6-23-0

7/28/2019 6-23-0

1/13

evisiondication

uopUOP LLC 25 East Algonquin Road Des Plaines, Illinois 60017-5017 USA

STANDARD SPECIFICATION

6-23-0 Page 1 of 13

BASIC PROCESS CONTROL SYSTEMS

Form QUA-03-2

DATE STATUS APVD AUTHD

12FEB02 NEW RED KAR

1. GENERAL

1.1 Scope

a. This Standard Specification describes the functionality and requirements (including dynamicperformance) of the Basic Process Control System (BPCS) for non-safety related controlsystems. This Standard Specification does not cover specific hardware and software details.This is left to the detailed engineering Contractor and/or Owner. Specific operational andmaintenance requirements of this equipment are the responsibility of the Owner and/orContractor.

b. Exceptions or variations shown in the UOP Project Specifications take precedence overrequirements shown herein.

1.2 References

Unless noted below, use the edition and addenda of each referenced document current on the dateof this Standard Specification. When a referenced document incorporates another document, usethe edition of that document required by the referenced document.

a. Normenarbeitsgemeinschaft fr Me- und Regeltechnik {in der chemischen Industrie},(NAMUR), NE 43 engl., Standardization of the signal level for the breakdown information ofdigital transmitters.

b. National, state, and local laws and codes

7/28/2019 6-23-0

2/13

evisiondication



6-23-0 Page 2 of 13


Form QUA-03-2


12FEB02 NEW RED KAR

2. CONTROL SYSTEM PERFORMANCE

2.1 General

a. The control response period shall be used as the measure of BPCS performance. The controlsystem can perform proportional, integral, derivative (PID) control using any combination ofhardware and software described in sections 2.2 through 2.5. Functions (e.g. signal selectors,summers, calculation blocks, etc.) associated with controllers shall not increase the controlresponse period.

b. The maximumallowable control response period is shown in Table 1:

Table 1

Process Category

Maximum Control

Response Period *

X, (Milliseconds)

Flow

Pressure 300 ms

Differential Pressure

Temperature 1000 ms

Level 1000 ms

Designated Fast Process Control Loops 150 ms

All Others (Analysis, Density, pH, Etc) 1000 ms

* Shorter control response periods may be required for certain control services (e.g.compressor antisurge, reactor temperature, etc.). Multivariable advanced processcontrol may be implemented with longer control response periods.

c. In general, the shorter the control response period, the better the control performance. Controlresponse periods longer than those listed above may degrade performance and affect unitoperability.

d. Sections 2.2 through 2.5 show examples of typical techniques used for flow control loops.Other process categories, not shown, shall follow the same techniques. See Table 1 for thevalue of the maximum control response period (X) in each figure.

7/28/2019 6-23-0

3/13

evisiondication



6-23-0 Page 3 of 13


Form QUA-03-2


12FEB02 NEW RED KAR

2.2 Control Performance for a Distributed Control System (DCS) using 4-20 mA Field Wiring

a. Applies to process control systems whose field wiring is as shown in Figure 1.

Figure 1

b. The control response period shall be the total time to perform the following steps (See Figure 2):

(1) Analog to Digital conversion of 4 - 20 mA signal and writing value to input/output (I/O)processor

(2) Pass the input value to the PID controller to perform the PID algorithm(3) Execute the PID algorithm(4) Pass the calculated PID output value to the I/O processor(5) Digital to analog conversion to generate the 4 - 20 mA output signal

Figure 2

DCS

4-20mA4-20mA

Xms0ms

Distributed Control System

Maximum Control Response Period

Time

(milliseconds)

A/D

conversion of4-20 mA

signal and

write value to

I/O processor

4-20 mA

InputSignal

Bus

transmissiontime to pass

the input

value

PID Algorithmexecution in

Controller

Bus

transmissiontime to pass

the output

value

D/A

conversion togenerate

4-20 mA

output signal

4-20 mA

OutputSignal

1 2 3 4 5

7/28/2019 6-23-0

4/13

evisiondication



6-23-0 Page 4 of 13


Form QUA-03-2


12FEB02 NEW RED KAR

2.3 Control Performance for Single Loop Controller using 4-20 mA Field Wiring

a. Applies to process control systems whose field wiring is as shown in Figure 3.

