONS

SeedMaster 2 is based on the use of a high-power 32 bit microprocessor and a high capacity (32 MB) memory operating under a real-time operating system. This, the application program of the device together with parameters, measured and calculated data are stored in CF (Compact Flash) memory. Parameters, calculated and archive data are stored every minute in the memory, therefore eventual loss of power supply will not result in loss of these data. The real-time clock chip (DALLAS DS12887) used in the device has its own lithium battery and needs replacement only after 10 years.In order to increase reliability and to reduce servicing, no potentiometers are used in the instrument.

4.1 Specifications

Main device features

1. On-line calculation, display and transmission of up to 7 massecuite parameters and up to 4 additional monitored data during sugar crystallization for up to 2 pans simultaneously.

2. Automatic seeding of vacuum pans based on calculated supersaturation or density set-point for seeding selected by the local technologist.

3. Collecting all calculated and measured data for the last 4 strikes in strike history archives, which can be displayed as trends with appropriate time data. Brief (numerical) supersaturation strike history (last 4 strikes).

4. Advanced communication features including the Ethernet.5. Large LCD numeric and graphic display, robust design.

Data available for transmission

1. Calculated data (all over a complete strike):1. Supersaturation (-)2. Crystal content (% by volume)3. Density (kg / m)4. Consistency (%)5. Solids content (%)6. Mother liquor purity (%)7. Mean crystal size (mm)

2. Additional data monitored in real time:1. Syrup / mother liquor concentration (%)2. Stirrer motor consumption (if used) (kW, or A)3. Temperature (˚C)4. Level (optional) (%)

Inputs for calculation

1. Process inputs:1. Syrup / mother liquor concentration measured by K-PATENTS refractometer(s)2. Massecuite temperature measured by K-PATENTS refractometer(s), or separate transmitter(s).3. Third party transmitter measuring

density, OR massecuite solids content, OR stirrer motor power, or current consumption.

4. Optional input: massecuite level.

2. Digital (ON / OFF) inputs (depending on the selected mode of operation):1. None.2. Maximum 3 (DIN1: “Strike active”, DIN2: “Seeded”, DIN3:”Change feed syrup”).

3. Laboratory data:1. Feed syrup purity (%).2. Syrup quality (“m”, “b”, “c”) parameters. Typical data and a description of a procedure to determine local parameters are provided.


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NOTE: All inputs can be also received via digital communication.

Calculated outputs

1. Analog (0-20, 4-20 mA) outputs:Any 2 of the 7 calculated massecuite parameters (per pan).

2. Digital (ON / OFF) outputs:1. DO1: Warning on approaching seeding (programmable).2. DO2: Opening the seeding valve for a selected time interval.

NOTE: All calculated and measured data can be also received via digital communication.

Process interface

Inputs

1. Analog current 8 channelsSymmetrical, galvanically isolatedRange 0(4)-20 mA, keyboard selectableInput impedance 100 OhmCommon mode voltage 50 V max.

2. RTD (Pt 100) (option) 2 channels4 wire connecting mode

3. Digital (ON / OFF) 8 channelsSignal sources: passive, contact or open collector

active, + 24 Vdcautomatic signal detection

Outputs

1. Analog current 4 channelsGalvanically isolatedRange 0(4)-20 mA, keyboard selectableMax. load 600 Ohm

2. Digital ON / OFF) 4 channelsIsolated open collector,overvoltage and short circuit protected

3. Power supply for transmitters 1 X 24 Vdc, 200 mA max.

Communication

1. Serial (COM1, COM2, COM3) 3 portsGalvanically isolated

Standards RS232, RS422, RS485 (keyboard selectable)Control signals CTS, RTS (keyboard selectable)Baud rates 1200…38400 Baud (keyboard selectable)

Length of cable RS232 15 m max. RS422 /485 1200 m max.

Protocols K-PATENTS refractometer protocolMODBUS SLAVE (ASCII, RTU)

2. Ethernet 10 6 100 Base TConnector RJ45Protocols TCP / IP, MODBUS TCP,

UDP / IP (K-PATENTS refractometer protocol)

Front panel

Display 5,7 ‘ QVGA 320x240 graphic LCDKeyboard Membrane switches with flexible foil coverLED indicators Power, Run, Alarm


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Power supply 100…240 V ac, 50 / 60 Hz; 10-25 VA 24 (18…30) Vdc

NOTE:AC and DC types of supply can be connected to the device at the same time. When AC supply is available it will be selected for use, otherwise the DC supply will be the active one. Switch-over from one to the other is automatic and bumpless.

Temperature range (ambient)

Operation 0…50 ˚CStorage - 25…70 ˚C

Enclosure

IP66, NEMA 4XSize (mm / inch) H: 267 / 10,5; W: 226 / 8,9; D: 159 / 6,25

NOTE:The SeedMaster 2 enclosure is identical to the one used by the Indicating Transmitters of the K-PATENTS refractometer family and should be mounted taking into account the same considerations, that is:

do not expose it to direct sunlight and rain, or splash water, avoid vibration, mount it vertically on an upright surface in a dry and well-lit area, do not drill mounting holes in the enclosure.

Fig. 4.1 SeedMaster 2 dimensions and mounting feet measures

4.2 Electrical connections

4.2.1 Power supply

Power to the instrument must be connected by a cable with protective earth connection. Even if DC supply is used (see Ch. 4.1), in order to maintain the accuracy of the analog inputs the protective earth connection must be used via the mains connector.

NOTES:1. There is no mains switch in the instrument! An external power switch should be used.2. Check if your mains voltage specification and that of the instrument are identical before first

switching on the instrument!

WARNING! Check if the power is off before opening the Front panel. If the red POWER LED on the Front panel is ON, turn off the power first by unplugging the power supply cable or switch it OFF with the external power switch.


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Fig. 4.2 Electrical connections

There are two screw-type terminals for power connection in the bottom of the enclosure (see Fig. 4.2). The one on the right side has 3 terminals (L: line, G: ground, N: neutral) to connect the AC power input, while the one on the left has 2 terminals with polarity markings for 24 V DC input. Both power inputs have their dedicated fuses.

4.2.2 Process inputs and outputs

Process inputs and outputs use printed circuit spring cage terminal blocks. There are 2 connection points (polarity is marked) per terminal block. Just above the power input level on the left side there are terminals for 8 analog input (AI) channels (0-20, or 4-20 mA, keyboard selectable) and a 24 V DC output (PS out) to supply power for transmitters (max. load: 200 mA).On the same level on the right side similar terminals for 4 analog output (4-20 mA) channels (AO, channels 1…4) are located. These are followed by 4 digital output channels (DO, channels 1…4), then by 8 digital inputs (DI, channels 1…8). The digital outputs have their common terminal point (common) in the rightmost position. All terminal points have their appropriate polarity markings.

4.2.3 Digital communication

There are screw-type terminals on the highest level (Fig. 4.2) for 3 serial communication ports (Com1, Com2, Com3). Their connection points are colour-coded according to the selected type of communication (black: RS232, red: RS485, blue: RS422).The Ethernet 10/100 port is located to the left of the Com1 port.


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4.2.4 I / O wirings

Analog input channels

Simplified 4-20 mA Analog Input and cabeling using external Transducer power supply.

Simplified 4-20 mA Analog Input and cabeling using the internal (max. 200 mA) Transducer power supply.

Fig. 4.3 Analog input versions

Analog output channel

Fig. 4.4 Simplified 4-20 mA Analog Output and cabeling.


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Digital input channels

Simplified Digital Input types and cabeling

Fig. 4.5 Digital input versions


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Digital output channel

Fig. 4.6 Simplified Digital Output and cabeling driving a relay.

4.3 Construction details

LCD and keyboard electronics

Fig. 4.7 Back of the front panel (protecting metal plate removed)

LCD


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The main circuit board in the enclosure

Fig. 4.8 Front panel and the main circuit board

Hardware removed from the enclosure

Front panel


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Fig. 4.9 Hardware removed

Power supply

Fig. 4.10 Power supply behind the main circuit board

5 SEEDMASTER 2 FEATURES IN BRIEF 31

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5 SEEDMASTER 2 FEATURES IN BRIEF

5.1 SeedMaster 2: OPERATOR STATION features

SeedMaster 2 represents a new tool for the on-line, on-site monitoring of crystallizers. It can be used as a local OPERATOR STATION providing a large range of valuable and until now un-available information for the pan operator. See Chapter 9 for the details.

5.1.1 CONFIGURE

CONFIGURE operations are designed to customize SeedMaster 2 according to local circumstances and preferences. This involves:

handling the use of up to 3 different purity feed syrups in the same batch strike, selection of the “STRIKE ACTIVE” information, selection of the “THIRD INPUT”, seeding details, active instrument selection, password input, communication specification.

Details of the procedures are described in Chapter 7.

5.1.2 SET UP

SET UP operations are designed to customize SeedMaster 2 according to the particularities of the application. This involves setting up the

display, different types of inputs, digital inputs and outputs, analog outputs.


5.1.3 DISPLAY

DISPLAY operations present all of the available information (measured, calculated, history, trend and alarm data, system and test information) in well organized, pre-designed forms, including:

MAIN DISPLAY STANDARD DISPLAY TRENDS STRIKE HISTORIES SYSTEM INFORMATION TEST DATA


5.1.4 MANUAL OPERATIONS

There are two different types of manual operations, which can be performed by using the SeedMaster 2 keyboard.

Manual seeding

In order to be able to cope with un-expected situations or due to local preference, it is possible to implement MANUAL SEEDING of the pan any time the pan operator decides to do so, if he previously enters the correct password. The STRIKE HISTORY feature will document faithfully the supersaturation data, when MANUAL SEEDING was implemented.Details of the procedures are described in Chapter 9.


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Change feed syrup purity

If instead of a single one, 2 or 3 (maximum) feed syrups having different syrup purities are to be fed to the same batch strike the device must be informed on the execution of the change. This can be done by selecting MANUAL OPERATIONS from the MENU followed by CHANGE FSYRUP and CHANGE. The operation will step the feed syrup number to the next one (from 1 to 2, then to the maximum 3). (For more information on feed syrup change see: 3.6.3

5.2 SeedMaster 2: TRANSMITTER features

Besides providing all the features of an advanced OPERATOR STATION on site for the local operator, SeedMaster 2 was designed to serve at the same time the needs of a Process Control System (PCS) as an INTELLIGENT REMOTE TRANSMITTER.

5.2.1 Analog output

Selected measured and calculated data can be transmitted using the standard current outputs of SeedMaster 2 (see Ch. 4, Fig. 4. 7). Specifications:

Standard current: 4 – 20 mA, or 0 – 20 mA (configurable)Type of output: individual galvanic isolationLoad: 600 ohm max.Number of outputs: 2x4

5.2.2 Digital data communication

SeedMaster 2 has advanced digital data communication features under the common name: “COMMUNICATION”. It consists of

3 communication ports (COM1, COM2, COM3) with configurable standard (RS232, RS422, RS485) features (protocols served: “K-PATENTS refractometer (PR-01-S)” and MODBUS SLAVE (ASCII, RTU)), and

1 ETHERNET port (protocols: TCP / IP, MODBUS TCP and UDP / IP (“K-PATENTS refractometer (PR-23-…)”.

By using advanced data communication it is possible to fill all of the two-way information flow requirements between SeedMaster 2 and any type of computer or control system with a compatible network connection.Details of the procedures are described in Chapter 11.

5.3 SeedMaster 2: SEEDING features

Seeding is a very critical operation which has a large effect on the final product parameters (see Ch. 2). It is therefore highly recommended to make effective use of the AUTOMATIC SEEDING feature available with SeedMaster 2.Success of the seeding, however, depends on something else, too. It is natural that before opening the seeding valve the seeding vessel must be filled with the correct volume of well-prepared and stirred slurry. In order to avoid settling of the seed crystals, filling of the vessel should be carried out not long before actual seeding. The operator or pan-man responsible for filling the vessel should be notified in time on approaching seeding. It is possible to instruct SeedMaster 2 to give a warning (digital output DO1) when the selected parameter (supersaturation or density) equals, or exceeds a “warning limit”, lower than the selected set-point for seeding. Having reached the set-point for seeding digital output DO2 will be activated to open the seeding valve for the selected (programmable) Ton time. At the same time DO1 will be turned off. If the seeding vessel is furnished with a small motor driven stirrer, digital output DO1 can be used to turn the motor automatically ON and OFF to prevent settling of the seeding crystals in the vessel.The warning on approaching seeding as well as the completion of seeding will appear on the MAIN DISPLAY. There are several ways to carry out seeding when using SeedMaster 2.

IMPORTANT NOTES:

1. It is the technologist’s responsibility to select the method of seeding (shock, or full, including the use of crystal footing), and the type (supersaturation, or density) and value of the set-point for seeding, too.

2. It is highly advised to use automatic seeding based on supersaturation.


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3. When MANUAL SEEDING is carried out by using SeedMaster 2, the seeding valve will be open for the same Ton time as when configured for automatic seeding.

5.3.1 Seeding based on DIGITAL INPUT DIN2

If configured so seeding will be carried out when digital input DIN2 becomes ACTIVE. The signal may come from a relay contact, or from a manually operated switch. The seeding valve will be operated the same way as it would if automatic seeding were configured.

5.3.2 Seeding on a command from a PCS using digital communication

In this case SeedMaster 2 simply obeys a command from a PCS by opening the seeding valve the same way as it would if automatic seeding were configured.

5.3.3 MANUAL seeding

Manual seeding might become necessary in some unusual cases. This can be done easily after entering the correct PASSWORD any time, even if a different type of seeding was configured. Though not advised, MANUAL seeding can be configured and used on a regular basis, too. See also 5.1.4.

NOTE:STRIKE HISTORY will document the supersaturation data when seeding was carried out.

5.3.4 AUTOMATIC seeding based on SUPERSATURATION

Seeding of a crystallizer can be carried out by using supersaturation calculated by SeedMaster 2 on-line, and the set-point for seeding selected by the local technologist. When calculated data becomes equal to, or larger than the supersaturation set-point, SeedMaster 2 will open the seeding valve for a selected time interval.

5.3.5 AUTOMATIC seeding based on DENSITY

Though seeding based on supersaturation is recommended, there are mills in operation where seeding practice is based on density measurement. If wished, SeedMaster 2 is able to meet this requirement, too.In this case density set-point for seeding should be used. STRIKE HISTORY will document supersaturation data when seeding was carried out.

6 START-UP AND USE 34

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6 START UP AND USE

6.1 Start up

It is recommended to complete electrical connections before switching SeedMaster 2 on.

WARNING:Before switching SeedMaster 2 ON for the first time, check if the mains supply and instrument voltage specifications are compatible.

When switched on by the mains switch it will take a minute or so until the name “SeedMaster 2” above a sugar crystal drawing, “Software Version: X.X”, and company logo “Process Control Kft., EU”

will appear on the LCD for a few seconds. It will be followed by the “MAIN DISPLAY” showing data fields for 1or 2 crystallizers with, or without actual data.

The “MAIN DISPLAY” is the starting point for SeedMaster 2 CONFIGURATION AND SET UP.

NOTES:1. There is no mains switch in the instrument! A separate one should be used. 2. It is recommended to prepare SeedMaster 2 for the actual application by starting with

CONFIGURATION followed by SET UP

6.2 Default settings

There are a few settings which are used to ensure the correct operation of SeedMaster 2.

Frequency of calculations: Massecuite parameters are calculated at 10 sec intervals for one or two crystallizers simultaneously. Timing operations, like switching ON the seeding valve for a few seconds are independent from the frequency of calculations.

Check of on-line data inputs / outputs:

Range excursions:

In order to decrease the effect of error in input and calculated data and to signal a blinking “Alarm” accompanied by logging an “Event”, most of these are checked against their ranges of operation considered “normal” during an ACTIVE strike, or the ACTIVE time of crystallization. These “normal ranges” are:

Concentration (syrup / mother liquor) 65 – 90 (%) Temperature (massecuite) 30 – 85 (˚C) Density (syrup / massecuite) 1250 – 1520 (kg/m) Solids content (syrup / massecuite) 65 – 95 (%) Level (optional) 0 – 100 (%) Supersaturation 0,7 – 2,0 (-) Consistency 0 – 100 (%) Syrup/mother liquor purity 50 – 100 (%) Crystal content (by volume) 0 – 65 (%)

Whenever the received or calculated data are out of range they will be replaced by the appropriate limit values. NOTES: 1. It is not possible to define a similar normal range in advance for motor current or power consumption,

because it can be normal in a small to any high limit range.2. The temperature range is intended to cover cooling crystallization, too.3. The “normal ranges” listed above can not be modified.4. In ACTIVE mode instead of changing input data, displaying for a longer time one of the limits of its

normal range might be an indication of transmission failure.


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5. It follows from the above that in STAND-BY mode (WAIT FOR START, WS on the MAIN DISPLAY) displayed data may be out of their normal ranges, but these excursions are not signaled as “Alarms” and are not logged in the “Events’ history” list.

Alarms

Input and calculated data are monitored and checked against two configurable limit values (High Limit, Low Limit) in order to detect, signal (“Alarm” LED) and log alarm excursions in the “Events’ history” during an ACTIVE strike.

Password Default and “Escape code” 0000

Seeding parameters

Seeding valve open (Ton) time 5 sec Syrup quality (“m”, “b”, “c”) parameters “Typical cane” Type of seeding AUTO ON SUPERSAT. Warning on seeding (supersaturation) 0.9

6.3 Device configuration

Whenever SeedMaster 2 is switched ON, the MAIN DISPLAY will come up. Later on it can be accessed any time by using the

ESCAPEkey of SeedMaster 2.

Fig. 6.1 shows one of the MAIN DISPLAY versions from the 3 possible ones. When switched ON, depending on the history of previous CONFIGURATION and SET UP operations and the present strike status, small differences in the displayed data can be observed. The figure shows a version valid for an in-active strike (WS: WAIT FOR START of a new strike). In this case there are no calculations in progress, therefore all data are set to zero. Already configured syrup purity (LI. PUR.: liquor purity) together with concentration and temperature data from an already connected refractometer are displayed.

MAIN DISPLAY 1 / 0 . 1

SEED: SUPS. =1 . 1 2 AUT STRT: 0 m WSSUPS. 0 . 0 0 LI. PUR. 0 . 0 %DENS. 0 kg/m3 LI. CONC. 0 . 0 %MA. SOL. 0 . 0 % MO. CONS. 0 . 0CR. CT. 0 . 0 % TEMP. 0 . 0 CCONSIST. 0 . 0 % CR. SIZE 0 . 0 0 mm

MENU

Fig. 6.1

CONFIGURATION and SET UP can be initiated from the MAIN DISPLAY by using the MENU soft-key. For details see Chapter 7.

6.4 Basic key operations

The 18 keys on the face-plate of SeedMaster 2 can be accessed after opening the front door of the enclosure.

