tManager Performance Considerations

7/30/2019 tManager Performance Considerations

1/19

anager er ormance ons era ons

2013 Online Development Inc. All Rights Reserved. 1 J une 27, 2013


2/19

Topics

Performance overview

Rockwell Automation reference manuals

RA Logix Design recommendations

RA EtherNet/IP recommendations

OLDI tManager performance optimization recommendations

tManager EtherNet/IP Communication options

Database communication



3/19

Typical Performance Landscape

There are many factors that affect overall throughput of yourtManager system ..

ControllerNetwork or

ControlLogixBackplane

tManagerBusinessEthernet Database

Controller ModelControlLogix L63

vs L75, etc.

Rockwell DesignTi s

Backplane vsFront Ethernetport

Type of EthernetBridge

Trigger ScanTimes

OLDI Best

PracticesTri ers/End oints

NetworkConfigurationTransaction rates

FirewallsNetwork Loadin

DatabaseMaintenance &Design

Table Design --contains

Time Slice Continuous,

Periodic & Event-based tasks

DINTS

ENBT vs EN2TvsEN3T

EtherNet/IPDesignGuidelines

/MapsUse of Transaction

LogsUse of Store &

Forward

#of hopsetc

n ex eys on eappropriatecolumns

Stored Proceduredesign -- considerimpact of locks on

Single DimensionArrays

System Log

configurationHandshaking

eav y usetables, views, etc.



4/19

Rockwell Automation Design Documents

Referenced While Preparing this PPT

ControlLogix and CompactLogix Design Documents. . .

ExpandPerformance and Capacity Guidelines Chapter 2 of theLogix5000 Controllers Design Considerations manual has information concerning task

scheduling and time slice setup for optimum performance. Pub. 1756-RM094F-EN-P

Chapter 3 of theLogix5000 Controllers Design Considerations manual contains guidelines for usingvarious Logix data types

http://www.rockwellautomation.com/solutions/integratedarchitecture/resources4.html#top50

EtherNet/IP Performance Guidehttp://literature.rockwellautomation.com/idc/groups/literature/documents/ap/enet-ap001_-en-p.pdf



5/19

Logix Optimization: Logix Time Slice

If you have a continuous task, RSLogix 5000 & Studio 5000 allow you to allocate a SystemOverhead Time Slice (SOTS), which is a percentage of the CPUs time reserved forbackground CPU functions such as:

Communicating with programming & HMI devices Responding to messages Serial port message & instruction processing Alarm instruction processing

e anager uses ass unconnece messagng, processe n e me s ce

The SOTS only affects messaging performance if a continuous task exists

The default value is 20%

Raising the SOTS increases the scan time of the continuous task, but should increase thenumber of messages per second that are sent between the tManager and Logix processor

The recommended SOTS setting for a data concentrator is 50% or greater. Suggest starting with


50%. If everything is working well, you can see if raising it higher improves performance further


6/19

Logix Optimization : Task Configuration

When Motion, Periodic, and Event Based tasks are used, configure them

Eliminate task overlaps Allow enough time for the communications task - SOTS

Each task will task switch with the others, executing in 1 msecintervals until all

are complete

For more information on how Logix processors handle different types of tasks,and to see graphical examples of the effects of changing the SOTS and othertask arameters, reference Cha ter 2 in the RALo ix 5000 Controllers Desi n

Considerations manual

The information on this slide is from the Rockwell Automation O timi in Control S stem Per ormance resentation resented at various


,

Automation Fairs. The information is also contained in theLogix5000 Controllers Design Considerationsmanual.


7/19

Logix Optimization : Use DINTS

Use the DINT data type whenever possible. Logix is optimized for 32bit data types, and they are processed faster than other data types

SINT INT DINT REAL

Memory usage for a Tag 4 Bytes 4 Bytes 4 Bytes 4 Bytes

emory eserve or a a n a

UDT

(8 Bit aligned)

(16 Bit aligned)

(32 Bit aligned)

(32 Bit

aligned)

Memory used to access*

236 Bytes 260 Bytes 28 Bytes 44 Bytes

Execution Time for an ADD

instruction * L63 - 3.31 sec L63 - 3.49 sec L63 - 0.26 sec L63 - 1.45 sec

* Assumes all parameters are same data type


The information on this slide is from the Rockwell Automation Optimizing Control System Performancepresentation, presented at various

Automation Fairs. The information is also contained in Chapter 3 of theLogix5000 Controllers Design Considerationsmanual.


8/19

Logix Optimization : Data Structure

Guidelines

Utilize the following data structure guidelines whenever possible Use Single Dimensional Arrays and User Defined Structures when

designing your application

Create tag names that are as descriptive as possible while keeping thems or o mnmze e memory usage an e communca on pac e sze

Use single aliasing to prevent changes to documented logic on upload of

project Create packed UDTs to optimize memory and performance

Use DINT arrays for B3 File usage (avoid bool arrays)

Use the LINT data type (64-bit integer value) to store date and time values





9/19

Logix Optimization : Optimizing UDT

Memory Usage

16 bytes 12 bytes

DATATYPE Sample1BOOL Bit1;SINT Tiny_Value

DATATYPE Sample1BOOL Bit1;BOOL Bit2;SINT Tin Value

INT Small_ValueDINT Big_Value

REAL Float_ValueEND_TYPE

_INT Small_ValueDINT Big_ValueREAL Float_Value

END_TYPE

User defined structures allow you to combine multiple data types (atomic, predefinedor user defined) into a new data type