Figure 3


(1) Read the 4 - 20 mA signal by the single loop controller(2) Execute the PID algorithm in the single loop controller(3) Generate and output the 4 - 20 mA signal by the single loop controller

Figure 4

Single Loop

Controller

4-20mA

PV

Output

100%0%

SP

SP

PV

4-20mA

Xms0ms

Single Loop Controller


Time

(milliseconds)

Read

4-20 mA

Signal

4-20 mA

Input

SignalPID Algorithm

execution in

Controller

Generate

4-20 mA

output signal

4-20 mA

Output

Signal

1 2 3

7/28/2019 6-23-0

5/13

evisiondication



6-23-0 Page 5 of 13


Form QUA-03-2


12FEB02 NEW RED KAR

2.4 Control Performance for a Fieldbus System Performing PID Control within the DCS

a. Applies to process control systems using fieldbus as shown in Figure 5.

Figure 5


(1) Execute the Analog Input Function Block in the transmitter and publish the process variablevalue on the fieldbus

(2) Receive the process variable at the DCS and retransmit it internally to the controller(3) Execute the PID algorithm

(4) The total bus transmission time to publish the calculated PID output value on the fieldbus(5) Execute the Analog Output Function Block

Figure 6

DCS

Fieldbus

Xms0ms

Distributed Control System


Time

(milliseconds)

Analog

Input

Function

Block in

FieldDevice

Fieldbus

Communica

tions

DCS Bus

Transmission

Time to

Controller

PID

Algorithm

Execution

in

Controller

Fieldbus

Communica

tions

DCS Bus

Transmission

Time to I/O

Modules

Analog

Output

Function

Block in

FieldDevice

Fieldbus

Field

Device Fieldbus

Field

Device

1 2 3 4 5

7/28/2019 6-23-0

6/13

evisiondication



6-23-0 Page 6 of 13


Form QUA-03-2


12FEB02 NEW RED KAR

2.5 Control Performance for a Fieldbus System Performing PID Control within the Field Devices

a. Applies to process control systems using fieldbus as shown in Figure 7. Note the PID controllermay be located within the final control element hardware or field transmitter.

Figure 7

b. PID Controller within the Final Control ElementThe control response period shall be the total time to perform the following steps (See Figure 8):

(1) Execute the Analog Input Function Block in the transmitter and publish the process variablevalue on the fieldbus

(2) Receive the process variable at the controller and execute the PID algorithm(3) Execute the Analog Output Function Block

Figure 8

DCS

Fieldbus

AI PIDAO AI

PID AO

Xms0ms


Time

(milliseconds)

Analog

Input

Function

Block in

FieldDevice

Fieldbus

Communications

PID

Algorithm

Execution

in

Controller

Analog

Output

Function

Block in

FieldDevice

Fieldbus

Field

Device Fieldbus

Field

Device

1 2 3

7/28/2019 6-23-0

7/13

evisiondication



6-23-0 Page 7 of 13


Form QUA-03-2


12FEB02 NEW RED KAR

c. PID Controller within the Field Transmitter

The control response period shall be the total time to perform the following steps (See Figure 9):

(1) Execute the Analog Input Function Block in the transmitter(2) Execute the PID controller Function Block in the transmitter and publish the PID controller

output value on the fieldbus(3) Receive the PID controller output value and execute the Analog Output Function Block

Figure 92.6 PID Equation Form

The PID controller equation should be of the form in which the derivative action is only based onthe change in process variable. Those forms of the PID equation in which the derivative action is

based on the change in error (and derivative is used) cause the controller output to spike when theoperator changes the setpoint.

2.7 Controller Setpoint Tracking

Controller setpoints should track their respective process variables while in manual mode. Forcascade loops, the output of each primary controller should track the setpoint of its respective

secondary controller when the secondary controller is not in cascade mode. All primarycontrollers should also revert to manual mode when their associated secondary controllers are notin cascade mode. This allows the controller output tracking to take effect, thereby facilitating

bumpless transfer when cascade is re-established. Proper configuration of tracking allowsoperators to change the mode of any controller from manual to automatic or from local automaticto cascade without causing a process disturbance.

2.8 Controller Central Processing Unit Capacity

The control system Central Processing Unit(s) (CPU) shall include sufficient capacity to permit50% of the slowest controllers at 1000 ms to be changed to 300 ms. Changes to theexecution/acquisition rate may be required during process unit operation. Total system sparecapacity, including the above, shall be the responsibility of the Owner.