NUMBER (0…9) and SIGN ( - ) KEYS

These are used to enter the selected parameters.


36

ENTER

Use it to close a data entry operation.

ESCAPE

It is used to return to the MAIN DISPLAY and to clear mistyped numbers.

SOFT KEYS

The 4 soft keys (F1…F4) fill different roles according to their names displayed just above them on the LCD. They are used in selecting a branch of the selection tree (for example: DISPLAY, SET UP, CONFIG. etc.), in moving backwards (BACK), and in selecting and accepting a data value or input signal type from an offered few (CHANGE and ACCEPT).

1 : Selects Instrument No.1. The selected instrument number is backlit.2 : Selects Instrument No.2. The selected instrument number is backlit.UP/DOWN ARROW : Selects an item.LEFT ARROW : One step back on the selection tree.

Moves the cursor left in a trend, or stops it when moving right. Stops the cursor when moving left.

RIGHT ARROW : Enters the selected item. Moves the cursor right in a TREND, or stops it when moving left. Stops the cursor when moving right.

LEFT/RIGHT ARROW : Moves the cursor when entering data.CHANGE : Modifies the current selection.ACCEPT : Identical to ENTER (will appear only after a CHANGE).BACK : One step back on the selection tree. If used before ACCEPT or ENTER, returns the previous data.ZOOM : Displays a trend in full size if only one signal is selected in TREND.ENTER : If 2 signals are selected for TREND, pushing ENTER will ZOOM

Trend 1 to full size. Keying 2 (membrane key) on the keyboard will ZOOM Trend 2 to full size. Pushing 1(membrane key) will bring back Trend 1 again (in full size).

SELECT : SELECT a signal for TREND.DOWN ARROW : Displays a selected TREND of the previous strike down to

Actual - 3.UP ARROW : Displays a selected TREND of the next strike up to the Actual one.ACK : ACKNOWLEDGE events.RESET : Resets the 2 communication error counters.

7 CONFIGURE SeedMaster 2 37

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7 CONFIGURE SeedMaster 2

7.1 Start configuration

CONFIGURATION can be accessed from the MAIN DISPLAY :

MAIN DISPLAY 1 / 0 . 1

SEED: SUPS. =1 . 1 2 AUT STRT: 0 m WSSUPS. 0 . 0 0 LI. PUR. 0 . 0 %DENS. 0 kg/m3 LI. CONC. 0 . 0 %MA. SOL. 0 . 0 % MO. CONS. 0 . 0CR. CT. 0 . 0 % TEMP. 0 . 0 CCONSIST. 0 . 0 % CR. SIZE 0 . 0 0 mm

MENU

Fig. 7.1NOTES:1. The upper half and the lower one of the LCD are distinguished as Instrument No.1, or I1, and Instrument No.2, or I2, implemented by SeedMaster 2, respectively.2. On first switch-on, by default, only I1 (the upper half of the LCD) is selected. It is signalled by the backlit area in the upper right corner (1 / XXX, where 1 is the instrument number, and XXX is the TAG of the crystallizer). The TAG can be specified during the Menu -> Set up -> Display operation. 3. Having already configured 2 active instruments, for operations with the second one push key 2 first. A similar area (2 / YYY) in the lower half of the LCD will be backlit showing the instrument selection. Key 2 will be backlit, too. Having selected the instrument or crystallizer, pushing MENU leads to the details of instrument configuration (Fig. 7.2).

1 / 1 /

Menu Manual seeding Menu Strike active signalDisplay Third inputSet up Configuration SeedingConfiguration Active instrument

PasswordCommunication

Fig. 7.2The items can be accessed by using the UP or DOWN ARROW.

NOTE: For information on the different KEY-s and KEY-OPERATIONS see: Ch. 6.4 Basic key operations.

7.2 Organizing SeedMaster 2 Input / Output traffic

The operation of SeedMaster 2 relies on the use of different types of data inputs. One group of the inputs contains data measured on-line (real-time inputs), while another group contains different parameters. It is possible to send commands, or control signals (Start of strike, Seeding) to the device, too.SeedMaster 2 outputs are measured and calculated data (real-time outputs), parameters and digital (ON / OFF) outputs.


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Fig. 7.3 SeedMaster 2 I / O traffic

SeedMaster 2 I / O traffic consists of the following types: analog I / O (AI, AO), digital I / O (DI, DO), digital communication (serial using the COMX ports, Ethernet), manual entry using the Keyboard (KEYB).


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Due to the large flexibility resulting from the use of the above resources, a large number of I / O combinations can be realized. Fig. 7.3 shows the basic I / O traffic organization of SeedMaster 2.

SeedMaster 2 relies on the use of process refractometers manufactured by K-PATENTS OY, Finland. The main data output features of the presently available K-PATENTS refractometers can be summarised as follows:

Refractometer: Analog output: Communication Communication (4 – 20 mA) (RS232, RS422, RS485) (Ethernet)

PR-01-S 1 YES, 1 port NO (single sensor) + 1 (option)

PR-23- … 2 NO YES (2 sensors)

SeedMaster 2 is prepared to be used with any combination of K-PATENTS process refractometers and can be readily integrated in a Process Control System (PCS) with compatible I / O data traffic (analog, digital I / O, and / or digital data communication) features.

Application examples

1.) Basic (or "stand alone") application, handling a single pan using a PR-01-S refractometer. Automatic seeding by Seedmaster 2. Option: SeedMaster 2 analog current outputs connected to a monitoring PCS.

SeedMaster 2 Start of strike Seed warning

Seeded DI1…8 DO1…4 Seeding valve

Change syrup

COM COM1…3 PR-01-S .

3rd input AO1…4 . PCSAI1…8 .

OptionSeedMaster 2 inputs:

concentration COM1…3 temperature 3rd input AI1…8

SeedMaster 2 outputs (option): up to 4calculated

or measured AO1…4parameters


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2.) Basic (or "stand alone") application, handling 2 pans using a PR-23-... refractometer with 2 sensor heads. Automatic seeding by SeedMaster 2. Option: Monitoring SeedMaster 2 inputs / outputs on a PCS using MODBUS serial communication.

Start of strike (A) SeedMaster 2 Seed warning (A)

Seeded (A) DI1…8 DO1…4

Change syrup (A) Seeding valve (A)

Pan 1 3rd input (A) AI1…8

Sensor (A) MODBUS UDP MODBUS PCS

PR-23-… Sensor (B) Ethernet (COM1…3)

Start of strike (B) Pan 2 Option

Seeded (B) Seed warning (B) DI1…8

Change syrup (B) DO1…4

AI1…8 Seeding valve (B) 3rd input (B)

SeedMaster 2 inputs:concentration (A) & (B) Ethernet (K-PATENTS UDP / IP)temperature (A) & (B)3rd input: (A) & (B) AI1…AI8

Seedmaster 2outputs (option):monitoring on a PCS; MODBUS communication (COM1…3)

3.) SeedMaster 2 integrated in a PCS. Parameters and commands come from the PCS using MODBUS communication. Automatic seeding by the PCS based on data from Seedmaster 2.

SeedMaster 2 Seed warning

COM COM1…3 PR-01-S MODBUS COMM.

PCSAI1…8 (COM1…3, OR Ethernet)

3rd input

Seeding valveSeedMaster 2 inputs:

concentration COM1…3 temperature 3rd input: AI1…8, OR MODBUS TCP communication

Commands, parameters from the PCS: MODBUS TCP communicationSeedMaster 2 outputs: MODBUS TCP communication


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4.) Using different types of refractometers. Data are sent to and parameters are received from a PCS using MODBUS TCP communication. Automatic seeding by SeedMaster 2.

SeedMaster 2 Concentration (1) Seed warning (1) PR-01-S

Temperature (1) DO1…4Pan 1 AI1…8 Seeding valve (1)

3rd input (1)

Seed warning (2) 3rd input (2)

Seeding valve (2)

Ethernet Sensor (A)

MODBUS UDP MODBUS TCPPan 2 PR-23-… Switch module PCS

Ethernet Ethernet

SeedMaster 2 inputs:Pan 1 concentration (1)

temperature (1)3rd input (1) AI1…8

Pan 2 3rd input (2)

concentration (2)temperature (2) Ethernet (K-PATENTS UDP / IP)

Commands and parameters from the PCS: MODBUS TCP communicationSeedMaster 2 outputs : MODBUS TCP communication

Fig. 7.4 Application examples

NOTE:To select the required mode of data entry / output key CHANGE followed by ACCEPT.

Selecting digital COMMUNICATION

If COMMUNICATION was selected, it is the user’s responsibility to send the required data via the selected communication interface (see: Ch. 11.). Example: feed syrup purity will be sent by a PCS using digital data communication:

PURITY COMMUNICATION COMMUNICATION 94.7 %

Selecting KEYBOARD (KEYB)

If KEYBOARD (KEYB) was selected, then parameter data can be entered in the next line by using the keyboard of the instrument. Example:

PURITY KEYBOARDKEYBOARD 94.7 %

All data measured on-line can be accessed on the MAIN DISPLAY.


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7.3 Configuring the STRIKE ACTIVE signal

As already discussed (see: Ch. 3.3 and Fig. 3.4) the program of SeedMaster 2 can operate in the STAND-BY, or in the ACTIVE mode, which are synchronized to crystallizer operations. Start of syrup feed followed by the actual crystallization in a vacuum pan ending with the discharge of the massecuite (a “strike”) is the ACTIVE part of the process, while the time in between two strikes (cleaning of the pan, waiting) is spent in STAND-BY mode by the instrument program (see Fig. 3.4). There are 3 different ways to inform SeedMaster 2 on strike status by using:

1. MOTOR ON / OFF2. DIN1 digital input3. COMMUNICATION

The requested mode can be selected by keying CHANGE followed by ACCEPT.

MOTOR ON/OFFThe strike (crystallization) is regarded ACTIVE whenever the motor consumption (current or power, type

is configurable) exceeds the configured MOTOR CUT-OFF CONSUMPTION (configurable). Naturally, if there are no measured (real-time) data on motor consumption available, this type of program activation can not be used.MOT. CUT-OFF CONS. is the minimal value of consumption needed to consider the strike ACTIVE. It must be specified as % of the RANGE HIGH limit selected during Set up -> Inputs (see Ch. 8.2). Acceptable limits are: 10….70 %.The selectable sources of MOTOR CUT-OFF CONSUMPTION data are:

KEYBOARD (manual data entry), or COMMUNICATION.

NOTES:1. Before trying to enter MOT. CUT-OFF CONS. data, specify its RANGE HIGH limit first in Set up -> Inputs. 2. Every motor switch ON means the START and every motor switch OFF means the END of a strike

or active crystallization process.3. Un-intentional STOP of the motor (for example: loss of power) results in the END of the strike.

CONFIG. -> STRIKE ACTIVE SIGNAL 1 /

STRIKE ACTIVE SIGNAL MOTOR ON / OFFMOT. CUT-OFF CONS. KEYBOARD KEYBOARD 15 %

CHANGE BACK ACCEPT

Fig. 7.3The example in Fig. 7.3 shows configuration details, when the MOT. CUT-OFF CONS. data is entered manually (source: KEYBOARD).

DIN1 DIGITAL INPUTDIN1 is the name (and not the physical channel number) of a digital input dedicated solely to strike activation. Its source can be connected to anyone of the available digital input channels. Channel selection and the ACTIVE state of the input can be defined during SET UP DIGITAL I/O (for the details see Ch. 8.3.). For the types of acceptable digital inputs and how to connect them see Fig. 4.8.

COMMUNICATIONThe STRIKE ACTIVE signal might come via digital data communication from a Process Control System (PCS). The signal is a fixed floating point number equal to ONE (1).STRIKE ACTIVE : ONE (1)STRIKE IN-ACTIVE: ZERO (0)


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7.4 THIRD INPUT

MAIN DATA INPUT REQUIREMENTS.

SeedMaster 2 relies on the use of on-line process data.

Besides the two obligatory data: syrup / mother liquor concentration measured by the refractometer, and massecuite temperature

it is advised to use a third on-line input, too.

The primary source of this input may be a standard current transmitter measuring massecuite density, or massecuite solids content, or stirrer motor current or power consumption (power is preferred).

As a last resort (if none of the above is available): a single data on crystal content of the massecuite (% by volume) at the end of the strike

determined by the local laboratory can also be used.

On-line data from anyone of the above 3 transmitters are preferred.Standard current transmitters can be connected directly to SeedMaster 2 using one of its analog input channels, or to a Process Control System (PCS). In this case measured data can be transmitted to SeedMaster 2 from the PCS via digital data communication.

OPTIONAL DATA INPUT REQUIREMENT: massecuite level.

Handling the use of different feed syrup purities in the same batch strike.

In some cases feed syrup purity is not constant during a batch strike. The strike is started with a feed syrup having purity P1, then later on it is continued with an other (P2), and may be it is finished with the last one (P3), where purities are gradually decreasing (P1 > P2 > P3). In practice the change from one feed syrup to the next one is carried out when level in the pan reaches some selected limit value. This can be based on real measured (on-line) data, or if it is not available, on the visual observation of the pan operator. The actual change of the feed syrup (operating the feed valves) can be implemented either by a PCS, or by the pan operator.Supersaturation, the most important parameter of crystallization depends on syrup / mother liquor purity, therefore changing feed syrup purity should be taken into account.SeedMaster 2 is prepared to handle the situation in different ways, and, as a result, with different sophistication depending on the availability of the on-line measurement of massecuite level. It is therefore important to provide information during configuration on the availability of on-line level data.If available, level data are used in other calculations as well.During configuration of THIRD INPUT a question on level measurement (LEVEL MEAS. YES / NO) has to be answered and the type of input selected (in SET UP INPUTS). If the answer was NO, then instead of LEVEL data CR. SIZE (mean size) will be displayed on the MAIN DISPLAY.When on-line level data are in use, information on mean crystal size is still available: go to Display -> Trend and select CRYSTAL SIZE.

7.4.1 Third input: MASSECUITE DENSITY or MASSECUITE SOLIDS CONTENT

Fig. 7.4 shows “Third input” configuration, when MASSECUITE DENSITY and SENSOR CALIBRATION (YES) were selected.


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CONFIG. -> 3RD INPUT 1 / CONFIG. -> 3RD INPUT -> MA. DENS. 1 /

SENSOR CALIBRATION YES

3RD INPUT: MASSECUITE DENSITY SEED CRYSTAL SIZE KEYBOARD KEYBOARD 0 . 0 1 mmPRODUCT CRYSTAL SIZE KEYBOARD KEYBOARD 0 . 6 5 mmLEVEL MEAS. KEYBOARD KEYBOARD YESLENGTH OF CRYST. TIME 1 0 6 minCONC. (REFR., SEED.) KEYBOARD KEYBOARD 7 9 . 4 %CONC. (REFR., STR. END) KEYBOARD KEYBOARD 8 0 . 4 %MA. DENS. (SEED.) 1 4 1 0 kg / m 3

CHANGE BACK ACCEPT CHANGE BACKACCEPT

a) b)Fig. 7.4

NOTE:Where the source of data is marked as KEYBOARD, data can be entered or modified directly in the same line.

Sensor calibration

After having selected the input, a question about “Sensor calibration” has to be answered. Density of the syrup up to seeding (no crystals as yet) can be calculated with high accuracy (referred to 20 °C referencetemperature) based on syrup concentration data provided by the refractometer. In most cases in practice this will be somewhat different than the density measured by a less accurate density probe. The same waydensity of the massecuite at the end of the strike can be calculated based again on measured mother liquor concentration and crystal content (% by volume, determined by the laboratory) data. In most cases it will also be a little or more different than the density measured by the density probe.If the answer to SENSOR CALIBRATION was YES, then the data in these two points (seeding and end of the strike) can be used to modify the density data measured during the complete strike by the density probe in order to have a better match of data in these two end-points. However, if the answer was NO, the original density data will be used. In this case some of the parameters are not required (these will not appear).

Third input: MASSECUITE DENSITY

The complete list of parameters:

Parameters: Remarks:SEED CRYSTAL SIZE Mean crystal size data is required (mm).PRODUCT CRYSTAL SIZE Mean crystal size data is required (mm).LEVEL MEAS. YES /NO.LENGTH OF CRYST. TIME Time from seeding till end of strike (min). Only if previous answer was NO.CONC. (REFR., SEED) Concentration (refr.) in the seeding point (%).CONC. (REFR., STR. END) Concentration (refr.) at the end of strike (%).MA. DENS. (SEED.) Density measured by the density probe in the seeding point (kg/m3).MA. DENS. (STRIKE END) Density measured by the density probe at the end of strike (kg/m3).CR. CONT. (LAB, SEED.) Crystal content by the lab in the seeding point, in % by volume, if crystal

footing is used, in other cases: 0 %.CR. CONT. (LAB, STR. END) Crystal content measured by the lab in % by volume at the end of strike.VOLUME RATIO Ratio of full to seeding massecuite volume.

NOTES:1. The last item (CR. CONT. (LAB., STR. END)) should be specified in SET UP -> INPUTS. It can not be entered, or changed here. It is automatically listed here (if specified) for completeness.2. If the answer to LEVEL MEAS. was YES, PAN MAX. LEVEL (%) will replace LENGTH OF CRYST. TIME.

The procedure is similar if instead of MASSECUITE DENSITY MASSECUITE SOLIDS CONTENT was selected as “Third input”.


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Third input: MASSECUITE SOLIDS CONTENT

Parameters: Remarks:SEED CRYSTAL SIZE Mean crystal size data is required (mm)PRODUCT CRYSTAL SIZE Mean crystal size data is required (mm).CR. CONT. (LAB, STR. END) Crystal content by the lab at the end of strike (% by volume).LEVEL MEAS. YES / NOLENGTH OF CRYST. TIME Time from seeding till end of strike (min). Only if previous answer was NO.CONC. (REFR., SEED) Concentration (refr.) in the seeding point (%).MA. SOL. (LAB, STR. END) Massecuite solids content measured by the lab at the end of strike (%).MA. SOL. (SEED.) Massecuite solids content measured by the solids content measuring

instrument in the seeding point (%).MA. SOL. (STR. END) Massecuite solids content measured by the solids content measuring

instrument at the end of strike (%).NOTE:If the answer to LEVEL MEAS. was YES, PAN MAX. LEVEL (%) will replace LENGTH OF CRYST. TIME.