All elements in a structure are located on a byte (8 bit) boundary

.yields better performance

Group all bits adjacent to each other when creating a user defined structure Reduces the amount of memory used and reduces communications time





10/19

Queuing Applications Reasons Needed

You might need to queue data if you cannot afford to loose data if: there are brief durations of database/network delays

Beore data is written to the tore Forward queue there is a time-out period

that will pass. This method will result in no data loss while waiting fortransaction timeouts

With the method described on the next slide, you cannot sustain data changingfaster than the minimum scan time for long periods of time just short periods



11/19

Queuing Applications -- Implementation

1. Write the controller tags to a temporary queue (array), and thenmove them to the mapped tags when the tManager trigger is

Use the LINT output of a Logix GSV instruction when mapping the time to the database vsusing the tManagers Timestamp macro

your scan rate, and then double it (to compensate for the transaction time-out)

2. Configure a Status Tag for the message path (in the TriggerConfi uration screen of the associated tri er

3. Advance the data from the controller queue to the mapped tagsby monitoring the status tag for values >=20 and 100 = an error has occurred


tags


12/19

RA EtherNet/IP Switch Recommendations

When using Ethernet/IP for control, use an industrial grade switch

Required switch features:

Full-du lex ca abilit on all orts

Recommended switch features: VLAN

Auto-negotiation/manually configurable speed/duplex

The information on this slide is from Chapter 6 of theLogix5000

Controllers Design Considerations manual.

Wire-speed switching fabric

SNMP

IGMP snooping constrains multicast traffic to ports associated with a particular IP multicast group

Port diagnostics

Port-mirroring (required for troubleshooting)

-

STP for loop prevention

QoS

For additional control network uidelines, reference the RALo ix 5000 Controllers


Design Considerations manual and the RAEtherNet/IP Performance Guide


13/19

tManager Optimization: System Log &

Status Tags

When you configure the System log, do not keep theLog detail level setting at-

Only enable the DEBUG mode for System logging if you are instructed to use it by OLDIsupport, and then remember to change the setting back to INFO or one of the other optionswhen you are done

Logging DEBUG messages will have a negative impact on tManager performance

Status Tags

Since the will add loadin on the controller and could affect erformance onl defineStatus Tags for the projects, triggers and endpoints where they are needed and will be usedby the controllers application program



14/19

tManager Optimization: Transaction

Logging & Overrun Timers

Only enable Trigger & Endpoint Transaction Logging as needed for regulatorypurposes, or during troubleshooting & start-up

can process If you have a large transaction, logging the entire

transaction has a reater detrimental effect than ustlogging a specific number of bytes

Trigger and Endpoint Overrun Timers

The overrun features should be enabled sparingly, mainly during troubleshooting, sincethey will slow down the overall throughput of all the triggers on the module. For moreinformation on Overrun Timers, reference the tManager Troubleshooting presentation.

The values entered for the trigger overrun timers need to be greater than the Scan. , ,

module throughput will decrease, and other important events and/or errors may bemissed



15/19

tManager Optimization: Store & Forward

If Store & Forward is enabled on an endpoint, once communications areinterrupted & data is sent to the S&F queuethe number of transactionsprocessed per second may decrease

There is an initial time-out period that depends on either the adapters configuredconnection or the transaction time-out values before writing to the S&F queue is

Writing data to the queue, which is stored on the tManagers compact flash, maytake more time than sending the information to its normal destination

,tManager performance while data from the S&F queue is sent to its intendeddestination



16/19

tManager Optimization: Separate Triggers &

Endpoints

Handshake mode selection effects when the next trigger firing occurs:

When combining transactions under one trigger, remember that the trigger cannotre agan un e compe on o a e messages a er eve o an s a ng.

Therefore, one slow message, or one message with a high level of Handshakingselected, would cause all messages to wait for its completion

For more information on Handshaking, reference the tManager Details and BestPractices presentation

Separate endpoints are recommended if you have a transaction message whichyou might expect to be more time-consuming (x-sec vs.


17/19

tManager Optimization: One

Controller.One Map

Although you can use tags from multiple controllers in a single map, it is notrecommended

If any of a maps input variables are not available when the trigger fires, the trigger ismarked as faulted and will not retry for 60-seconds

If multiple controllers are used in a map, loss of communications with any of theseconro ers w cause e rgger o s op rng un a o e conro ers are onceagain available

If ou need ta s from multi lecontrollers ma ed into a sin le database table atthe same time

Recommend mapping all the tags into a data concentrator controller

Ma ta s from the data collector PLC to the database table in a sin le ma



18/19

tManager EtherNet/IP Communications

EtherNet/IP communication over the ControlLogix backplane is usually fasterthan out one of the front Ethernet ports

Rockwell Automation designed the ControlLogix backplane for speed and ease ofcommunications, so backplane communication to the tManager is always as fast orfaster

er e ou e ron por s compara e o communca on over er e vaa 1756-ENBT

A 1756-EN2T/3T is twice a fast as a 1756-ENBT

Reference Rockwell Automation Knowledgebase document 40784 for acomparison of the different Logix EtherNet/IP Bridge modules

htt ://rockwellautomation.custhel .com/a /answers/detail/a id/4078_



19/19

Database Communication

Configuring several database adapters versus having everything go to/from the

The size of the transactions & speed of the databases response to the ,

and maintenance, do have an impact on throughput