Xms0ms


Time

(milliseconds)

AnalogInput

Function

Block in

Field

Device

Fieldbus

Communications

PID

Algorithm

Execution

in

Controller

AnalogOutput

Function

Block in

Field

Device

Fieldbus

Field

Device Fieldbus

Field

Device

1 2 3

7/28/2019 6-23-0

8/13

evisiondication



6-23-0 Page 8 of 13


Form QUA-03-2


12FEB02 NEW RED KAR

3. OPERATOR WORKSTATION

3.1 General

The operators workstation shall include as a minimum, a display monitor and keyboard. Systemsmay be equipped with multiple display monitors and one keyboard per operating position. TheOwner's operating and staffing philosophy shall determine if two or more process units can becombined into one operators workstation. In general, no more than 100 control loops shall beoperated from a single operator workstation. Systems with more than 100 control loops peroperator shall be analyzed carefully to ensure that the operator workload is manageable.

3.2 Details

a. The workstation software shall include scan tasks for interfacing between the real-time tagdatabase and the detailed controller functions. The software shall also provide graphic displays,trend and report capabilities, event, and alarm management tools.

b. The real-time tag database shall be capable of updating all tags in a period no greater than 1second.

c. Each workstation shall be powered from the Uninterruptible Power Supply via a separate circuitbreaker. Each workstation shall be capable of being taken off-line or powered downindependently, without affecting the operation of the control system, including the otherworkstations.

d. Display requirements shall include overview, group, point (individual loop), trend (single and

multi-loop), alarm, process graphics, and equipment status and diagnostics.

e. Each workstation shall have the capability of printing the information displayed on the screen.Each workstation shall have access to a minimum of two printers, of which at least one should

be a color printer.

f. The operator interface software shall be capable of acting as a Dynamic Data Exchange (DDE)or OLE (Object Linking and Embedding) for Process Control (OPC) client or server to sharereal-time data with DDE or OPC compliant applications.

3.3 Graphic Displays

a. All control parameters shall be accessible through the graphic display. Navigation through thedisplays should be easy and intuitive. One overview graphic display per process unit shall be

provided in order to quickly access the detailed graphics. Viewing of information in real-timeshall include all remote setpoints whether calculated or not.

b. All loop controllers shall have faceplates. These faceplates shall allow easy access to tuningvariables, trending, setpoint values (both local and remote), alarm settings, auto/manual,remote/local, and percent output.

c. Pop-up functions (faceplates, trends, reports etc.) should allow large amounts of detailedinformation to be quickly accessed without extensive clutter on a process graphic.

7/28/2019 6-23-0

9/13

evisiondication



6-23-0 Page 9 of 13


Form QUA-03-2


12FEB02 NEW RED KAR

d. The DCS output display for all control valves shall be configured such that it is readily apparent

to the operator how the output must be changed to manually open or close the valve.Configuration such that an indication of 0% output is closed and 100% is open regardless ofvalve failure action, or other labeling methods, may be used depending on the Owner's operating

philosophy.

3.4 Password Protection

Configuration and on-line operation should be password-protected with at least three levels ofsecurity (Engineering/configuration, supervisor, and operator) to avoid inadvertent changes.

4. DATA STORAGE AND RETRIEVAL

4.1 Historical Data Storage and Trend Display

a. When a data storage and retrieval function is specified for a process variable, the value shall bestored digitally in non-volatile memory or hard drive within the control system equipment, or inauxiliary systems communicating with the control system. The stored information is used forthe following purposes:

(1) Determination of plant material balances(2) Trend analysis of equipment performance(3) Troubleshooting and analysis of malfunctions(4) Monitoring the day to day operation

b. For the purpose of trouble shooting and analysis of malfunctions, the ability to retrieve and

display the actual instantaneous sampled process data, rather than the averaged ormaximum/minimum values, is essential.

c. The process variable shall be sampled and the instantaneous value shall be stored at intervals often seconds or less. Storage capacity shall be sufficient to store process variable data for at leastthe immediately previous 7 day period. The control system equipment shall be able to accessand display the stored data at the operator station console and/or other console on demand at anytime. The control system equipment shall be capable of selecting for display the instantaneousvalues stored in any 1 hour period within the 7 days of data. Stored data shall not be erased bydisplay. Update of data shall be on a point-by-point basis to ensure that the immediately

previous 7 days of data are available at any time.