7.4.2 Third input: MOTOR CONSUMPTION

PRINCIPLE OF OPERATION

Using the current or power consumption (power is preferred) as “Third input” for SeedMaster 2 offers the least expensive solution, because only an inexpensive (probably already existing) current or power transmitter is required.The current or power consumption of a motor driving the stirrer in a vacuum pan depends on the viscosity / consistency of the syrup or massecuite.Viscosity is the property of a liquid (in this case: sugar syrup, or mother liquor), characterized by the force acting against movement depending on the solution concentration and temperature.Consistency is the property similar to viscosity of a mixture of a liquid and solid particles (in this case: massecuite), depending again on solution concentration, temperature and solids (in this case: crystal) content. When crystal content is low, consistency barely exceeds the viscosity of the surrounding mother liquor. Increasing crystal content, however, increases massecuite consistency, which exceeds several times liquid viscosity. The consistency over viscosity ratio at the end of a strike can increase up to 25-30. This proves the statement that as crystallization proceeds, the output of a consistency probe used in sugar crystallization control is governed more and more by increasing crystal content.The trend of motor power consumption versus time in Fig. 7.5 shows the change of viscosity (up to point 1) and consistency (from point 1 to pan discharge) as reflected in motor power consumption. In the figure:0 Start of strike (motor switched ON)1 Seeding2 Crystal content is about 20-25 (% by volume), (PHASE 1 END)3 Crystal content is about 32-36 (% by volume)4 End of strike (motor switched OFF)

P (kW) P (kW)

PHASE 1 END PHASE 1 END

PHASE 1 PHASE 1

0 1 2 3 4 Time 0 1 2 3 4 Time a) b)

Fig. 7.5 Typical trends of single-speed motors

In Fig. 7.5 a) motor power from point 0 to 1 (the time needed to concentrate the syrup for seeding) is characterized by only a small increase in motor power. From point 1 to 2 crystal content increases to about 20-25 %. It is reflected in very slowly increasing power consumption. Between points 2 and 3 crystal growth begins to increase more rapidly, faithfully reflected in the power consumption. Finally, from point 3 crystal


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growth (by volume) becomes really fast, resulting in sharply increasing power consumption up to the end of the strike (point 4).Fig. 7.5 b) shows another similar trend, which differs from the previous one only in its 0 to point 1 section. In this case it is interesting to observe, that having completed seeding of the pan (point 1), despite an expected increase a considerable drop in motor consumption can be observed. This kind of change can be attributed to a fairly thin layer of syrup flow above the calandria during syrup concentration (from 0 to 1), which becomes wider as soon as syrup feed increases just after having seeded the pan, resulting in the observed drop in consumption.Finally, in Fig. 7.6 typical motor consumption trend is shown, when the stirrer motor operates at 2 different speeds.

P (kW)

PHASE 2 START

PH. 2PHASE 1 Low

High speed speed

TimeFig. 7.6 Typical trend of a double-speed motor

Summary: 1. When stirrer motor consumption is being used as “THIRD INPUT”, its actual use can start only after

point 2, that is when crystal content has already increased at least to some low limit value. 2. From the start of a strike up to seeding (“Syrup concentration”, 0 to 1) there is no need for any

“THIRD INPUT”. Concentration from the refractometer and temperature data are enough to calculate all output parameters.

3. During the period of “Graining” (1 to 2), or during the “High speed” operation in case of a double-speed motor, an involved simulation of crystal growth is being used to calculate all required output parameters.

4. During “Boiling” (2 to 3), and “Boiling up” (3 to 4), or “Low speed” operation in case of a double-speed motor, motor consumption data are used effectively.

5. Having completed the strike the SeedMaster 2 program, by making use of data acquired at the end of the strike, adapts some parameters to be used in the next strike during the crystal growth simulation.

CONFIGURATION

Configuration needs 17 data presented by scrolling the parameters on the screen. These are used to calculate the last 2 parameters listed at the end of the parameter list. To select the appropriate parameter use the UP/DOWN ARROW (scrolling). To select YES or NO use CHANGE. After entering / changing data use ACCEPT, or ENTER.

Terminology:

PHASE 1 END : This is the END of the first section (phase) of the strike, during which motor consumption data are useless (point 2 in Fig. 7.5).

PHASE 2 START : START of low-speed operation, when a double speed motor is being used. Typical crystal content: 35…45 % by volume (Fig. 7.6).


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CONFIG. -> 3RD INPUT -> MOT. CONS. 4 1 /

SINGL EM. CONS. (PH. 1 END) KEYBOARD KEYBOARD 3 . 3 kWCR. CONT. (PH. 1 END) KEYBOARD KEYBOARD 2 5 %MOT. CONS. (STRIKE END) KEYBOARD KEYBOARD 7 . 1 kWLEVEL MEAS. KEYBOARD KEYBOARD YESPAN MAX. LEVEL KEYBOARD KEYBOARD 7 7 %CONC. (REFR., PH.1 END) KEYBOARD KEYBOARD 8 0 . 2% PREV. ACCEPT BACK

1 / 2 SPEED

ACCEPT CHANGE BACKACCEPT

Fig. 7.7: The first page of configurationNOTE:1. All parameters can be entered by manual entry (KEYBOARD), or via digital data communication.2. CR. CONT. (PH. 1 END) and FEED SYRUP PURITY have to be entered in Set-up -> Inputs.

Depending on the answer given to the first question (1 / 2 SPEED) naming of some parameters may be different.

MOTOR: SINGLE SPEED

Parameters: Range: Notes:

1 / 2 SPEED SINGLE (single speed motor, see Fig. 7.5)MOT. CONS. (PH. 1 END) 0 < VALUE Motor consumption at PHASE 1 END

must be larger than zero (A, or kW).CR. CONT. (PH. 1 END) 10 – 45 % This is the laboratory crystal content at

PHASE 1 END. Typical value: 25 % by volume (point 2 in Fig. 7.5).

MOT. CONS. (STRIKE END) 0 < VALUE Motor consumption at the end of the strike, must be larger than zero (A, or kW).

LEVEL MEAS. YES /NO Level measurement is optional. If the answer was NO, then instead of LEVEL data CR. SIZE (mean size) will be displayed on the MAIN DISPLAY.

PAN MAX. LEVEL 40 – 100 % Only if YES was selected above.CONC. (REFR., PH. 1 END) 65 – 95 % Concentration measured by the refracto-

meter at PHASE 1 END.CONC. (REFR., STR. END) 65 – 95 % Concentration measured by the refracto-

meter at the end of the strike.TEMP. (REFR., PH. 1 END) 30 - 85 ˚C Temperature measured by the refracto-

meter at PHASE 1 END : only if the motor operates with SINGLE speed.

TEMP. (REFR., STRIKE END) 30 - 85 ˚C Temperature measured by the refractometer at the end of strike or cooling crystallization.

CR. CONT. (STRIKE END) 0 - 60 % Crystal content at the end of the strike (% by volume). It must be specified in Set up -> Inputs, and can not be entered or modified here.

SEED CRYSTAL SIZE 0.005 – 1,5 If shock, or full seeding is practiced 0.01 mm is typical. The range covers the typical values when crystal footing (magma) is used for seeding.

PRODUCT CRYSTAL SIZE 0.03 - 6 Size in mm.LENGTH OF CRYST. TIME 30 – 420 min Length of the real time of crystallization

(from seeding to the end) in minutes. After the 1st strike the time of the last crystallization can be accessed by going to DISPLAY -> TEST -> OTHER DATA


48

AVERAGE SUPERSAT. 1< VALUE From seeding to the end of strike. After the 1st strike average supersaturation during the the last strike can be accessed by going to DISPLAY -> TEST - > OTHER DATA, or usethe STRIKE HISTORY screen.

FEED SYRUP PURITY 55 – 100 % It must be specified in Set up -> Inputs, and can not be entered or modified here.

BIAS CR. CONT. - 5…+ 5 % Crystal content bias in % (by volume). Effective only above 46 %. Can be used to adjust calculated data to the final crystal content data determined by the laboratory,

MOTOR CAL. PARAM. 0 - 100 The “Motor calibration parameter” will be automatically recalculated whenever motor consumption, concentration, or temperature data are changed. Though it is possible to enter manual data, it is advised to use the data calculated by SeedMaster 2.

CRYST. PARAMETER 0 – 1,5 The “Crystallization parameter” will be auto-matically recalculated if parameters governing crystallization are changed. Though it is possible to enter manual data, it is advised to use the data calculated by SeedMaster 2. This parameter might be slightly modified bythe SeedMaster 2 program itself from strike to strike (adaptation).

MOTOR: DOUBLE SPEED (HIGH followed by LOW SPEED operation, see Fig. 7.6)

If right at the beginning DOUBLE SPEED was selected for the motor, the procedure will be very similar. The only exception: instead of parameters valid at PH. 1 END, when single speed was selected, the same parameters valid at PH. 2 START should be used.

NOTES:Most of the parameters listed above are self-explanatory. Some of them, however, need further explanation.CR. CONT. (PH. 1 END): motor: SINGLE SPEED:

In this case PHASE 1 means the part of crystallization when the change in motor consumption is very small, therefore instead of using the motor as a sensor, calculated data are based on crystal growth simulation.

CR. CONT. (PH. 2 START): motor: DOUBLE speed:This is the crystal content just after changing the motor speed to LOW. It should be determined by the laboratory. Calculated data will be based on crystal growth simulation up to switching the speed to LOW.

CRYSTAL CONTENT data (% by volume) should be determined by the laboratory.MOTOR CONSUMPTION data in different points of crystallization: these data can be easily determined by

using the DISPLAY -> TREND -> THIRD INPUT (MOTOR CONSUMPTION) trend of a strike. It is advised to check and modify consumption data when starting a new campaign, or doing maintenance work on the drive chain of the stirrer.

CONCENTRATION and TEMPERATURE data in different points are displayed on the refractometer LCD, or their trends can be used.

LENGTH OF CRYSTALLIZATION TIME and AVERAGE SUPERSATURATION (from seeding till the end of the strike) can be determined or estimated several ways: use their trend curves, go to DISPLAY-> TEST -

> OTHER DATA or to STRIKE HISTORY.

IMPORTANT:It is important that the parameters should be determined based on data of the same strike. It is advised to do a complete check of the parameters at least once at the start of a new campaign. Once entered, only changing data (for example: feed syrup purity, crystal size etc.) should be modified. This will result in the automatic recalculation of the CRYSTALLIZATION and / or MOTOR CALIBRATION PARAMETER.

7.4.3 Third input: CRYSTAL CONTENT (laboratory)

The SeedMaster 2 software contains an advanced crystal growth simulation program that can be used when no on-line “Third input” data (massecuite density, solids content, or motor consumption) are available. In this case occasional laboratory data on crystal content (% by volume) of the massecuite at the end of crystallization / strike should be used. Calculations of output data will be based in this case on the on-line measurement of


49

syrup / mother liquor concentration, massecuite temperature, and occasional crystal content data determined by the laboratory.

It is advised to check data, including crystal content from time to time, or when, for example, feed syrup purityhas been changed considerably and change configuration parameters, if needed.

NOTES:Use on-line data from a massecuite density, solids content or motor consumption transmitterwhenever available.All parameters can be entered by manual entry (KEYBOARD) or via digital data communication.

CONFIG.->3RD INPUT->CR. CONTENT 1 /

LEVEL MEAS. KEYBOARD KEYBOARD YESPAN MAX. LEVEL KEYBOARD KEYBOARD 8 7 . 5 %CONC. (REFR., SEED.) KEYBOARD KEYBOARD 8 0 . 5 %CONC. (REFR., STR. END.) KEYBOARD KEYBOARD 8 1 . 5 %TEMP. (REFR., SEED.) KEYBOARD KEYBOARD 6 9 . 5 CTEMP. (REFR., STR. END) KEYBOARD KEYBOARD 7 1 . 5 CCR. CONT. (STR. END) KEYBOARD PREV. ACCEPT BACK BACKACCEPT

Fig. 7.8 The first page of configuration

Parameters: Range: Notes:

LEVEL MEAS. YES / NO Level measurement is optional. If the answer was NO, then instead of LEVEL data CR. SIZE (mean size) will be displayed on the MAIN DISPLAY.

PAN MAX LEVEL 40 - 100 % If level is measured and available, max level in %.

CONC. (REFR., SEED.) 65 - 95 % Concentration measured by the refracto-meter when seeding.

CONC.(REFR., STRIKE END) 65 - 95 % Concentration measured by the refracto-meter at the end of the strike.

TEMP. (REFR., SEED.) 30 - 85 ˚C Temperature measured by the refracto-meter when seeding.

TEMP. (REFR., STRIKE END) 30 - 85 ˚C Temperature measured by the refracto-meter at the end of strike, or cooling crystallization.

CR. CONT. (STRIKE END) 0 – 60 % Crystal content at the end of the strike (% by volume). It must be specified in Set up -> Inputs, and can not be entered or modified here.

SEED CRYSTAL SIZE 0.005 – 1.5 mm If shock, or full seeding with slurry is practiced 0.01 mm is typical.

PRODUCT CRYSTAL SIZE 0.03 - 6 mm Mean product crystal size.LENGTH OF CRYST. TIME 30 - 420 min Length of the real time of crystallization (from

seeding to the end) in minutes. After the 1st

strike the time of the last crystallization can be accessed by going to DISPLAY -> TEST -> OTHER DATA

AVERAGE SUPERSAT. 1< VALUE From seeding to the end of strike. After the 1st strike average supersaturation during the the last strike can be accessed by going to DISPLAY -> TEST - > OTHER DATA, or use


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the STRIKE HISTORY screen.FEED SYRUP PURITY 55 - 100 % It must be specified in Set up -> Inputs,

and can not be entered or modified here.CRYST. PARAMETER 0 – 1.5 The “Crystallization parameter” will be auto-

matically recalculated, if parameters gover-ning crystallization are changed. Though it is possible to enter manual data, it is advised to use the data calculated by the

SeedMaster 2.

7.5 SEEDING

The configuration of seeding is straightforward (Fig. 7.9).

CONFIG. -> SEEDING 1 / 0. 1

SEEDING VALVE 5 sAUTO SEED ON SUPERS. WARNING KEYBOARD KEYBOARD 0 . 8SET- POINT KEYBOARD KEYBOARD 1 . 12

CHANGE BACKACCEPT

Fig. 7.9Parameters:

SEEDING VALVE Value to be entered is the time in seconds during which the dedicated digital output DO2 to the seeding valve will keep it OPEN. (See Set up -> Digital I/O, Ch. 8.3).

There are different ways to initiate seeding:

MANUAL SEED Select MANUAL OPERATIONS and MANUAL SEED. PASSWORD is required to do manual seeding. Seeding is carried out by using SeedMaster 2 according to the data specified above. Accordingly, no WARNING digital output (DO1) and warning message on the MAIN DISPLAY will be shown. The output to the seeding valve (DO2) operates the same way as if AUTO SEED had been configured.

SEEDING on DIGITAL In this case digital input DIN2 (in its ACTIVE state) commands SeedMaster 2 to carry out seeding. The digital input can be a contact (a simple manual switch or relay), or a digital output (contact, transistor collector, or pulse type) operated by a Process Control System (PCS). In response SeedMaster 2 will operate the DO2 digital output the same way as if AUTO SEED had been configured.

SEEDING using digital data 1. Seeding is the responsibility of a PCS, which commands SeedMaster 2 COMMUNICATION via digital data communication to carry out seeding. In response

SeedMaster 2 will operate the DO2 digital output the same way as if AUTO SEED had been configured (see page 88).2. If the PCS operates the seeding valve directly, the DO2 digital output of SeedMaster 2 should be left unconnected. SeedMaster 2 has to be notified on the seeding operation (digital data communication, or digital input DIN2).

AUTO SEED Seeding is carried out automatically by SeedMaster 2. There are 2 versions:AUTO SEED on SUPERSATURATION, andAUTO SEED on DENSITY set point.


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Appropriate WARNING and SET POINT values should be entered. The DO1 digital output will be turned ON when supersaturation, or density exceeds the selected value for WARNING. Similarly, the DO2 digital output will be turned ON to open the seeding valve for the selected time interval when supersaturation or density equals, or exceeds the selected SET- POINT.

NOTES:1. Selecting MANUAL SEED means that seeding is carried out on a regular basis using the “Manual

seed” selection in the Menu. However, even if any other type of seeding had been configured previously, manual seeding can be performed at once any time as an exception by selecting “Manual seed”. Password is needed.

2. If the seeding valve is operated directly by a PCS based on data received from SeedMaster 2, by configuring AUTO SEED and selecting the same SET- POINT (supersaturation, or density) for seeding as the one used in the PCS will result in approximately synchronous operation of the two devices. This means that both will attempt to open the seeding valve at the same time, but only the PCS will succeed, because in this case the DO2 digital output of the SeedMaster 2 should be left unconnected. The advantage: there is no need for any outside information (digital input DIN2, or information via digital data communication) on the completion of seeding performed by the PCS. Not to forget: the set-points of seeding in the two devices must be identical!

3. In any case: SeedMaster 2 always needs information in time when seeding was carried out. This may come from any one of the outside sources (Digital input, or COMMUNICATION), or it can be self-generated (MANUAL or AUTOMATIC seeding).

7.6 ACTIVE INSTRUMENT

SeedMaster 2 can serve up to 2 vacuum pans or crystallizers. The device can be configured to serve only one (I1, or I2), or 2 instruments (see: Ch. 7.1) simultaneously. Configuration is very simple (Fig. 7.10).

CONFIG ->ACTIVE INSTRUMENT 1 /

ACTIVE INSTRUMENT: BOTH

CHANGE BACK ACCEPT

Fig. 7.10

Possible selections: NO. 1, NO. 2, and BOTH

7.7 PASSWORD

Password is needed to carry out MANUAL SEEDING of the crystallizer. The password is a 4-character number, replaced by stars when typing.The default password number: 1324.


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CONFIG ->PASSWORD 1 /

ENTER OLD PASSWORD : * * * *ENTER NEW PASSWORD : * * * *RETYPE NEW PASSWORD : * * * *

CHANGE BACK ACCEPT

Fig. 7.11

The old password can be changed by entering the old one followed by a new one twice (Fig. 7.11). When found correct, the text PASSWORD CHANGED!will be displayed.

NOTE:In order to prevent the situation when due to a forgotten password MANUAL SEEDING becomes impossible, the number 0000 (Escape code) as OLD PASSWORD will be accepted.

7.8 COMMUNICATION

COMMUNICATION may use one or more of the 3 serial communication ports or the ETHERNET port of SeedMaster 2.

7.8.1 Using the serial communication (COMX) ports.

Fig. 7.12 shows the configuration details when a serial port (COM1) was selected.

1 / 0 . 1 1 / 0 . 1

Menu Com port Menu Com1Ethernet Com2

Configuration Configuration Com3

Communication Communication

Com port

a) b)


53

CONFIG ->COMMUN. ->COM1 PORT 1 / 0 . 1

PORT NAME COM1DEVICE NR. 1 / 0 . 1TYPE RS232

FLOW C. NOBAUDRATE 9600DATA BITS 8

STOP BITS 1PARITY NOPROTOCOL K-PATENTS SLAVEMODE ASCII

CHANGE BACK ACCEPT

Fig. 7.12 Configuring the SeedMaster 2 – K-PATENTS PR-01-S communication using the COM1 port . The possible selections:

PORT NAME COM1 (already selected)DEVICE NR. 1 / 0.1 ; 2 / 0.2TYPE RS232, RS485, RS422 MD, RS422 PP

(MD: MODBUS; PP: POINT-TO POINTFLOW C. NO, RTS/CTS, XOFF/XONBAUDRATE 1200, 2400, 4800, 9600, 19200, 38400DATA BITS 7, 8, 9STOP BITS 1, 2PARITY NO, ODD, EVENPROTOCOL K-PATENTS SLAVE, MODBUS SLAVEMODE ASCII

Terms used:K-PATENTS SLAVE It is the protocol used by the K-PATENTS PR-01-S type

process refractometer.MODBUS SLAVE If selected,

MODB. DEV. ADDR.: 21RESPONSE TIME : 1 msec

7.8.2 Using the ETHERNET.

Fig. 7.13 shows the configuration details when using the ETHERNET.

1 / 0 . 1 CONF.->COMM.->ETHER.->SEEDM. 2 1 / 0.1

Menu SeedMaster 2 IP ADDRESS 1 9 2 . 1 6 8 . 0 . 1 0 2Refractometer NETWORK MASK 2 5 5 . 2 5 5 . 2 5 5 . 0

Configuration GATEWAY 1 9 2 . 1 6 8 . 0 . 1PROTOCOL MODBUS TCP

Communication MODB. DEV. ADDR. 0

DHCP SERVER NOEthernet

BACK

a) b)


54

CONF.->COMM..->ETHER.->REFRACT. 1 / 0.1

IP ADDRESS 1 9 2 . 1 6 8 . 0 . 2 0 0

BACK

c) Fig. 7.13 Configuring the SeedMaster 2 – K-PATENTS PR-23 communication using the Ethernet.

To change IP ADDRESS, NETWORK MASK, or GATEWAY data use the LEFT/RIGHT arrow.Possible selections:

MODBUS DEVICE ADDRESS 0 – 99DHCP SERVER YES, NO

The MODBUS TCP protocol is fixed.

7.8.3 Organizing the two-way data transfer.

Data measured on-line by the instruments can be sent either directly to SeedMaster 2 or to the PCS. In the later case the PCS will transmit them to SeedMaster 2 for use. The CONFIGURATION and SET UP parameters of SeedMaster 2 will tell the device where to get these data from (see Ch. 7.2).Communication between SeedMaster 2 and a PCS may operate in both ways and it must be based on the exchange of fixed data fields containing data registers. It is the user’s responsibility to organize the data fields containing the registers and program the communication in the PCS.For a detailed description of communication and data exchange see Ch. 11.

NOTE:The communication program of the PCS should be configured taking into account the organization of data in SeedMaster 2. Naturally if two instruments (I1 and I2) are active, both of them should have their own data fields in the PCS.

8 SET UP SeedMaster 2 55

55

8 SET UP SeedMaster 2

Actual use of SeedMaster 2 can follow only after having completed the CONFIGURATION and SET UP operations. It is advised to start with CONFIGURATION.SET UP defines some display parameters and the details of data inputs and outputs.

8.1 Set up DISPLAY

Set up DISPLAY can be accessed from the MAIN DISPLAY:

SEEDED MAIN DISPLAY 1 / 0 . 1 SEEDED MAIN DISPLAY 1 / 0 . 1

SEED: SUPS =1 .12 AUT STRT: 141M BU SEED: SUPS =1 .12 AUT STRT: 141M BUSUPS. 1 . 1 4 LI. PUR. 9 2 .2 % SUPS. 1 . 1 4 LI. PUR. 9 2 .2 %DENS. 1 4 8 1 kg/m3 LI. CONC. 8 1 . 2 % DENS. 1 4 8 1 kg/m3 LI. CONC. 8 1 . 2 %MA. SOL. 8 8 . 7 % MO. CONS. 3 6 . 4 A MA. SOL. 8 8 . 7 % MO. CONS. 3 6 . 4 ACR. CT. 4 1 . 3 % TEMP. 6 9 . 8 C CR. CT. 4 1 . 3 % TEMP. 6 9 . 8 CCONSIST. 7 8 . 2 % LEVEL 7 7 . 5 % CONSIST. 7 8 . 2 % LEVEL 7 7 . 5 %

WARNSD MAIN DISPLAY 2 / 0 . 2

SEED: SUPS =1 .12 AUT STRT: 21M SCSUPS. 1 . 0 5 LI. PUR. 9 5. 2 %DENS. 1 4 0 1 kg/m3 LI. CONC. 8 1 . 2 %MA. SOL. 8 1 . 2 % MO. CONS. 3 6 . 4 ACR. CT. 0 . 0 % TEMP. 6 9. 8 CCONSIST. 2 8 . 2 % LEVEL 3 7 . 5 %

MENU 2 1 2 1 MENU 1

Fig. 8.1

NOTES:1. The upper half and the lower one of the LCD are distinguished as

Instrument No.1, or I1, and Instrument No.2, or I2, Implemented by SeedMaster 2, respectively.

2. If both instruments are active, that is there are two crystallizers served, the appropriate instrument must be selected first. By default, I1 (the upper half of the LCD) is selected. It is signaled by the backlit area in the upper right corner (1 / XXX, where 1 is the instrument number, and XXX is the TAG of the Crystallizer), and by the backlit number in the lowest row of the screen.

3. For operations with the second crystallizer push key 2 first. A similar area (2 / YYY) in the lower half of the LCD will be backlit showing instrument selection.

After having selected the instrument pushing MENU brings up the screen shown in Fig. 8.2, where “Set up” should be selected. The selected item is shown inverted (white characters on black background).

1 / 0 . 1

Menu Manual seedingDisplaySet upConfiguration

Fig. 8.2NOTE: For information on the different KEY-s and KEY-OPERATIONS see: Ch. 6.4 Basic key operations.

Entering the selected Display leads to the details of display set up (Fig. 8.3 a) and Fig. 8.3 b)).


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1 / 0 . 1 SET UP -> DISPLAY 1 / 0 . 1

Menu Display TIME SCALE 20 MIN . / MARKInputs DATE AND TIME 17:14:45

Set up Digital I/O TAG 0 . 1

Analog output STANDARD DISPLAY SUPERS . - MA . SOL.

CHANGE BACKACCEPT

a) b) Fig. 8.3

TIME SCALE The time (horizontal) scale of TREND-s will be defined by selecting 10, 20, 40 or 60 minutes/mark.

DATE AND TIME Set or change current date and time. (CHANGE (Fig.8.4 a), LEFT/RIGHT ARROW, enter new

data, ACCEPT or ENTER, BACK (Fig.8.4 b))

SET UP -> DISPLAY 1 / 0 . 1 SET UP -> DISPLAY -> DATE AND TIME 1 / 0 . 1

TIME SCALE 20 MIN./MARKDATE AND TIME 17:14:45 OLD TIME: 2005 - 02 - 24 17 : 14 : 45TAG 0 . 1STANDARD DISPLAY SUPERS . - MA . SOL. NEW TIME: >2005 - 02 - 24 18 : 32 : 12

ACCEPT BACK BACKCHANGE BACK

a) b)Fig. 8.4

TAG There is an area in the upper right corners of the two instruments reserved for TAG entry: 1 / XXX and 2 / YYYHere 1 and 2 (fixed) are used to number the two independent instruments (I1, I2)implemented by SeedMaster 2, while XXX and YYY denote user configurable TAG-s. The first character can be used to identify a group of pans or crystallizers, for example:0: refinery product, 1: first (or “A”) product, 2: second (or “B”) product etc., while the remaining 2 characters can be used to number the pans or crystallizers belonging to a group. Alternatively, the second character can be the decimal point, too.

STANDARD DISPLAY Contrary to the MAIN DISPLAY which lists 10 data per crystallizer, this type of data display can be used to display only 2 selected ones per crystallizer, but with much larger characters. Any 2 from the 11 data (if available) can be selected. (CHANGE (Fig. 8.5 a), select signal in Fig. 8.5 b), CHANGE, ACCEPT or ENTER)


57

SET UP -> DISPLAY -> 1 / 0 . 1 SET UP -> DISPLAY -> ST. DISPLAY 1 / 0 . 1

TIME SCALE 20 MIN./MARK SIGNAL 1: SUPERSATURATION

DATE AND TIME 17:14:45 SIGNAL 2: DENSITYTAG 0 . 1STANDARD DISPLAY SUPERS . - MA . SOL.

CHANGE BACK ACCEPTCHANGE BACK

a) b)

Fig. 8.5

8.2 Set up INPUTS

8.2.1 Data types and specifications

Calculations running in SeedMaster 2 rely on 2 types of data inputs:1. data measured on-line (real-time data) by some instruments, and2. data determined time to time in the local laboratory.

The possible types of data sources are (see Ch. 7.2):On-line data : Transmitter, Communication.Laboratory data : Transmitter, Keyboard, Communication.

Inputs from standard current transmitters.SeedMaster 2 has 8 individually isolated standard current (4-20 mA, or 0-20 mA, configurable) input channels. These can be connected to any device (including traditional transmitters and PCS-s) capable to transmit measured data as standard current output.

Inputs from K-PATENTS PR-01-S type process refractometer(s).One or both of the data (concentration, temperature) measured on-line by a K-PATENTS refractometer can be transmitted to SeedMaster 2 by using one or two out of its 3 Serial Communication Ports (COMX).

Inputs from the K-PATENTS PR-23-…type process refractometer(s).One or both of the data (concentration, temperature) measured on-line by K-PATENTS refractometer(s) can be transmitted to SeedMaster 2 by using the Ethernet. Up to two sensor heads can be connected to the Indicating Transmitter (ITR) of a PR-23-… type refractometer.

Inputs transmitted from a PCS using digital COMMUNICATION.If the instruments are already transmitting their data to a PCS, one or all of these data together with laboratory data can be transmitted to SeedMaster 2 by using digital data communication. Communicationmay be based on the use of one of the 3 COMX Ports, or the ETHERNET.

Laboratory data

Some laboratory data, like feed syrup purity (%) and crystal content (at the end of strike, % by volume) can be entered using standard current (4-20 mA), keyboard manual entry, or digital data communication (COMX port, or Ethernet).NOTE: Feed syrup purity can be sent as standard current only if purity is constant all over the strike (one feed syrup only).Syrup parameters (“m”, “b” and “c”) can be entered by keyboard manual entry, or by digital data communication (COMX port, or Ethernet).

SUMMARY OF DATA INPUTS: On-line (real-time) data:

Mother liquor concentration (%) Temperature (˚C)


58

Massecuite density (kg/m), OR Massecuite solids content (%), OR Stirrer motor consumption (A, or kW) Level (%) (optional)

Laboratory data: Crystal content (at the end of strike) (% by volume) Feed syrup purity (%) Syrup parameters (- )

SET UP -> INPUTS 1 / 0 . 1 SET UP -> INPUTS -> MO. LIQ. CONC. 1 / 0 . 1

MO. LI. CONCENTR. SERIAL KP.MO. LIQ. CONCENTR. COMMUNICATION RANGE 65 - 90TEMPERATURE COMMUNICATION LOW LIMIT 66 %MASSECUITE DENSITY COMMUNICATION HIGH LIMIT 85 %MOTOR CONSUMPTION TRANSMITTER ENGINEERING UNIT %CR. CONTENT (LAB.) COMMUNICATIONLEVEL TRANSMITTERFEED SYRUP DATA KEYBOARDSYRUP PARAMETERS KEYBOARD

CHANGE BACKCHANGE BACK

a) b) Fig. 8.6

Fig. 8.6 a) shows an actual input set up (here it is assumed that THIRD INPUT has already been configured as MASSECUITE DENSITY, see Ch. 7.3.1). By keying CHANGE (Fig. 8.6 a)) other available modes of transferring concentration data (for example: TRANSMITTER) will be offered for selection.

NOTES: 1. “THIRD INPUT” should be defined during CONFIGURATION. The selected THIRD INPUT (in Fig.

8.6 a): MASSECUITE DENSITY) will appear on the display, but the (non-selected) MASSECUITE SOLIDS CONTENT will be missing and vice versa.

2. MOTOR CONSUMPTION will be always listed, because its data might be used not only as THIRD INPUT when selected, but as data needed to detect the STRIKE ACTIVE state as well (see Ch. 7.3).

3. A limited small temperature bias (+ / - 5 C) can be added to the measured temperature data.

Specifying RANGE data.

Having selected the appropriate item (Fig. 8.6 a)) use the RIGHT ARROW to enter RANGE data (Fig. 8.6 b)). Pushing CHANGE will bring up the screen shown in Fig. 8.7 to do the data entry.

SET UP -> INP. -> CONC. -> RANGE 1 / 0 . 1

MIN. MAX.CURRENT VALUE : 6 0 9 0

NEW VALUE : 6 5 9 0

BACK BACK BACK ACCEPT

Fig. 8.7


59

The procedure is similar with all data source types. The new RANGE data must be within the limits specified by the default values of the same parameter (see Ch. 6.2).These RANGE data are used to detect RANGE EXURSIONS documented in the 3 different lists on EVENTS.

Specifying ALARM LIMIT data.

LOW LIMIT and HIGH LIMIT data can be entered one by one (see Fig. 8.6 b)).

NOTES:1. In the STRIKE ACTIVE state data inputs and data outputs are monitored for RANGE EXCURSIONS. If

detected, the excursions will be logged complete with their names and time stamps in the EVENTS’ HISTORY, and the effected data will be replaced for the calculations by their appropriate range limit values (RANGE MIN., or RANGE MAX.).

2. In the STRIKE ACTIVE state data inputs and data outputs are monitored for ALARM EXCURSIONS. If detected, the excursions will be logged complete with their names and time stamps in the EVENTS’ HISTORY without any further action.

Engineering units.

The ENGINEERING UNIT can not be changed: it is automatically selected according to the type of the selected THIRD INPUT. The two exceptions are MOTOR CONSUMPTION, in which case A, or kW, and TEMPERATURE, where Celsius ©, or Fahrenheit (F) can be selected by using CHANGE and ACCEPT or ENTER.

Specifying TRANSMITTER PARAMETERS.

If TRANSMITTER is specified as an input source, further specification is needed (Fig. 8.8).

SET UP -> INPUTS -> LEVEL. 1 / 0 . 1

LEVEL TRANSMITTERCLEARSTANDARD CURRENT 4 - 20 mARANGE 0 - 100LOW LIMIT 5 %HIGH LIMIT 8 2 %CHANNEL NOT SELECTEDENGINEERING UNIT %

CHANGE BACK ACCEPT

Fig. 8.8

NAME (signal) Selected source: TRANSMITTERCLEAR Clears (makes free) an already reserved ANALOG INPUT CHANNEL of SeedMaster 2.STANDARD CURRENT 0-20 mA, or 4-20 mA can be selected.RANGE (TRANSMITTER) Select RANGE to change it, then enter new data in the

upcoming next picture similar to Fig. 8.7. RANGE MIN. and MAX. data are determined by the standard current transmitter: 4 (or 0) mA current specifies RANGE MIN. and 20 mA current specifies RANGE MAX.

LOW and HIGH LIMIT-s Signal LOW and HIGH limits are used in detecting alarm limit excursions during the ACTIVE part of a strike. These result in a lit or blinking ALARM LED on the faceplate of the instrument.

CHANNEL Selection can be changed (available free channels will be presented one by one for selection).An already selected analog input channel can be freed. (Select CLEAR, then CHANGE). In response the text in the CHANNEL row will change to: NOT SELECTED.


60

NOTE: The TRANSMITTER RANGE specified here has nothing to do with the detection of RANGE EXCURSIONS. It is needed to “translate” the standard current (0 / 4 to 20 mA) into meaningful measured data (for example: temperature: 71,5 C).

8.2.2 Handling the use of several feed syrups with different purities.

In some cases feed syrup purity is not constant during a batch strike. The strike is started with a feed syrup having purity P1, then later on it is continued with an other (P2), and may be it is finished with the last one (P3), where purities are gradually decreasing (P1 > P2 > P3). In practice the change from one feed syrup to the next one is carried out when level in the pan reaches some selected limit value. This can be based on real measured (on-line) data, or if it is not available, on the visual observation of the pan operator. The actual change of the feed syrup (operating the feed valves) can be implemented either by a PCS, or by the pan operator.Supersaturation, the most important parameter of crystallization depends on syrup / mother liquor purity, therefore changing feed syrup purity should be taken into account.Depending on whether on-line data on massecuite level are available, or not, there are different ways to handle changing feed syrup purity.

Real-time data on level are available.

There are 2 ways to handle changing feed syrup purity.

AUTOMATIC: In this case up to 3 feed syrup purities (P1, P2, P3 in descending order) and up to 2 level limits (L1, L2 in increasing order) can be specified during SET UP SYRUP PARAMETERS.Calculations in SeedMaster 2 will be started with purity P1. When measured level reaches L1, calculations will take into account the change of feed syrup purity from P1 to P2. If use of 3 different purities was specified, the change at level L2 will initiate the use of P3 from that point up to the end of the strike.NOTE: The availability of level measurement will result in a smooth transition when the change(s) take place.

MANUAL : This is a special case of AUTOMATIC, meaning that if AUTOMATIC operation was specified during SET UP, it is still possible to initiate feed syrup change any time either by using digital input (DIN3), if available, or to use the KEYBOARD (MANUAL OPERATIONS).NOTE: The availability of level measurement will result in a smooth transition when the change(s) take place.

There are no real-time data on level are available.

MANUAL : Feed syrup purities (P1, P2, P3) and level limits (L1, L2) have to be specified the same way as in the former case, where level data are available.It is the operator’s or the control system’s responsibility to initiate the actual change of feed syrup when assumed level equals the specified one. Besides that, SeedMaster 2 has to be notified on the change either by digital input DIN3, or by CHANGE FEED SYRUP (MANUAL OPERATIONS).NOTE: Due to the lack of measured data on level, the transitions will result in small steps when they take place.

IMPORTANT:1. In practice feed syrup with the highest available purity (P1) is being used during the major part of a

strike. The volume of feed syrups with lower purities usually is not large as compared to the volume of feed syrup of purity P1.

2. Due to the above practice, the effect of changes in feed syrup purities effects only the last part of a strike (supersaturation will be a little bit lower than is the case when the highest purity (P1) syrup is in use all over the strike).

3. Cases when feed syrup would be changed from a lower purity to a higher one (going backwards) should be avoided.

4. SeedMaster 2 itself will not really carry out the feed syrup change (it will not operate any feed valve). It is assumed, that it will be done by a PCS, or by the pan operator in harmony with the specified data (P1, P2, P3, L1, L2).

Fig. 8.9 shows a possible set up, where 3 different feed syrup purities and appropriate level limits with AUTO feed syrup change have been specified.