d. Storage capacity that is capable of retaining daily averages and weekly averages for a period ofone year shall also be provided. The control system equipment shall be able to access anddisplay the stored data at the operator station console and/or other console on demand at anytime.

e. Data stored for historical review shall be accessible in grouped trend display format. Thegrouping of the process variables shall be logical with respect to the process. Configuration oftrend displays shall have the capability for operators to set up additional trend displays ofselected variables for specific troubleshooting activities. Different colors shall be used for eachvariable trended. Additional trend display capacity shall be available for at least 10 percent ofthe historical trend display groups.

7/28/2019 6-23-0

10/13

evisiondication



6-23-0 Page 10 of 13


Form QUA-03-2


12FEB02 NEW RED KAR

f. Data for process variables where a data storage and retrieval function is not specified shall also

be stored digitally in a non-volatile memory or hard drive system if desired by the Owner of theprocess unit. For these variables averaged data or various data compression techniques areacceptable. The sampling interval, storage period, and display capabilities shall be selected bythe Owner of the process unit.

g. The manufacturers capabilities with respect to the subject of data storage and retrieval shall bethoroughly reviewed by the Owner/operator of the process unit before deciding to accept a

particular system.

h. The control system must be capable of archiving historical data onto removable media.

4.2 Controller Tuning Display

a. Each loop controller shall have a trending display for tuning. This tuning display shall show theloop controller tuning values and include the capability to change the loop controller tuningvalues while trending. Different colors shall be used for each parameter trended. The minimumcontroller parameters trended shall be:

(1) Setpoint(2) Process variable(3) Controller output signal

b. Trending intervals shall be user selectable between 0.25 seconds to 5 seconds. The overall trenddisplay must show as a minimum between 1 minute and 20 minutes of trending per Table 2:

Table 2

Sample Interval Minimum Duration of Screen Trend

0.25 seconds (4 times per second) 1 minute

0.5 seconds (2 times per second) 2 minutes

1 second (1 time per second) 4 minutes

2 seconds (0.5 times per second) 8 minutes

5 seconds (0.2 times per second) 20 minutes

5. ALARMS

5.1 General

a. Alarm functions shall be implemented using the data acquisition and shared processingequipment of the control system. All alarms shall be visually and audibly indicated and shall beconnected to event logging facilities.

7/28/2019 6-23-0

11/13

evisiondication



6-23-0 Page 11 of 13


Form QUA-03-2


12FEB02 NEW RED KAR

b. The UOP Project Specifications include the minimum process based alarm requirements and

initial settings. During detail design, and following the Owners Process Hazard Analysis,additional alarms may be required. The Contractor shall be responsible for adding these alarmsand determining their proper settings. UOP will participate in pre-commissioning activities andreview changes from the UOP Project Specifications. If an alarm setting from the UOP ProjectSpecification appears to be inappropriate, or a nuisance alarm is anticipated, UOP personnel onsite will identify these alarms and advise the Owner.

5.2 Critical Alarms

a. These alarms are considered to be of high importance and are associated with a processcondition or a special circumstance that requires immediate operator action. Examples areshutdown pre-alarms, shutdown alarms, and critical equipment alarms.

b. Alarms in this category require a unique display and audible tone to clearly distinguish themfrom non-critical alarms. Critical alarms shall be distinguished from other alarms by a uniquecolor, grouping, or graphical display on the DCS and/or displayed on a separate, backlighted-nameplate annunciator panel located above or adjacent to the operator station.

c. Hardware-based critical alarm functions are an acceptable alternate and shall be repeated intothe operator station alarm display and logging facilities.

5.3 Non-Critical Alarms

This category alarm is generally for services not associated with a shutdown function or criticalequipment protection.

6. HART (HIGHWAY ADDRESSABLE REMOTE TRANSDUCER) COMMUNICATIONS

Analog 4 20 mA input and analog 4 20 mA output cards shall not prevent HART communications forconfiguring smart field devices using HART handheld communicators or PCs using HART modems. Ifanalog 4 20 mA input and output cards cannot allow for HART communications then HART filters shall

be installed in the DCS cabinets to allow for HART communications.