61

SET UP -> INPUTS 1 / 0 . 1 SET UP -> INPUTS -> FEED SYR. PURITY. 1 / 0 . 1

FEED SYR. PURITY KEYBOARDMO. LIQ. CONCENTR. COMMUNICATION NO. OF DIFF. PURITIES 3TEMPERATURE COMMUNICATION PURITY NO1 95 %MASSECUITE DENSITY COMMUNICATION PURITY NO2 91 %MOTOR CONSUMPTION TRANSMITTER PURITY NO3 88%CR. CONTENT (LAB.) COMMUNICATION AUTO CHANGE YESLEVEL TRANSMITTER LEVEL NO1 68 %FEED SYRUP DATA KEYBOARD LEVEL NO2 75 %SYRUP PARAMETERS KEYBOARD LEVEL MAX 82 %

RANGE 50-100LOW LIMIT 65%

HIGH LIMIT 96%ENGINEERING UNIT %


a) b)Fig. 8.9 Handling different feed syrup purities

8.2.3 Set up SYRUP PARAMETERS.

The important feed syrup quality parameters “m”, “b” and “c” can be entered by using the SET UP -> INPUTS -> SYRUP PARAM. display (Fig. 8. 10), if KEYBOARD entry was previously selected (see Fig. 8.6 a)).

SET UP -> INPUTS -> SYRUP PARAM. 1 /

TYPICAL BEET TYPICAL BEET m: 0 . 1 7 8

b: 0 . 8 2c: - 2 . 1

CHANGE BACK ACCEPT

SYRUP PARAM.

Fig. 8. 10Selecting the quality parameters (see Ch.12.1):

There are 2 fixed (“built in”) sets of quality parameters called “TYPICAL BEET” and “TYPICAL CANE”.

The parameter data:TYPICAL BEET m: 0.178 TYPICAL CANE m: - 0. 06265

b : 0.82 b : 0.982c : - 2.1 c : - 2.1

The listed data on beet are regarded as typical (source: McGINNIS: Beet Sugar Technology, 3rd Edition), while those on cane are based on Thieme’s data (L. Rózsa: Sucrose solubility in impure cane sugar solutions, International Sugar Journal, May 2000).

Besides the 2 fixed sets of parameters it is possible to select LABORATORY as well:

m: b : c :

In this case quality parameters determined by the local laboratory can be entered.

NOTES:1. It is advised to use local syrup quality parameters whenever possible.2. The description of a procedure to determine these parameters can be found in the “APPENDIX”.


62

3. Setting m = c =0 (with any value of b) will result in a constant saturation function value Fsat = 1,0. This is the case of a pure sucrose solution, that is non-sugar content and its effect on solubility will be neglected.

8.3 Set up DIGITAL I / O

DIGITAL INPUTS (see Chapters 3.6.1, 3.6.2)

There are 8 digital input (DIN) channels. These can be anyone of the 3 possible input types (see: Ch. 4.1,Figure 4.5). There are 2 digital inputs per crystallizer which can be used: STRIKE ACTIVE and SEEDED inputs.

During a digital input set up operation the terminology familiar with the use of relays is used. An input is regarded ACTIVE, when a contact type input is CLOSED, or OPEN (configurable).For the 3 selectable input types OPEN and CLOSED has the following meaning:

Input : Contact Transistor collector Pulse

OPEN : Open contact Transistor is non-conducting Pulse amplitude is zeroCLOSED: Closed contact Transistor is conducting Pulse amplitude is high

The STRIKE ACTIVE and SEEDED information might come from different sources determined during configuration (see: Ch. 7.3, 7.5). Set up of a digital input is required (and possible) only if DIN1, DIN2 and / or DIN3 was already selected during configuration.

STRIKE ACTIVE input (DIN1):

The STRIKE ACTIVE DIGITAL INPUT can be used to synchronize SeedMaster 2 operations to the crystallizer. DIN1 is the name (and not the channel number) of a digital input dedicated solely to strike activation.The use of digital input use is not obligatory (see Ch. 7.3). In the example of Fig. 8.11 a) the STRIKE ACTIVE information is provided by the previously configured DIN1 digital input. Its source can be connected to anyone of the free digital input channels. In the example of Fig. 8.11 a) it should be connected to Channel DI_3 (see Fig. 4.2).

SET UP -> DIGITAL I / O 1 / 0 . 1 SET UP -> DIGIT. I/O -> STRIKE ACT. 1 / 0 . 1

CH . TYPE ACTIVE CHANNEL DI_3

IN ACTIVE CLOSEDSTRIKE ACTIVE : DI_3 DIN1 CLOSEDSEEDED : AUTO - ON SUPERS.CHANGE SYRUP : AUTO

OUTSEED WARNING : DO_1 DO1 ONSEED VALVE : DO_2 DO2 ON


a) b)Fig. 8.11

In Fig. 8.11 a) data for the DIGITAL I/O are organized in 3 columns:CH : input / output channel numberTYPE : digital input and digital output identifiers (fixed)ACTIVE : status defined as ACTIVE

Channel selection and the ACTIVE state of the DIGITAL INPUTS can be defined by typing CHANGE. This will bring up a new display (Fig. 8.11 b)), where the changes can be made.For possible STRIKE ACTIVE selections (during CONFIGURATION) see Ch. 7.3.For the types of acceptable digital inputs and how to connect them see Fig. 4.5.

NOTE:


63

1. The STRIKE ACTIVE signal must be ACTIVE all over the strike (from the start of the strike till dropping the charge).

2. The use of DIGITAL INPUT or COMMUNICATION is recommended to signal the STRIKE ACTIVE status for SeedMaster 2. Though MOTOR CONSUMPTION (motor ON / OFF) can also be used, un-intentional stop of the motor (due for example to mains failure) will result in erroneous operation.

SEEDED input (DIN2):

It is recommended to use the AUTOMATIC SEEDING feature of SeedMaster 2, in which case there is no need for this input. Fig. 8.10 a) shows an example where automatic seeding based on supersaturation was previously configured. Possible seeding selections (during CONFIGURATION):

MANUAL SEEDAUTO SEED ON SUPERSATURATIONAUTO SEED ON DENSITYSEEDING ON DIGITAL INPUTSEEDING ON COMMAND using digital communication

Set up of DIGITAL INPUT DIN2 is required (and possible) only if SEEDING ON DIGITAL INPUT was selected during the configuration of Seeding (see: Ch. 7.5).

NOTE:The SEEDED digital input signal can be a short (momentary) one, lasting only for a few seconds, too.

CHANGE SYRUP input (DIN3 ):

This digital input can be used to inform SeedMaster 2 on the change of feed syrup.

NOTE:It is advised to use momentary digital input (pushbutton, or pulse input lasting for a few seconds).

DIGITAL OUTPUTS

There are 2 dedicated digital outputs assigned to each crystallizer. They are switching transistor types, conducting current when ON, and non-conducting when switched OFF (capacity: 0.1 A, 48 V (DC), max.). The outputs are overvoltage and overload protected (see: Ch.4.1 and Fig. 4.6).DO1and DO2 are the names of outputs dedicated to a specific task. Available free channels (DO_1…DO_4) can be assigned to anyone of these outputs.

SEED WARNING (DO1) output:

This output is intended to be used for remote �ignalling (horn, signal lamp) of the approaching seeding in order to warn the pan operator to make the seeding material (slurry) ready. It will be operated only when AUTO SEED (ON SUPERSATURATION, or ON DENSITY) was configured. This output can be used for other tasks as well. For example: if the seeding vessel is furnished with a small motor-driven stirrer, this motor can be turned on in order to homogenize the seeding slurry, and turned off automatically when seeding has been completed.

SEED VALVE (DO2) output:

This output should be used to OPEN and CLOSE the seeding valve. The Ton time can be configured (see: Ch. 7.5).

This output will be operated in all variants of seeding, that is whenMANUAL SEED,AUTO SEED ON SUPERSATURATION,AUTO SEED ON DENSITY,SEEDING ON DIGITAL INPUT orSEEDING ON COMMAND using digital communication

was configured. However, it can be left un-connected, if seeding is carried out directly by a PCS or manually by the pan-man. In these later cases, however, SeedMaster 2 has to be notified on seeding carried out by an other device (for example by using DIN2).

NOTE:Selections in column CH can be changed for both signal types, but the ACTIVE status can be changed only with DIGITAL INPUTS.


64

8.4 Set up ANALOG OUTPUT

There are 4 standard current outputs (4-20 mA, or 0-20 mA, configurable) available. These can be assignedto any one of the measured or calculated data.

SET UP -> ANALOG OUTPUT -> 1 / 0 . 1 SET UP -> AN. OUTPUT -> SUPERSAT. 1 / 0 . 1

CH . CURR. mA RANGE CLEAR AO_2 4 - 20 0 . 7 - 2 STANDARD CURRENT 4 - 20 mA

DENSITY : RANGE 0 . 7 - 2MA . SOLIDS C. : LOW LIMIT 0 . 9 CRYST. CONT . : AO_1 4 - 20 0 -60 HIGH LIMIT 1 . 1 8MEAN CR. SIZE : CHANNEL AO_2CONSISTENCY : ENGINEERING UNIT --MO. LI. PURITY :MO. LI. CONC. :MOTOR CONS. :

CHANGE BACK ACCEPTCHANGE BACK

SUPERSATUR. : :

a) b)

Fig. 8.12Figure 8.12 a) shows how to set up an output (SUPERSATURATION) channel.

To modify type CHANGE and continue the Set up as shown in Fig. 8.12 b) and Fig. 8.13.

To free an already reserved output channel select item (Fig. 8.12 a)), then select CLEAR and type CHANGE (Fig. 8.12 b)).

To add a new output select item (for example: DENSITY) and type CHANGE (Fig. 8.12 a)).Select CHANNEL and type CHANGE (Fig. 8.12 b)). Available free channels will be offered automatically. If there is no available channel, make one free first.

SET UP -> AN . OUT -> SUPERS. -> RANGE 1 / 0 . 1

MIN. MAX.

CURRENT VALUE : 0,7 2

NEW VALUE : > 0,7 1,8

CHANGE BACK

Fig. 8.13

IMPORTANT NOTE: Having completed selections or changes during any SET UP operation it is highly recommended to check if the final settings are really correct (go to SET UP -> ANALOG OUTPUT). Do not forget to close the operations by pushing the ACCEPT or ENTER key.

9 MANUAL SEEDING 65

65

9 MANUAL SEEDING

It is highly recommended to practice automatic seeding whenever possible. It will result in reproducible strikes, which, if the set-point for seeding was selected properly (see: Ch. 2.5) and the process of crystallization was also controlled well, will provide consequently high-quality product.Manual seeding can be the selected (though not recommended) mode of seeding. However, in un-common situations manual seeding of the crystallizer might be necessary. The mode of seeding (MANUAL SEED, or AUTO SEED) can and should be configured in advance during CONFIGURE -> SEEDING (see: Ch. 7.5). However, manual seeding by using the MENU soft key of the MAIN DISPLAY can be initiated any time, not influenced by the selected mode of seeding.

1 / 0. 1 MANUAL SEED 1 / 0 . 1

Menu Manual seedingDisplay PLEASE ENTER PASSWORDSet upConfiguration

ACCEPT BACK

a) b)

Fig. 9.1

When doing manual seeding the pan operator will have all the information at his disposal on the SeedMaster 2 display. Naturally, if the SUPERSATURATION reading is below 1.00, attempts to seed the crystallizer will only result in waste of seeding material (slurry) and time. Supersaturation when seeding will be documented in the Strike history.To perform manual seeding of the pan PASSWORD entry is required (Fig. 9.1 b)). The password is a 4-character number, which should be defined during configuration (see Ch. 7.8 ). The correct password will be OK-d and the actual seeding becomes possible: pushing the SEED soft-key performs the operation and confirms its completion (MANUAL SEED OK, Fig. 9.10).

MANUAL SEED 1 / 0 . 1

PASSWORD OK

MANUAL SEEDING OK

SEED BACK

Fig. 9.2NOTES: 1. Before doing MANUAL SEEDING for the first time by using SeedMaster 2 it is necessary to

SET UP a digital output to operate the seeding valve. (see Ch. 7.3). The seeding valve will be OPEN for a selected Ton time. The default value of Ton is set to 5 sec.

2. If there are 2 instruments (I1 and I2) in use always check and select the right crystallizer with the right TAG first .

3. The problem of a forgotten PASSWORD can be circumvented by configuring a new one (see Ch. 7.8).

10 DISPLAY 66

66

10 DISPLAY

10.1 MAIN DISPLAY

The MAIN DISPLAY will appear after every switch ON of SeedMaster 2. It can be accessed any time by pushing the ESCAPE key.

The MAIN DISPLAY was designed to provide all of the major information on a strike for 2 pans at the same time. The LCD is split into 2 identical halves (Instruments No.1 and No.2., or I1 and I2). Depending on the number of pans served the upper, lower or both halves can be used (Fig. 10.1). The MAIN DISPLAY is the only one where (if set up accordingly) most of the major data (10 out of the possible 11 for each) are displayed for both pans. The serial number and the TAG of the active (selected) instrument is backlit. All further operations will be carried out with the active instrument and the pan so identified. To switch between the two simply push soft key 1 or 2 on the MAIN DISPLAY.

SEEDED MAIN DISPLAY 1 / 0 . 1 SEEDED MAIN DISPLAY 1 / 0 . 1

SEED: SUPS =1 .12 AUT STRT: 141M BU SEED: SUPS =1 .12 AUT STRT: 141M BUSUPS. 1 . 1 4 LI. PUR. 9 2 .2 % SUPS. 1 . 1 4 LI. PUR. 9 2 .2 %DENS. 1 4 8 1 kg/m3 LI. CONC. 8 1 . 2 % DENS. 1 4 8 1 kg/m3 LI. CONC. 8 1 . 2 %MA. SOL. 8 8 . 7 % MO. CONS. 3 6 . 4 A MA. SOL. 8 8 . 7 % MO. CONS. 3 6 . 4 ACR. CT. 4 1 . 3 % TEMP. 6 9 . 8 C CR. CT. 4 1 . 3 % TEMP. 6 9 . 8 CCONSIST. 7 8 . 2 % LEVEL 7 7 . 5 % CONSIST. 7 8 . 2 % LEVEL 7 7 . 5 %



MENU 2 1 2 1 MENU 1

a) b)



2 MENU

c) Fig. 10.1

NOTE:If both halves of the display are used, that is if there are 2 crystallizers served, by default I1 (served by the upper half of the LCD) is selected on switch ON of SeedMaster 2.

For operations with the second crystallizer push soft key 2 first.

10 DISPLAY 67

67

DISPLAY STRUCTURE : rows 1 and 2.

Row 1:

Column 1: Information on seeding:BLANK : blank (seeding is not in close as yet).WARNSD : warning on approaching seeding (see: Ch. 7.5).SEEDED : seeding is over.

Column 2: MAIN DISPLAY

Column 3: 2 / 0.2 Instrument number over TAG of the crystallizer (see: Ch. 8.1). This area is backlit when the instrument is selected.

Column 1 Column 2 Column 3


SEED: SUPS =1 .12 AUT STRT: 21 m SC

Fig. 10.2

Row 2:

Column 1: Information on seeding:SEED : SUPS, or DENS (automatic seeding based on supersaturation or density).

Column 2: =N.NN or =XXXX : set-point for automatic seeding (supersaturation or density). AUT, or MAN : mode of seeding (automatic or manual).

STRT: XXX m : length of time (STRIKE ACTIVE TIME) of the strike in minutes.

Column 3: Strike status: WS : Wait for Start (STAND-BY mode) SC : Syrup Concentration preceding seeding GR : Graining (up to 25 % by volume crystal content) BU : Boiling up

DISPLAY STRUCTURE : data display.

There are 10 data organized in 2 columns which can be displayed for each crystallizer.

COLUMN 1:

SUPS. N.NN -- SUPERSATURATION. If the displayed data is equal to 1.00, the syrup is saturated. A less than 1.00 value means that the syrup is not saturated as yet. Real supersaturation (and crystal growth) exists only if the displayed value is larger than 1.00.

DENS. NNNN kg/m3 DENSITY. Massecuite density.MA. SOL. NN.N % MASSECUITE SOLIDS CONTENT. During syrup concentration

(SC) up to seeding it is equal to the syrup (liquor) concentration (LI. CONC.) measured by the refractometer.

CR. CT. NN.N % CRYSTAL CONTENT by volume.CONSIST. NN.N % MASSECUITE CONSISTENCY. During syrup concentration

(SC) up to seeding it is equal to syrup viscosity. Range: 0 – 100 %. COLUMN 2:

LI. PUR. NN.N % MOTHER LIQUOR PURITY. During syrup concentration (SC) up to seeding the displayed value is equal to the feed syrup puritydetermined by the local laboratory.

LI. CONC. NN.N % MOTHER LIQUOR CONCENTRATION. Concentration measured by the refractometer.

MO. CONS. NN.N kW MOTOR CONSUMPTION (kW, or A). The use of stirrer motor consumption data is not obligatory. If used, power consumptionis preferred.

TEMP. NN.N C MASSECUITE TEMPERATURE (˚C or ˚F). Temperature measured by the refractometer is preferred.

(LEVEL NN.N %) MASSECUITE LEVEL. The use of level data is not obligatory.

10 DISPLAY 68

68

(MEAN CR. SIZE N.NN mm) If LEVEL was not configured during configuration, instead of LEVEL mean crystal size will be displayed.

10.2 TREND

The MAIN DISPLAY is the starting point to access different types of information displays by selecting Displayand the RIGHT ARROW soft key (Fig. 10.2 a).There are up to 11 measured and calculated parameters which can be trended. Select Trend and enter the service by pushing the RIGHT ARROW soft key (Fig. 10.3 b)).

1 / 0 . 1 1 / 0 . 1

Menu Manual seeding Menu TrendDisplay Strike historySet up Display Standard displayConfiguration System inform.

Test data

a) b) Fig. 10.3

TRENDING A SINGLE PARAMETER

Trend of a single parameter (for example: SUPERSATURATION) is shown in Fig. 10.4 b). If LEVEL was not configured during configuration, instead of LEVEL data MEAN CR. SIZE will be displayed. Select a parameter by using the UP / DOWN ARROW and SELECT.

DISPLAY -> TREND -> TREND 1 OF 2 1 / 0 . 1 DISPLAY -> TREND -> TREND 2 OF 2 1 / 0 . 1

SUPERSAT . MO. LIQ. PUR. SUPERSAT . MO. LIQ. PUR.DENSITY 3RD INPUT DENSITY 3RD INPUTMASS. SOLIDS C. MO. LIQ. CONC. MASS. SOLIDS C. MO. LIQ. CONC.CRYSTAL CONTENT TEMPERATURE CRYSTAL CONTENT TEMPERATURECONSISTENCY LEVEL CONSISTENCY LEVEL

SUPERSATURATION : 1 .09 Act. 1 / 0 . 1

1.22

1.01

0.8

21:27 22:27 23:27 1:27

SELECT BACK SELECT ZOOM

a) b) Fig. 10.4

Scaling of the vertical axis is automatically adjusted to result in best trend resolution. The last data value is the one located in the crossing point (“cursor”) of the horizontal and vertical dashed lines. The data value (belonging to the cursor position) is numerically displayed after the parameter name. It is followed by the text “Act.”, meaning that the trend is based on actual, or current strike data.Pushing the ZOOM key will pop up Fig. 10.5 trending the same data, but using the full screen. The trend display provides additional possibilities:

The cursor can be moved and stopped along the trend by using the LEFT or RIGHT ARROW (soft keys), while the value of the parameter will be displayed numerically.

Movement of the cursor can be stopped either by a repeated push of the same, or the opposite key.Besides the current (“Act.”) trend of the selected parameter additional 3 trends of the same parameter based on data of the 3 previous strikes can be displayed by using the DOWN or UP ARROW soft keys. Strikes will be identified by the text:

10 DISPLAY 69

69

“Act. – N” where N = 1…3.

SUPERSATURATION: 1.01 Act . - 1 1 / 0 . 1

1.23

1.02

0.8

21:27 22:27 23:27 1:27

Fig. 10.5

To return to the MAIN DISPLAY push ESCAPE.

TRENDING 2 PARAMETERS

It is possible to trend 2 selected parameters at the same time, too (Fig. 10.6). Having selected the first one (Fig. 10.4 a)) a second parameter can be selected (UP / DOWN ARROW, Fig. 10.4 b)). By moving the 2 cursors at the same time (LEFT ARROW, RIGHT ARROW) data pairs belonging to the same time will be displayed numerically. The cursors can be stopped by a repeated push of the selected horizontal arrow, or by pushing the one of the opposite direction. It is also possible to view trends of the same parameter pairs based on data acquired during 3 previous strikes (DOWN ARROW, UP ARROW).

MASS. SOLIDS C.: 88 .9 % Act. 1 / 0 . 1

90

81

65

21:27 22:27 23:27 1:27

SUPERSATURATION : 1 .09 Act. 1 / 0 . 1

1.22

1.01

0.8

21:27 22:27 23:27 1:27

2 MENU

Fig. 10.6

Pushing ENTER will zoom Signal 1 to full size. If followed by keying 2 on the keyboard Signal 2 will appear in full size. Keying 1 or 2 brings back one or the other of the two signals in full size.To return to the MAIN DISPLAY push ESCAPE.

10.3 STRIKE HISTORY

It is important to provide reliable information on strikes for the technologists and pan operators right on the plant floor. The most important parameter of crystallization is supersaturation, but additional massecuite parameters might provide useful information, too.

There are two ways to obtain information on strikes monitored by SeedMaster 2.

10 DISPLAY 70

70

STRIKE HISTORY

STRIKE HISTORY (Fig. 10.7) contains condensed numerical information on supersaturation in critical points of up to 4 strikes (current or actual and 3 previous strikes). These supersaturation data are:

SEED : Supersaturation in the seeding point (not depending on the mode of seeding).MAX. : Highest supersaturation after seeding has been completed.MIN. : Lowest supersaturation after seeding has been completed.END : Supersaturation at the end of the strike.AV. : Average supersaturation from seeding to the end of strike.

DISPLAY->STRIKE HISTORY : SUPERS. 1 / 0 . 1

NO . SEED MAX. MIN. END AV.ACT. 1 . 1 2 1 . 1 6 1 . 0 7 1 . 0 9 1 . 1 3 - 1 1 . 1 2 1 . 1 6 1 . 0 8 1 . 0 8 1 . 1 1 - 2 1 . 1 2 1 . 1 5 1 . 0 7 1 . 1 0 1 . 1 5 - 3 1 . 1 2 1 . 1 4 1 . 0 7 1 . 0 9 1 . 1 3

BACK BACK

Fig. 10.7

NOTES:1. Less than 1,00 supersaturation when seeding (SEED) results in loss (dissolution) of the seed

crystals. This can lead to low crystal content when dropping the charge. If it was higher than the critical supersaturation (see Fig. 2.1), than most probably shock seeding was practiced, and / or spontaneous nucleation took place.

2. If the MAX value was larger than the critical supersaturation it most probably will be shown in inferior product quality (fines and conglomerate content, product color, see Ch. 2.5).

3. Less than 1,00 MIN or END value results in the loss of already crystallized sugar, low crystal content and / or long strike time.

4. The average value of supersaturation is inversely proportional to crystallization time. 5. The average value can be directly used to answer the appropriate question during Configuration.

IMPORTANT:STRIKE HISTORY provides a very efficient and fast method to asses the level of control (manual or automatic) exercised.

DETAILED STRIKE HISTORY

Detailed strike history, that is in-depth information on up to 11 massecuite parameters and measured data acquired during the last 4 strikes (current, or actual and 3 previous ones) can be obtained by using the TREND-s, which are automatically prepared by SeedMaster 2 (see Ch. 10.2).

WHEN USED EFFECTIVELY, STRIKE HISTORY TOOLS CAN HELP TO VASTLY IMPROVE CRYSTALLIZATION PRACTICE. If a PCS is in use, strike history data can be sent to it for further use (seeCh. 11).

10.4 STANDARD DISPLAY

The STANDARD DISPLAY (Fig. 10.8) can be used to display 2 (per crystallizer) preferred parameters of the massecuite with large characters. The 2 parameters can be selected from those available (maximum 11) for this type of display during the SET UP -> DISPLAY operations (see Ch. 8.1).

10 DISPLAY 71

71

WARNSD STANDARD DISPLAY P1:95.2% 1 / 0 . 1

SUPERSATURATION : MASS. SOLIDS C.: %

0.81 72.8SEEDED STANDARD DISPLAY P2:92.32% 2 / 0 . 2

SUPERSATURATION : MASS. DENSITY: kg/m3

1.12 1482 BACK

Fig. 10.8

This is a display – only presentation of the selected data. Information on seeding and on the purity of the feed syrup currently in use is also presented. The only operation (BACK) results in the return to the previous step on the selection tree.

10.5 SYSTEM INFORMATION

SYSTEM INFORMATION provides a brief summary on data inputs and outputs and on the selected mode of seeding (Fig. 10.9).

WARNSD SYSTEM INFORMATION 1 / 0 . 1

INPUT OUTPUT SEEDINGCONC . : SER . SER . : 0 AUTO SUPS .TEMP . : SER . 0 - 20 : 0 SETP . : 1 . 12MOTOR: 4 - 20 4 - 20 : 2

SYSTEM INFORMATION 2 / 0 . 2

INPUT OUTPUT SEEDINGCONC . : SER. SER . : 0TEMP . : SER. 0 - 20 : 0 COMM.DENS.: COMM. 4 - 20 : 2

BACK

Fig. 10.9The 1st row shows :1. current information on seeding :

BLANK : blank (no seeding in close as yet)WARNSD : warning on approaching seeding (see Ch. 7.5)SEEDED : seeding is over.

2. INSTRUMENT NO. over TAG.

The INPUT column lists the types of inputs configured for the CONCENTRATION, TEMPERATURE and THIRD INPUT data. The last one is identified by the actual name of the type of input (MOTOR, DENS., MA. SOL., CR. CONT. meaning motor consumption, density, massecuite solids content and crystal content determined by the laboratory) selected during configuration.Possibilities:

SER. : Data input directly from the refractometer using communication (COMX port).4 – 20 : Standard current, mA.

0 – 20 Standard current, mAMAN : Laboratory crystal content data (see Ch. 7.3.3), manual entry.COMM. : Data transfer via digital communication (COMX or Ethernet).

10 DISPLAY 72

72

The OUTPUT column lists the number of serial (COMX.), digital communication (COMM.) and Standard current (0-20 mA and 4-20 mA) outputs.The SEEDING column provides information on the type of seeding selected (MANUAL, AUTO SUPS., or AUTO DENS. With the selected SET POINT or commanded via COMMUNICATION).

10.6 TEST DATA

The TEST display is a tool to check the operation of SeedMaster 2 hardware and some of its software.

Analog input

1 / 0. 1 1 / 0 . 1

Menu Trend Menu Analog inputStrike history Analog output

Display Standard display Display Digital I/OSystem information COMX portsTest Test Other data

EventsModbus reg.

a) b)

Fig. 10.10

DISPLAY -> TEST -> ANALOG INPUT

ANALOG INPUTSAI_1 : 12.4 mA AI_5 : 18.9 mA AI_2 : 0 mA AI_6 : 0 mA AI_3 : 0 mA AI_7 : 0 mA AI_4 : 0 mA AI_8 : 0 mA

BACK

Fig. 10.11

In Fig. 10.11 current (actual) analog (standard current) inputs from 2 transmitters (for example: 2 motor consumption transmitters) are shown.

NOTE:SeedMaster 2 has 8 analog inputs which can serve 2 instruments. If 2 pans are served, it is recommended to reserve channels AI_1…AI_4 for instrument I1 and inputs AI_5…AI_8 for instrument I2, respectively, which makes instrument identification and eventual addition of further inputs easier.

10 DISPLAY 73

73

Analog output

Actual standard current output can be checked using this feature (Fig. 10.12).

DISPLAY -> TEST -> ANALOG OUTPUT

ANALOG OUTPUTSAO_1 : 7 . 2500 mA AO_2 : 14 . 2000 mA AO_3 : 4 . 0000 mA AO_4 : 4 . 0000 mA

BACK

Fig. 10.12

Digital I / O

Status information on digital I / O-s :

DISPLAY -> TEST -> DIGITAL I / O

DIGITAL INPUTS ( DI_1…DI_8 ) : 1 2 3 4 5 6 7 8 1 0 0 0 0 0 0 0

DIGITAL OUTPUTS ( DO_1…DO_4 ) : 1 2 3 4 1 0 0 0

BACK

Fig. 10.13

COMX port

DISPLAY -> TEST -> COMX port 1 / 0 . 1

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

ERRORS: 0 0Concentration: : 3 Temperature : 3

BACK RESET

Fig. 10.14

10 DISPLAY 74

74

Display -> Test -> COMX port is used to test serial data input (concentration and temperature data from a PR-01-S refractometer) during the ACTIVE MODE of operation (see Ch. 3.3). Whenever concentration or temperature data are outside their normal ranges the data will be replaced by the appropriate RANGE HIGH, or LOW limit values and the error counters Concentration and / or Temperature will be incremented. The contents of the 2 counters can be cleared by using RESET.

NOTE:Concentration or temperature data are regarded normal when they are within ranges characteristic of the usual active crystallization procedures (see Ch. 6.2). However, they can be outside their respective normal ranges for example after dropping the charge or during cleaning of the pans (concentration or temperature can be too high). This kind of data monitoring is therefore only active when the strike is ACTIVE, too.

Other data

DISPLAY -> TEST -> OTHER DATA

CRYST. PARAMETER : 0 , 0 2 7 2 8 5TIME OF CRYST. (M) : 9 8 min AVERAGE SUPERS. : 1 , 1 2

BACK

Fig. 10.13

CRYST. PARAMETER : It is used in crystal growth calculations. It is automatically calculated (re-calculated) after completing or modifying configuration.

TIME OF CRYST. (M) : Time measured from seeding till the end of strike (minutes).AVERAGE SUPERS. : Average supersaturation from seeding till the end of strike.

NOTE:After the first complete strike, TIME OF CRYSTALLIZATION and AVERAGE SUPERSATURATION data can be used to refine the data given previously to the related questions during configuration.

Events

Events are categorised as non-acknowledged, acknowledged and historytypes. All three have their dedicated screens with exact date and time data, instrument identification number (1 / or 2 /), name of the signal and event type (RANGE EXCURSION, HIGH / LOW ALARM). Acknowledged events are cleared from the list of non-acknowledged ones. The Events History list contains all events until they fill available memory, when the oldest events will be overwritten with the most recent ones.

10 DISPLAY 75

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1 / 0 . 1 TEST->EVENTS->NON-ACKNOWLEDGED 1 / 0 . 1

Menu Non-acknowledged YEAR:2005 MONTH: 07Acknowledged DAY: 29 HOUR: 14

Display History HH:MM EVENTS

14:16 1 / CR. CONT. LAB RANGE E.Test 14:22 1 / MA. SOL. HIGH AL.

14:25 2 / MO. CONS. LOW AL.

Events

BACK ACKN.

a) b)

TEST->EVENTS->HÍSTORY 1 / 0 . 1

EVENTS' YEAR:2005 MONTH: 07HISTORY DAY: 29 HOUR: 14HH:MM EVENTS

13:02 2 / LEVEL RANGE E.13:02 2 / LEVEL RANGE E. OK14:08 1 / LI. CONC. HIGH AL.14:11 1 / LI. CONC. HIGH AL. OK14:15 1 / DENS. OUT HIGH AL.

14:16 1 / CR. CONT. LAB RANGE E.14:16 1 / CR. CONT. LAB RANGE E. OK14:15 1 / DENS. OUT HIGH AL. OK14:22 1 / MA. SOL. HIGH AL.

14:25 2 / MO. CONS. LOW AL. ACKN. BACK

c)

Fig. 10.14MODBUS registers

TEST -> MODBUS REG. 1 / 0 . 1

Base address 0Reg. addr. Type Value

0 float 0 . 000002 float 0 . 000004 float 0 . 000006 float 0 . 00000

8 float 0 . 0000010 float 0 . 0000012 float 0 . 0000014 float 94 . 669916 float 0 . 1780018 float 0 . 8280020 float - 2 . 10000

CHANGE BACK ACCEPT

Fig. 10.15

Communication when using the MODBUS protocol can be checked. Register addresses, type of data (floating, word) and data values are displayed. Base address can be changed.

NOTE:For communication details when using the MODBUS protocol see Chapter 11.

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11 COMMUNICATION

11.1 ETHERNET COMMUNICATION

It is possible to use the Ethernet port of SeedMaster 2 to implement two-way communication with a computer, a Process Control System (PCS), or with any other intelligent device having an Ethernet interface with TCP / IP protocol support.There are two ways to use Ethernet communication with SeedMaster 2:

direct communication with a computer (for example: with a PC), and by integrating SeedMaster 2 in a LAN (Local Area Network) using

a HUB, a SWITCH or ROUTER,a WLAN (wireless network WiFi), oroptical cables (FDDI, Fiber Ethernet).

Data transmission using the Ethernet

Measured and calculated data, parameters and digital (ON/OFF) data can be transmitted in both directions between SeedMaster 2 and a computer, or a PCS.Communication is based on the use of the MODBUS TCP / IP protocol. This is a client/server type communication among devices connected in an Ethernet TCP/IP network. It is actually the network version of the MODICON MODBUS RTU protocol.A TCP:502 port is reserved for the communication. Playing the role of a MODBUS server SeedMaster 2 is waiting for requests from clients (PC, PCS, SCADA). Data to be transmitted are stored in Register Tables in the server. The MODBUS client asks for the transmission of these data. The communication structure is of the request / answer type, that is the client asks for data from the server which responds by sending them.A detailed description of the protocol can be found in:

Modbus Messaging Implementation Guide V1 0a.pdf

and in

Modbus Application Protocol V1 1a.pdf

Cable requirements and connection

Cable specification

SeedMaster 2 uses the standard 10/100BASE-T Cat 5E twisted pair cable with RJ45 type connector. The maximum length of the cable is 100 m.

Direct connection to a computer: use a Cat E cross-over patch cable.Using a wall type connector : use a Cat E straight-through patch cable.Using other network devices : when using a HUB, SWITCH, ROUTER or WLAN access

point read the instructions for their correct connection.

If the application requires larger than 100 m cable length, or there is considerable electromagnetic interference in the area use FDDI (Fiber Distributed Data Interface) connection with a media converter.

Connecting the Ethernet cable

To connect the cable to SeedMaster 2 open the front cover of the enclosure, loosen the front panel screw and swing the panel open. The RJ45 type Ethernet connector is marked and can be accessed easily (Fig. 4.10). Insert the cable in one of the cable glands and plug the cable into the connector. Connect the other end of the cable to the appropriate connector of the computer or other device (HUB, SWITCH, ROUTER or WLAN access point).

WARNING:It is advised to do the connection with mains power switched off.

NOTE:SeedMaster 2 can be used with networks operating at 10 or 100 Mbit/sec speed of transmission. Speed detection and adjustment is automatic.

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Connection settings

Setting the IP address of SeedMaster 2

SeedMaster 2 uses the Ipv4 protocol for Ethernet communication, which requires setting of its IP address.The factory setting of the IP address is: 192.168.0.100The subnet mask : 255.255.255.0

If the device is connected to a single computer there is no need to change the IP address. If it is connected to a local network (LAN), then ask the system administrator to assign an address for SeedMaster 2.To change the IP address select:

Menu -> Configuration -> Interface -> Ethernet -> SeedMaster 2 (see Ch. 7.7.2 and Fig. 7.13).

SeedMaster 2 can operate as a DHCP (Dynamic Host Control Protocol) server, too. In this case it is able to supply IP address(es) to the computer(s) connected to it automatically. This mode of operation can be configured by selecting:

Menu -> Configuration -> Interface -> Ethernet -> SeedMaster 2 : DHCP SERVER = YES.Consult your network administrator about the use of this mode of operation.

Setting the IP address of the computer

The description here supposes the use of the Windows XP operating system, but it is valid for all computers running a Microsoft operating system. Consult the manual of the operating system in use.

NOTE:Changing of network settings requires system administrator level authorization.

Steps to set the IP address:1. Start -> Control Panel ->Network and Dial- up Connections2. Net Connections3. Local Connection4. Properties5. TCP / IP protocol -> Properties

The IP address can be entered or changed in the displayed window. There are two possible ways to do it: Obtain an IP address automatically.

In this case SeedMaster 2 should be operating as a DHCP server and must be configured accordingly:

Menu -> Configuration -> Interface -> Ethernet -> SeedMaster 2 : DHCP SERVER = YES There is no need to set any IP address in the computer because it will be assigned

automatically by SeedMaster 2.

Use the following IP address.

Data entry windows :IP ADRESS : 192.168.0.102NETWORK MASK : 255.255.255.0GATEWAY : 192.168.0.1

When finished, connect the computer and SeedMaster 2 with a cross-over patch cable.

NOTES:

1. The computer and SeedMaster 2 must be operating on the same subnet. This means that in their IP addresses the first 3 numbers separated by points must be identical in both devices, while the fourth ones must be different, but not equal to 0 or 255. 2. The Network mask must be identical in both devices.

Testing the connection

The RJ45 type connector of SeedMaster 2 has two diagnostic LED-s. The orange LED indicates a working physical connection, while the green one indicates data traffic in the cable.To test the connection switch ON SeedMaster 2 first and check if the orange LED is lit, indicating that the cable was plugged at both ends, the two devices are powered and the cable is of the required type.