7. TRANSMITTER FAILURE DETECTION

Analog 4 - 20 mA input cards shall be capable of differentiating between an out of range measurementsignal and a failed transmitter signal.

The control system vendor shall coordinate with the Contractor to determine what field device failurealarm levels have been selected (such as NAMUR NE 43 engl. compliant transmitters).

Upon detection of either high or low transmitter failure alarm signal, the control system shall generate acritical alarm (visual and audible).

8. HARDWIRED MANUAL CONTROL CENTER SWITCHES

When specified, hardwired manual control center switches shall be installed in appropriately locatedsubpanels attached to the BPCS operator console. Duplication of the manual switch functions within theBPCS is optional; any such duplication shall consider the effects of failure modes of the BPCS.

7/28/2019 6-23-0

12/13

evisiondication



6-23-0 Page 12 of 13


Form QUA-03-2


12FEB02 NEW RED KAR

9. INPUT AND OUTPUT (I/O)

9.1 Thermocouple Input

The thermocouple input shall be capable of measuring and linearizing the following types ofthermocouples:

Type: E, J, K, T (grounded or ungrounded).Digital Accuracy: 1.5F, (0.83C)Resolution: Minimum 12 bits

Cold junction compensation shall be provided.

9.2 Resistance Temperature Detector (RTD) Input

The RTD input must be capable of measuring and linearizing the following type of 3 and 4 wireRTDs:

Type: PT100Digital Accuracy: 0.5F, (0.28C)Resolution: Minimum 12 bits

9.3 Analog 4-20 mA Input

Non-isolated or isolated 4 - 20 mA input may be used depending on Owner preference and localcodes or practices.

Normal measuring range: 4 - 20 mAResolution: Minimum 12 bits

9.4 Analog 4-20 mA Output

Non-isolated or isolated 4 - 20 mA output may be used depending on Owner preference and localcodes or practices.

Output range: 4 - 20 mAResolution: Minimum 12 bits

9.5 Fieldbus I/O

Fieldbus technology, such as, Foundation Fieldbus H1 segments and Profibus PA Fieldbus maybe used for linking, operating, and controlling field devices as long as the control response periodmeets the requirements of this Standard Specification.

7/28/2019 6-23-0

13/13

evisiondication



6-23-0 Page 13 of 13

BASIC PROCESS CONTROL SYSTEMSDATE STATUS APVD AUTHD

12FEB02 NEW RED KAR

9.6 Digital Inputs

Digital inputs shall be true when contacts are closed (energized) and false when contacts are open(de-energized). Inputs may be either sinking (where current flows from the I/O module throughthe external device to the return) or sourcing (where current flows to the I/O module from theexternal device).

9.7 Digital Output

a. Contractor to determine maximum current load. Each output channel shall power no more thanone final control element. Details shall be coordinated between the Contractor and the controlsystem supplier.

b. Outputs to solenoid coils or other inductive loads shall include a high voltage suppressor ordiode to provide protection against high induced voltage. The protection devices shall be

provided by the Contractor or with the solenoid coil.

10. PROCESS CONTROL SOFTWARE CONFIGURATION

The control system shall be capable of being modified and performing back-ups of any portion of thesystem (e.g. process control software, graphical user interface package, historian, asset managementapplications, etc.) while the process unit(s) are operating, without interrupting the control software,upsetting the units, or preventing the operator from controlling the unit(s). Graphical methods ofconfiguration are preferred.

11. CONTROL SYSTEM UNINTERRUPTIBLE POWER SUPPLY

The Uninterruptible Power Supply (UPS) for the control system shall maintain power to all control centerequipment, field transmitters, controller output field devices, and shutdown circuits for a minimumduration of one hour upon loss of source power.

12. LOOP POWER SUPPLY

The power supplies for field devices shall have separate AC power supply breakers or fuses so a singlepower supply can be taken out of service for replacement or repair. The power supplies shall receive theirAC power supply from the Control System UPS.

13. SINGLE LOOP INTEGRITY

Single loop integrity to prevent a single component failure from affecting more than one control loop,although recommended, depends on Owner requirements for the site. The Owner shall determine the needfor redundancy of devices such as I/O processors, CPUs, power supplies, operator workstations,communications, etc.

Documents

6-23-0