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There is a ping command available in the Windows operating systems which can be used to test the connection. This command sends small packages of data through the Ethernet network, which have to be answered by the receiving device.

To start ping select Start -> Command Prompt, enter cmd.exe and OK, thenwrite ping and the IP address and OK in the opening window, for example: ping 192.168.0.101 OK

If the connection is OK, then SeedMaster 2 will answer all requests and the number of lost data packets in the Ping statistics will be zero. If there are errors during transmission error messages will be displayed, for example: Destination host unreachable.

Troubleshooting

If a ping command results in an error message in the computer, check if

1. SeedMaster 2 is switched ON,2. the LED-s of the RJ45 type connector are lit, if not, check if

both ends of the cable are connected, the cable is of the required type (Cat E cross-over patch cable).

3. If the orange LED is lit the physical connection is OK.4. If the green LED is not flashing during ping, check the IP address setting.5. If SeedMaster 2 is not directly connected to a computer, but via a local network, there may be a

routing problem. Consult your network administrator.

MODBUS TCP / IP as implemented in SeedMaster 2

SeedMaster 2 operates as a SLAVE communication station. This means that data requests are obeyed if the requested information (the registers containing it) exists.SeedMaster 2 obeys MODBUS/TCP Class 1 type requests, that is:

Reading a Bloc of Registers (command code: 3)Writing a Bloc of Registers (command code :16 (decimal))

Simply put: only reading and writing of Modbus registers is implemented.

Data available for transmission complete with their register addresses are collected in a table (see: MODBUS Register Table).

MODBUS commands

READ MODBUS REGISTER (Command 3)

Query:

A F RAH RAL RNH RNL

Response:

A F BN D1 … DN

WRITE MODBUS REGISTER (Command 16 (decimal))

Query:

A F RAH RAL RNH RNL BN D1 … DN

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Response:

A F RAH RAL RNH RNL

Notation:

A SeedMaster 2 address (station address)F command codeRAH, RAL base address of MODBUS registers,

RAH: high, RAL: low address byteRNH, RNL number of MODBUS registers,

RNH: high, RNL: low byte of the numberBN number of data bytes sent (0…255)D1…Dn data bytes, n=number of registers*2,

high byte firstLength of a MODBUS register: 2 bytes

The MODBUS /TCP messages consist of 3 parts:

Header (7 bytes) Command code (1 byte) Data bytes

Header structure:

Field name Length Description Client Server

Transaction ID 2 bytes MODBUS Set by the Copies the ID transaction Client set by the Clientidentity in the response

Protocol ID 2 bytes 0 = MODBUS Set by the Copies the ID Client set by the Client

in the response

Length 2 bytes Number of the Set by the Set by thebytes which Client Serverfollow (Request) (Response)

Device ID 1 byte Identity of the Set by the Copies the ID serial line, or Client set by the ClientEthernet device in the response

Transmission example:

The numbers shown are hexadecimal without spaces (the spaces inserted below are only to make reading easier).

Client’s request to READ REGISTERS:

25 00 00 00 00 06 15 03 00 00 00 0C complete message25 00 00 00 00 06 15 header, SeedMaster 2 ID = 15(hex) = 21 (decimal) 03 command code (READ) 00 00 register base address 00 0C number of registers = 0C (hex) = 12 (decimal)

6 bytes

SeedMaster 2 response:

25 00 00 00 00 1B 15 03 18 6B 85 42 9D 85 1F 42 8B 97 ED 44 B7 6E CC 42 AC 00 00 00 00 00 00 00 00

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25 00 00 00 00 1B 15 header, ID = 15 (hex) 03 command code (READ)

18 number of bytes = 18 (hex) = 24 (dec) 6B 85 42 9D 85 1F data (24 (dec) bytes) 42 8B 97 ED 44 B7

1B (hex) = 27 (dec) 6E CC 42 AC 00 00 bytes follow 00 00 00 00 00 00

18 (hex) bytes

Client’s request to WRITE REGISTERS:

0F 00 00 00 00 0E 15 10 00 80 04 08 80 00 42 9E 8A 3D 42 8D complete message0F 00 00 00 00 0E 15 header, SeedMaster 2 ID = 15 10 command code (WRITE) 00 80 register base address 04 number of registers 08 number of bytes

80 00 42 9E 8A 3D 42 8D dataThe Client requests writing the 8 data bytes in the registers of SeedMaster 2 with MODBUS address 15 (hex) starting from base address 0080 (hex).

SeedMaster 2 will acknowledge the request with the following message:

0F 00 00 00 00 06 15 10 00 80 00 04 complete message0F 00 00 00 00 06 15 header, SeedMaster 2 ID = 15 10 command code (WRITE) 00 80 register base address 00 04 number of registers

Numbers in the MODBUS registers

Storage of data in the MODBUS registers: Hbyte Lbyte

WORD data

This type of data is stored in 2 bytes (16 bits). There is no sign stored and the range is 0 – 65535.

MODBUS REGISTERHIGH byte LOW byteMost Significant Bit Least Significant Bit15 0

FLOATING POINT data

Floating point data in SeedMaster 2 comply with the IEEE 754 / 1985 SHORT REAL (SINGLE PRECISION) format specification. The number consists of 3 parts:

sign, exponent and mantissa,

which are stored in 4 bytes. Consequently, storage of floating point numbers requires 2 MODBUS registers.

High address MODBUS register Low address MODBUS registerHigh byte Low byte High byte Low byte S Exponent Mantissa31 30 23 22 0

The value of the sign bit S is 0, if the number is positive, and 1, if it is negative. Due to the fact that the numbers do not use the 2-s complement notation, + 0 and – 0 are also represented.The Mantissa is stored in normalized form which means that:

bit 22 = 2-1

, bit 21 = 2-2

, … , and bit 0 = 2-23

.

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The Exponent field contains the sum of the actual exponent and a bias. Bias is used to make the number in the Exponent field always positive. The value of Bias is always 127. The largest and the smallest value of the exponent is used for error signalization, therefore the range of the exponent is – 127…+ 127.

Floating point number = (-1)*S*(1+Bit22*2-1

+Bit21*2-2

+…+Bit0*2-23

) *2Exponent-127

11.2 MODBUS protocol using one of the COMX ports

SeedMaster 2 is able to exchange different types of data by using one of the serial COMX ports of the device. The applied protocol is the MODBUS protocol. Both the MODBUS RTU and the MODBUS ASCII are implemented in SeedMaster 2.

SeedMaster 2 operates as a SLAVE device/station. The MASTER, typically a PC sends requests to a slave station and the addressed SeedMaster 2 answers if the required information (registers) are available.The accessible data are listed in the SeedMaster 2 register set table (see: SeedMaster 2 register set, page 85).

A subset of the MODBUS protocol is implemented:Command 3: Read Multiple RegistersCommand 16: Write Multiple Registers

Important note:The slave address parameter – together with the parameters of the serial line and the protocol- has to be given / defined before the installation of SeedMaster 2.

Remark: for more details please use “Modicon Modbus Protocol Reference Guide PI MBUS 300 Rev. J”.

The COMX ports of SeedMaster 2There are 3 COM ports (COM1 to COM3, galvanically isolated) in the SeedMaster 2 device.It is recommended to use COM1 for communication with a PCS or PC.COM2 and COM3 can be used for connecting 1 or 2 refractometers to SeedMaster 2.

Setting the protocol parametersThe parameters of the serial line and the protocol have to be defined before the installation of SeedMaster 2(see Ch. 7.7.1 for details).

The physical type of the serial line is user selectable: RS232 RS485 RS422 point to point RS422 multidrop

The serial line parameters:Baud rate: 1200…38400

Data format : RTU modeBits per Byte: 1 start bit

8 data bits, least significant bit sent first 1 bit for even/odd parity; no parity bit for not defined parity 1 stop bit if parity is used; 2 stop bits if parity is not defined

Data format : ASCII mode Bits per Byte: 1 start bit

7 data bits, least significant bit sent first 1 bit for even/odd parity; no parity bit for not defined parity 1 stop bit if parity is used; 2 stop bits if parity is not defined

Users can configure SeedMaster 2 for Even or Odd Parity checking or for No Parity checking (only when using ASCII mode)For example if the eight data bits are 1100 0101, the total quantity of 1 bits in the frame is four. If Even Parity is used, the frame’s parity bit will be 0, making the total quantity of 1 bits still an even number (four). If Odd Parity is used the parity bit will be 1, making an odd quantity (five).

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ASCII Framing

In ASCII mode messages start with a ‘colon’ ( : ) , and end with a ‘carriage return – line feed’ (CRLF) pair.Coding System: One hexadecimal character contained in each ASCII character of the message, i.e. 1 byte data transmission requires transmission of 2 characters. The allowable characters transmitted for all other fields are hexadecimal 0–9, A–F.Networked devices monitor the network bus continuously for the ‘colon’ character.When one is received each device decodes the next field (the address field) to find out if it was its own device address.Intervals of up to one second can elapse between characters within the message.If a greater interval occurs the receiving device assumes an error has occurred.

A typical message frame is shown below.

START: : (colon, 3A hex) ADDRESS (device) : 2 hex charactersFUNCTION code : 2 hex characters codeDATA : 2…2N charactersLRC CHECK : 2 characters END : CRLF (0D and 0A hex)LRC : is the Error Check Field, Longitudinal Redundancy Check

(LRC) is used.LRC Checking

Messages include an error checking field that is based on the Longitudinal Redundancy Check (LRC) method. The LRC field checks the contents of the message exclusive of the colon start and CRLF end pair. It is applied regardless of any parity check method used for the individual characters of the message. The LRC field is one byte containing an 8 bit binary value. The LRC value is calculated by the transmitting devicewhich appends the LRC to the message. The receiving device calculates an LRC during receipt of the message and compares the calculated value to the actual value it received in the LRC field. If the two values are not equal an error will result. The LRC is calculated by adding together successive 8 bit bytes of the message discarding any carries, and then two’s complementing the result. It is performed on the ASCII message field contents excluding the colon character that starts the message, and excluding the CRLF pair at the end of the message.

RTU Framing

In RTU mode messages start with a silent interval of at least 3.5 character times. The first field then transmitted is the device address. The data transmitted are bytes represented as 2 hexadecimal characters. The allowable characters transmitted for all fields are hexadecimal 0-9 and A-F.Networked devices monitor the network bus continuously including the silent intervals, too. When the first field (the address field) was received, each device decodes it to find out if it was its own device address. Following the last transmitted character a similar interval of at least 3.5 character times marks the end of the message. The final CRC field has to be valid for a successful receive / transmit operation.

A typical message frame is shown below

DEVICE ADDRESS 1 byte hexadecimal address FUNCTION CODE 1 byte hexadecimal code DATA FIELD N bytes hexadecimal dataCRC CHECK 2 bytes hexadecimal CRC

CRC is the Error Check Field, 2 bytes. Cyclical Redundancy Check (CRC) is used.

CRC checking

In RTU mode messages include an error checking field that is based on a Cyclical Redundancy Check (CRC) method. The CRC field checks the contents of the entire message. It is applied regardless of any parity checkmethod used for the individual characters of the message. Messages include a 2 bytes long CRC field.

CRC has to be calculated on the message except the CRC itself.

The polynomial used for calculation: A001H.

The next steps perform the CRC calculations:

1. Fill the CRC word with FFFF (hex) start value.

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2. XOR CRC high with the 1st

data byte, the result remains in the CRC word.

3. Shift CRC 1 bit right.

4. If the most significant bit of the CRC was 0 before the shift, the next step is step 3 (go to step 3).

5. If the least significant bit of the CRC was 1 before the shift (1 was shifted out) then XOR CRC and the CRC calculation polynomial A001 (hex), the result remains in the CRC word.

6. Repeat steps 3 & 4 until 8 shifts.

7. XOR CRC and the next data byte, the result remains in the CRC word.

8. Repeat 3-7 steps with all data bytes.

9. The result is the CRC code to be sent or verified.

The implemented MODBUS commands:

Read multiple MODBUS registers command, function code : 03(03h):

Query:

A F RAH RAL RNH RNL CH CL

Response:

A F BN D1 … DN CH CL

Write multiple MODBUS registers command, function code : 16 (10h):

Query:

A F RAH

RAL

RNH

RNL

BN D1 … CH CL

Response:

A F RAH RAL RNH RNL CH CL

where

A – slave address

F – function code

RAH, RAL – starting address of the MODBUS registers, order: high byte first

RNH, RNL – number of the MODBUS registers, order: high byte first

BN – number of the data bytes sent (0..255)

D1….Dn – n data bytes, n=BN*2, order: high byte first

CH, CL – CRC control code, order: high byte first

Examples

Function code: 3 (read), RTU mode

Read the first 32 data (64 registers, i. e. 128 bytes) from the „read data” table of the 1st

Crystallizer ofSeedMaster 2 having the station address 17 (11h):

Query:

Slaveaddress

Functioncode

1st register

address(high byte)

1st register

address(low byte)

No of registers

(high byte)

No of registers (low byte)

CRC code

(2 bytes)

11h 03h 00h 00h 00h 40h CRC

Response:

Slave address

Functioncode

No of the bytes sent

Data bytes CRC(2 bytes)

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(1byte)11h 03h 80h 128 bytes CRC

Function code: 16 (write), RTU mode

Write the first 32 data (64 registers, i. e. 128 bytes) into the „write data” table of the 2nd

Crystallizer of SeedMaster 2 having station address 17 (11h):

Query:

Slave address

Functioncode

1st register

address(high byte)

1st register

address(low byte)

No of registers

(high byte)

No of registers

(low byte)

No of bytes

(1 byte)

Data bytes CRC code

(2 bytes)

11h 10h 00h 180h 00h 40h 80h 128 bytes CRC

Response:

Slave address

Functioncode

1st register

address(high byte)

1st register

address(low byte)

No of registers

(high byte)

No of registers (low byte)

CRC code

(2 bytes)

11h 10h 00h 00h 00h 40h CRC

Remark: Byte order on the MODBUS communication: High byte first, Low byte second.

11.3 Data types used in the MODBUS registers

A single MODBUS register has 2 bytes for data storage.

Byte (8 bit unsigned integer)

Low or high byte of a MODBUS register, value range 0…255 (00h…FFh)

Word (16 bit unsigned integer)

One MODBUS register can be a word type variable, value range 0 .. 65535 (0000h … FFFFh)

Real (FLOAT)

All of the SeedMaster 2 data / variables are 4 byte real type.

The real values have the standard IEEE 754/1985 SHORT REAL (SINGLE PRECISION) 4 byte format and are stored in two consecutive registers.

The value range is +/-(8.43*10-37

– 3.4*10+38

), the resolution is 7 decimals.

Measured and calculated data of SeedMaster 2 are of the 4 byte real, IEEE standard type.This way a SeedMaster 2 real (float) data can be accessed by reading 2 registers.

Data on the serial line reading a measured value:

First register: (reg1) Second register: (reg2)High byte (reg1_Hi) Low byte (reg1_Lo) High byte (reg2_Hi) low byte (reg2_Lo)

The received bytes have to be arranged as shown below to form a real number:

MSB LSBreg2_Hi reg2_Lo reg1_Hi reg1_Lo

The number format:

reg2_Hi reg2_Lo reg1_Hi reg1_Lo

Exponent (8bit) Mantissa (23 bit)

S: Bit31 sign of the number, 0 if the real number is positive.

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Exponent: Bit30..Bit23 the value is the exponent of the number+127. The range is -126…127

Mantissa : Bit22..Bit0 normalized, highest bit means ½ , the next one ¼ and so on.

Value of the real number can be calculated using the formula below:

Value= (-1)*S * (1+Bit22*2-1+Bit21*2

-2+Bit20*2-3+…...+Bit0*2

-23) *2Exponent-127

Remark: The -0 is „not a number”.

11.4 Register set

SeedMaster 2 can handle 2 crystallizers simultaneously.

There are dedicated “read” and “write” data tables for both crystallizers, using two identical register sets forcommunication. One table (read only, or RO) stores measured and calculated data. The other table (read and write, RW) serves for writing parameters or to input data into SeedMaster 2.

The register sets are identical, so the addresses can be calculated as follows:

Address= base address + offset address

SeedMaster 2 register set

Base addresses (decimal)

Type Name

0 Crystallizer 1 Read only O1 RO

128 Crystallizer 1 Read-Write O1 RW

256 Crystallizer 2 Read only O2 RO

384 Crystallizer 2 Read-Write O2 RW

Offset address (decimal)

Register name Type O1 RO O1 RW O2 RO O2 RW

0 Concentration (syrup, m. l.) Real 0 128 256 384

2 Temperature Real 2 130 258 386

4 Massecuite density Real 4 132 260 388

6 Massecuite solids content Real 6 134 262 390

8 Motor consumption Real 8 136 264 392

10 Crystal content (laboratory) Real 10 138 266 394

12 Level Real 12 140 268 396

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14 Mean crystal size Real 14 142 270 398

16 Syrup „m” parameter Real 16 144 272 400

18 Syrup „b” parameter Real 18 146 274 402

20 Syrup „c” parameter Real 20 148 276 404

22 Real 22 150 278 406

24 Pan max. level Real 24 152 280 408

26 Motor cut-off consumption Real 26 154 282 410

28 Motor cons. (Phase 1 end) Real 28 156 284 412

30 Motor cons. (strike end) Real 30 158 286 414

32 Motor constant Real 32 160 288 416

34 Crystal cont. (Phase 1 end) Real 34 162 290 418

36 Conc. (Refr., Phase 1 end) Real 36 164 292 420

38 Conc. (Refr., strike end) Real 38 166 294 422

40 Temp. (Refr., Phase 1 end) Real 40 168 296 424

42 Temp. (Refr., strike end) Real 42 170 298 426

44 Crystal cont. (lab., seeding) Real 44 172 300 428

46 Crystal cont. (lab., str. End) Real 46 174 302 430

48 Seed crystal size Real 48 176 304 432

50 Product crystal size Real 50 178 306 434

52 Length of crystal time Real 52 180 308 436

54 Average supersaturation Real 54 182 310 438

56 Supersaturation Real 56 184 312 440

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58 Crystal content Real 58 186 314 442

60 Consistency Real 60 188 316 444

62 Mother liq. Purity Real 62 190 318 446

64 Strike Act SEED Real 64 192 320 448

66 MIN Real 66 194 322 450

68 MAX Real 68 196 324 452

70 END Real 70 198 326 454

72 Strike Act-1 SEED Real 72 200 328 456

74 MIN Real 74 202 330 458

76 MAX Real 76 204 332 460

78 END Real 78 206 334 462


82 MIN Real 82 210 338 466

84 MAX Real 84 212 340 468

86 END Real 86 214 342 470


90 MIN Real 90 218 346 474

92 MAX Real 92 220 348 476

94 END Real 94 222 350 478

96 Warn seed value (supersat.) Real 96 224 352 480

98 Warn seed value (density) Real 98 226 354 482

100 Set-point (seeding, supers.) Real 100 228 356 484

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102 Set-point (seeding, density) Real 102 230 358 486

104 Strike active (start of str.) WORD 104 232 360 488

105 Seed warning WORD 105 233 361 489

106 Seeding WORD 106 234 362 490

107Type of seed warning (supers./density)

WORD 107 235 363 491

108Type of seeding set-point (supers./density)

WORD 108 236 364 492

109 Level (measured) WORD 109 237 365 493

110 Purity No.1. REAL 110 238 366 494

112 Purity No.2. REAL 112 240 368 496

114 Purity No.3. REAL 114 242 370 498

116 Level L1 REAL 116 244 372 500

118 Level L2 REAL 118 246 374 502

120 Level (maximal) REAL 120 248 376 504

NOTES:1. WORD content (command) to START STRIKE : 12. WORD content (command) to STOP STRIKE : 03. WORD content (command) to SEED : 14. WORD content (command) to de-activate SEED : 0

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12 APPENDIX 1 : PROCEDURE TO EVALUATE THE “m”, “b” AND “c” COEFFICIENTS OF THE WIKLUND-VAVRINECZ SATURATION FUNCTION.

12.1 Introducing the solubility coefficient

By analyzing a large amount of data on sugar solubility in beat sugar molasses collected by different researchers, Wiklund and Vavrinecz developed an equation (saturation function) for the calculation of the solubility (or saturation) coefficient.The solubility coefficient is defined by the ratio

Z’C = ------ Z

where:Z’ : sugar in solution in the impure sugar solution at saturation, g/100 g water.Z : sugar in solution at saturation in the pure sugar solution at the same temperature, g/100 g

water.

The solubility coefficient can be calculated by the saturation function as

Fsat = C = m.NS/W + b + (1-b). EXP(c.NS/W) (Eq. 2)where:

NS/W : nonsugar to water ratiom, b, c : syrup quality parameters to be determined by the local laboratory.

NOTE :The syrup quality parameters depend only on the composition of the nonsugars. They do not depend on the temperature or on the amount of nonsugars.

Solubility coefficient versus non-sugar to water (N/W) ratio

SA TURATION COEFFIC IENT V ERSUS NONSUGAR TO WAT ER RA T IO (NS/W)(m = 0.194; b = 0.771; c = -1.8)

0,92

0,94

0,96

0,98

1

1,02

1,04

1,06

1,08

1,1

1,12

0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8

NONSUGAR TO WAT ER RA T IO (NS/W)

Fig. A.1

Fig. A.1 shows the saturation function with parameters typical for beat sugar molasses.

It can be seen (and proved, too), that above some NS/W ratio (in this case about 1.2) the function can be represented by a straight line with a slope equal to “m”. Below this NS/W value the function is more and more represented by the exponential part.

One of the several possible ways to determine the local syrup quality parameters in the laboratory is described below.

12 APPENDECES 90

90

12.2 Determining the local syrup parameters

12.2.1 Sample preparation for the saturation test

A) Take 7-10 samples 100 g each from the same low-purity final molasses (green syrup) and determine concentration, sugar content and purity data in the lab. Calculate non-sugar and water content, too. Put the samples in vessels which can be well sealed later on in order to prevent evaporation or leakage.

EXAMPLE :

ORIGINAL SAMPLES :

SOL (g) S (g) Q (%) NS (g) W (g) Gsample (g)

1 83,22 51,37 61,73 31,85 16,78 100,00

2 83,22 51,37 61,73 31,85 16,78 100,00

3 83,22 51,37 61,73 31,85 16,78 100,00

4 83,22 51,37 61,73 31,85 16,78 100,00

5 83,22 51,37 61,73 31,85 16,78 100,00

6 83,22 51,37 61,73 31,85 16,78 100,00

7 83,22 51,37 61,73 31,85 16,78 100,00

where :SOL (%, g) : solids content (concentration)S (%, g) : sugar contentQ (%) : purity = 100.S/SOL

NS (g) : non-sugar content = SOL - S W (g) : water content = Gsample - SOL

B) Calculate the non-sugar to water ratio (NS/W) and enter it for sample No.1, which from now on will represent the original sample with its original NS/W ratio. Select (NS/W)* values which will result in well distributed data in the complete range from (NS/W)* = 0 to the original one. Using the selected (NS/W)* and the original water content (W) calculate new water content (W*) and water to add (Wadd) data for samples No.2-No.7.NOTE : when (NS/W)* = 0, the saturation coefficient is always equal to 1.0.

SOL.(100 - Q)NS/W = ---------------------- 100.(100 - SOL)

W* = NS/(NS/W)* (g)Wadd = W* - W (g)

EXAMPLE (continued) :

Selected Calculated

range : water :

(NS/W)* W* (g) Wadd (g)

1 1,90 16,78 0,00

2 1,6 19,91 3,13

3 1,2 26,54 9,76

4 1 31,85 15,07

5 0,7 45,50 28,72

6 0,4 79,63 62,85

7 0,2 159,25 142,47

8 0

Add the listed amount (Wadd) of pure water to each sample. Sample preparation is now complete.

12 APPENDECES 91

91

12.2.2 Saturation testA) Use increasing amounts of icing sugar and during continuous mixing add them to the samples. The weight of sugar to add should be a little more than enough to saturate the sample. Having added the sugar, close the sample containers carefully and put them in a common temperature controlled bath, where they should be kept at constant temperature and well mixed for several hours.Select the temperature of the bath to equal for example 60 C. The actual value is not critical, it can be in the 40-70 C range, but it should be kept constant by a temperature controller at its set-point.

B) Saturation of the samples with sugar needs good mixing and even so may take several hours. It can be regarded as complete when the change in the concentration of the sample liquid becomes negligible.

12.2.3 EvaluationA) When the saturation test is complete, remove undissolved crystal sugar from the samples and determine concentration, sugar content and purity data for each sample in the laboratory.Calculate the S/W (sugar to water) ratio for each sample and by using the pure sugar solubility data valid for the selected sample temperature calculate the solubility coefficient for the samples.

SOL. QS/W = ------------- (g sugar/100 g water) (100 -Q)

Use look-up tables (collected by Grut, or Vavrinecz) to get data valid for pure sugar solubility at the selected saturation temperature. For completeness some of these data are presented here:

Sugar solubility data (g/100 g water) for pure solutions according to Grut and Vavrinecz:

Temperature (C) Grut (SG) Vavrinecz (SV)50 262.0 258.6355 277.0 272.8160 293.0 288.5665 311.0 305.9670 331.0 325.15

S/W S/W SAT. COEFF. = --------- , OR SAT. COEFF. = ----------

SV SG

EXAMPLE (continued) :

(In this example SV is being used).

MEASURED AND CALCULATED DATA AT SATURATION :

SOL (%) S (%) Q (%) S/W SAT.COEFF.

1 83,71 54,00 64,51 331,49 1,149

2 82,50 54,70 66,30 312,57 1,083

3 80,50 57,46 71,38 294,67 1,021

4 79,30 59,20 74,65 285,99 0,991

5 77,90 62,20 79,85 281,45 0,975

6 76,20 66,30 87,01 278,57 0,965

7 75,10 70,10 93,34 281,53 0,976

8 1,000

B) Calculate the final nonsugar to water ratios (NS/W)** of the samples based on the laboratory data, then draw the Saturation Coefficient versus (NS/W)** chart using Excel.

EXAMPLE (continued):

(NS/W)** SAT.COEFF.

12 APPENDECES 92

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1 1,824 1,149

2 1,589 1,083

3 1,182 1,021

4 0,971 0,991

5 0,710 0,975

6 0,416 0,965

7 0,201 0,976

8 0 1,000

SAT.COEFF.

0,96

0,98

1

1,02

1,04

1,06

1,08

1,1

1,12

1,14

1,16

0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2

SAMPLE NONSUGAR TO WATER RATIOS (NS/W)**

Fig. A.2

It can be seen (Fig. A2.) that the linear part of the chart starts at about (NS/W)** = 1.2. This belongs to sample numbers 1, 2 and 3. Separate these data on another chart and do the linear least square calculation in Excel (Fig. A3.) :

SATURATION COEFFICIENT

y = 0,1936x + 0,788R2 = 0,9717

1

1,02

1,04

1,06

1,08

1,1

1,12

1,14

1,16

1 1,1 1,2 1,3 1,4 1,5 1,6 1,7 1,8 1,9


Fig. A.3

Now we already have the “m” and “b” parameters :

m = 0.194 b = 0.788

12 APPENDECES 93

93

Let us continue with the part of the chart valid for lower nonsugar to water ratios (sample numbers 4, 5, 6, 7).Calculate

SAT.COEFF - m.(NS/W)** - b data for these samples and do again a least squares fit in Excel for these data using 1-b as Y axis intercept :

(NS/W)** SAT.COEFF. S.C.-m.(N/W)**-b

1 1,824 1,150

2 1,589 1,085

3 1,182 1,022

4 0,971 0,992 0,0150

5 0,710 0,977 0,0498

6 0,416 0,967 0,0969

7 0,201 0,977 0,1489

8 0,000 1,000 0,2110

Fig. A.4

Now we have completed the task by finding from the data fit :

c = - 2,47

The complete set of parameters is :

m = 0,194b = 0,789c = - 2,47

Fig. A5. shows the sample data on the saturation coefficient and the value of the saturation function using the above set of quality parameters.

SATURATION COEFFICIENT - m.(NS/W)** - b

y = 0,211e-2,4677x

R2 = 0,9423

0,0000

0,0500

0,1000

0,1500

0,2000

0,2500

0,000 0,100 0,200 0,300 0,400 0,500 0,600 0,700 0,800 0,900 1,000


12 APPENDECES 94

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SAMPLE SATURATION COEFFICIENTS AND VALUES OF THE SATURATION FUNCTION

0,9

0,95

1

1,05

1,1

1,15

0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2

NONSUGAR TO WATER RATIO

SAT.COEFF.

SATFUN.

Fig. A.5

NOTES:1. The Wiklund-Vavrinecz saturation function is the result of extensive research on sugar solubility in beat sugar molasses. Unfortunately, there are very few similar data on cane sugar molasses. However, there seems to be no reason why the basic equation could not be used with cane sugar molasses. Some of the scarce data available indicates that the “m”, “b” and “c” parameters can differ significantly from those valid for beat sugar. The result of these differences is more pronounced with low purity syrups. Based on data collected by Thieme on cane syrups the parameters have been determined (L.Rózsa: Sucrose solubility in impure cane sugar solutions, INTERNATIONAL SUGAR JOURNAL, 2000, VOL. 102, 230-235):

m = - 0, 06265 b = 0,982 c = - 2,1

2. It is important to do the saturation test starting with low purity (C product) sample (“original sample”), in order to get fairly accurate linear equation on the linear part of the function. Accuracy can be improved by using more samples, too.3. The first (exponential) part of the saturation function can quite often be well represented by a constant “c” usually equal to -2.1, or -1.8.4. How often should the syrup quality parameters be determined depends on several factors, like type of the sugar beat or cane processed, fertilizer being used by the farmers, storage temperature etc. and has to be determined based on local experience.

APPENDIX 2 : CONFIGURATION DATA SHEETS

12 APPENDECES 95

95

12 APPENDECES 96

96

12 APPENDECES 97

97

12 APPENDECES 98

98

12 APPENDECES 99

99

SUBJECT INDEX… 100

100

SUBJECT INDEX

a

analoginput 24…26, 43, 59, 72output 25…27, 32, 39, 64, 73current ranges 23

active instrument 31, 37, 51, 56APPENDIX 89alarm 20, 23, 31, 34, 35, 74

history 35limit data 59

average supersaturation 48, 50, 70, 74

b

basic key operations 35, 55boiling point rise 11

c

capacitance 11change feed syrup purity

19, 32, 38…40, 60, 63circulation 9, 11communication (digital) 14, 16…20, 22, 23,

25, 31…33, 36, 38…43, 47,49, 51…54,57, 63, 71, 72, 75, 76COMX ports 18, 38, 57Ethernet 17, 18, 22, 23, 25, 32, 38, 39,52…54, 57, 71, 76

configure 31, 37active instrument 37, 51communication (COMX) 52communication (Ethernet) 53password 31, 33, 35, 52seeding 33, 50strike active signal 42third input 43

conductivity 5, 11conglomerates 9, 10construction details 28consistency 5, 11, 17, 19, 22, 34, 45cost of production 5, 6, 10crystallization 5, 6crystallization parameter 48, 50crystal

content 5, 9, 11, 12, 14, 15, 17…1922

content bias 48fines 10footing 8, 9, 20, 32, 44, 47…51growth simulation 48, 49mean size 14, 17…19, 22, 43,

44, 47, 49, 68size distribution 10

d

datainputs 17, 34, 37, 55, 57, 59 71outputs 19, 59calculated 14, 16, 22, 32…35, 37, 48, 64,

76transmission 76, 82

date and time 56default settings 34density 5, 11…13, 15…20, 22, 32…34, 43, 44,

49, 51, 58, 63, 64, 67, 71digital

inputs 14, 16, 18outputs 16, 20, 25, 32, 50, 51, 62, 63communication: see: communicationDIN1 input 18, 19, 21, 42, 62,DIN2 input 19, 20, 22, 33, 51, 52, 63DIN3 input 19, 22, 60, 62DO1 output 20, 23, 32, 50, 51,63DO2 output 19, 20, 23, 32, 50, 51, 53

display 31, 55, 66, 67main display: see main displaystandard display 57, 70strike history 31, 33, 70system information 31, 71test data 31, 72trend 68

e

enclosure 13, 15, 24, 25, 29engineering units 59Ethernet communication: see: communication

Ethernetcable specification 76connection settings 77TCP / IP implementation 78testing 77troubleshooting 78

events 74

f

feed syrupchange 19, 32, 38…40, 60, 63purity 15, 22, 32, 35, 41, 43, 47, 48, 50, 57, 60quality parameters 6, 15, 61, 89

front panel 23further reading 13

g

h

i

instruments 11, 12, 14I1, I2 37, 51, 54…56, 65…67, 71Tag 37,55, 56, 65…67, 71


101

in-line measurementI / O wirings 25

k

K-PATENTS refractometer 5, 12, 14, 15, 17, 18, 22…24, 32, 57, 57, 71, 81application examples 39

l

laboratory data 14, 15, 18, 22, 52, 57, 58feed syrup purity: see change feed syrup

puritycrystal content 17…19, 22, 44, 68mean crystal size 14, 17…19, 22, 44, 68

level 18, 19, 22, 34, 43…45, 47, 49, 58, 60, 67, 68, 70

m

man-machine interface 19main display 18,31, 32, 34…37, 41, 43, 49, 55,

56, 65…69massecuite

capacitance 11consistency 5, 11, 17, 19, 22, 34, 35conductivity 5, 11density: see densityelectrical parameters 11level: see levelparameters 9, 11, 14, 15, 19, 22,

23, 34, 69, 70solids content (brix) 15,19, 20, 22, 43…45,

58, 67, 71temperature 6, 7, 9, 11, 12, 15, 17…19,

22, 34, 35, 43…49, 57, 58, 67, 71, 73, 74

viscosity 11, 45, 67microwave probeMODBUS

commands 78, 83data types 84protocol 81register set 85

mother liquor,concentration 5…7, 11, 12, 15, 17…19,

22, 34, 35, 43…49, 57, 58, 67, 71, 74purity 6, 11, 14, 15, 17, 19, 22, 34, 43, 60,

67motor

double-speed 48calibration parameter 48consumption 11, 15…19, 22, 32, 42, 45,

46, 58, 63cut-off consumption 42ON / OFF 19, 42, 63single-speed 47

mounting the refractometer 13

n

nucleation 7…10, 17spontaneous 9, 10, 70

o

on-line measurement 6, 10…18, 22, 33, 34, 37, 41, 43, 49, 54, 57, 60

optional data input 18, 43

p

password 50…52, 65configuration 31, 33, 35

PHASE1, PHASE2 45, 46process

inputs 22, 25refractometer 5, 12, 14, 15,39, 53, 57

Process Control System (PCS) 6, 14, 17, 19, 32, 39, 42, 43, 76

command 19, 20, 33, 37, 50, 51, 63, 72product quality 5, 6, 9, 10, 70

q

quality parameters (syrup) 6,15, 22, 35, 61, 89

r

range data 58, 59range excursion 34, 59, 60, 74rate of production 10recirculation (crystals) 9, 10refractive index 11, 12

s

saturationfunction 62, 89test 90, 91, 94

seeding 6, 32, 44, 47, 49…51, 63automatic 5, 14, 16, 17, 19, 20, 22, 51, 65full seeding 8, 9manual 31, 33, 51, 65methods 6, 32modes 49on DIN2 33on command from PCS 33, 51point 5, 6shock seeding 7set-point 7,slurry 7parameters 35valve 16, 20, 23, 32…35, 50, 51, 60, 63,

65warning 20, 23, 32, 35, 50, 51, 63, 67, 71

seededinput 18, 59


102

output 19, 20, 23, 32, 50, 51, 63SeedMaster optional software 5SeedMaster 2 14

active mode 15, 18, 34, 42, 74basic key operations 35, 55calculated data 16, 22, 32…35, 48, 64, 76,

84communication: see communicationconfiguration 31, 35, 37, 41construction details 28dimensions 24display 14electrical connections 22, 24, 25, 34features 22, 31, 32keyboard 14, 23, 25, 28, 36, 38main board 29mounting 22modes of operation 14operator’s station features 31principle of operation 16register set (Ethernet) 85selection tree 21, 36set up 31, 55seeding features 32seed warning: see seedingseeding valve output: see seedingsensor calibration (third input) 43…45specifications 22standard display 70stand-by mode 15, 18, 35, 42, 67temperature range 23transmitter features 30

sensor (refractometer) locations 13(density, brix) calibration 43…45

set up 55analog inputs 57analog output 64digital I / O 62display 55seeded input 59SeedMaster 2 55strike active input 18, 19, 22, 31, 42syrup parameters 61

slurry 8, 9, 20, 32, 47, 63soft keys 36solubility coefficient 85standard current

inputs 47outputs 20

strikeactive input 18, 19, 22, 31, 42time 67status 67history 20, 22, 31, 33, 48, 69

supersaturation 6, 9, 33average 48, 50, 70, 74calculation 6critical values 7trajectories 8

syrupconcentration 10, 14purity 11quality parameters 5, 84

system information 69

t

tag 37, 55, 56, 65temperature

data 18, 44, 46, 48, 74bias 58

terminal connections 22, 24…28test data 20, 31, 72

analog inputs 72analog outputs 73digital I / O 73communication (COMX) ports 73other data 74events 74MODBUS registers 75

third input 18, 43…45, 49time scale 56transmitter parameters 59

u

v

viscosity 11, 45, 67

w

wait for start 35, 67Wiklund-Vavrinecz 89

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