In this article, I am talking about the Site Acceptance Test (SAT) Procedure of PLC/DCS and How it is done step by step for PLC/DCS.
Site Acceptance Test (SAT) Procedure of PLC/DCS looks like FAT (Factory Acceptance Test) Procedure but some of the steps like firmware check and Scan time check.
The main difference between SAT and FAT is some of the tests that happen in FAT in a factory have been repeated on the Site to check if PLC/DCS is properly functioning on the Site or Not.
But During SAT some special precautions is need to take compared to the FAT test. Because if something goes wrong it is easy to handle on the Factory floor rather than on Site.
Test 1 Overall System Configuration Check.
Test 2 Visual Inspection
Test 3 Power-up Test for Engineering and Operator Workstation
Test 4 Power Up Test
Test 5 I/O Loop Testing
Test 6 Engineering & Operator station Functions
Test 7 Controller CPU Redundancy
Test 8 Power Supply Redundancy
Test 9 Diode O-ring Checking
Test 10 Controller CPU Loading
Test 11 Serial Communication Interface Check
Test 12 Logic Check / Cause & Effect Check
Test 13 System Diagnostic Function
Site Acceptance Test Procedure of PLC/DCS
Test 1: Overall System Configuration Check
Purpose of Test
To verify the system configuration concerning the approved System Configuration drawing.
Test Procedure
Check for the total number of System and Marshalling Cabinets
Check the total number of Engineering and Operator Workstations.
Check for the total number of Serial/Modbus TCP/IP Interface modules.
Check for the total number of other Hardware as per the approved System Configuration and Bill of Material.
Test 2: Visual Inspection
System Cabinet and Marshalling cabinet
Purpose of Test
To perform the Visual / GA check and Internal Arrangement for the System and Marshalling Cabinets.
Test Procedure
Check for a Total number of systems and marshaling cabinets as per the approved GA Drawing.
Overall general assembly, dimensions, and the orientation of the cabinet.
Overall condition, alignment, or any damage.
Check for a Total number of modules as per the approved GA Drawing.
Check for the Quantity/Model of I/O Modules.
Check Quantity and types of Terminal blocks.
Check for TB LED glowing in case of fuse failure.
Functional tests for Utility items (Fans, FFTDU & Lamps)
Check for the Quantity/Model of Relays, Isolators (AI, AO, DI, DO), and Power Feed Modules.
Wiring Check – Ferruling, size & color of wiring, Labels, markers, the proper size of lugs & terminals, cable dressing, etc.
Spot check on loose wires.
Earthing inside the cabinet.
Tabletop Console
Purpose of Test
To perform the Visual / GA check and Internal Arrangement for the Console.
Test Procedure
Check for the Total number of consoles as per the approved GA Drawing.
Overall general assembly, dimensions, and the orientation of the cabinet.
Overall condition, alignment, or any damage.
Check for the Total number of various types of components.
Wiring Check – Ferruling, Labels markers, color & size of wiring, the proper size of lugs & terminals, cable dressing, etc.
Test 3: Power up Test for Engineering and Operator Workstation
Purpose of Test
Power up the system and check for the healthiness of the Engineering and Operator workstations.
Test Procedure
Ensure that Engineering and Operator workstations are connected per system configuration and have all requisite peripherals/accessories.
Boot up the Engineering and Operator workstations as per the approved System Configuration Diagram.
Verify the “Service Connection viewer” icon in EWS & OWS workstations, the bottom right tray is Green to ensure healthiness.
Test 4: Power up Test Controller
Purpose of Test
Power up the system and check for the healthiness of the Controller.
Test Procedure
Verify that all the modules are installed as per the approved GA drawing.
Verify no. of clusters.
Verify that I/O modules are installed as per GA drawings
Verify that controller nodes are connected to the Control network.
Power up the controller and allow the controller to boot.
Power up S800 I/O modules and enable the modules to boot.
Verify that the LED indication on each Primary controller is AMBER.
Verify that the indicator LED on each Secondary controller is not lit.
Test 5: I/O Loop Testing
Purpose of Test
To verify that the I/O Allocation configuration matches with the approved I/O wiring table / IO Allocation document.
Test Procedure
Loop testing will be carried out by feeding the signal directly from marshaling. Loop drawing will be used to identify individual loop wiring details.
For each loop, at least one point of the range should be checked.
Check operator station readings and record each observation.
Loop Type | Loop Description | Loop Details |
---|---|---|
Open Loops | Analog Input Loops | Tag No Description/Range/Units/Alarm Limits as per Point database. Measured variables on 0, 50, 75, and 100 percent of input variation across the Loop Range. Check indication in Graphics also. |
Device Loops (Digital Input) | Tag No. Description as per Instrument IO List. Check the Close & Open, On &Off, Run or Stop status corresponding to Energize & de-energize state of the loops. Check indication in Graphics also. Check for the alarm message in the graphic as well as the alarm list. | |
Device Loop (Digital Output) | Tag No. Description as per Instrument IO List. Check the following: a) 0V & 24V across the loop corresponding to Close/Stop, Open/Start Commands. b) Check for the Continuity across the loop corresponding to Pot-Free Signals. | |
Closed Loops | Simple Closed Loops | Tag No. Description /Range/ Units/Alarm Limits / Controller Action as per Point database. Measured variable on 0, 50 & 100 percent of input variation across the Loop Range. Forced output on 0, 50 & 100 percent and observation at Marshaling cabinets. Check for the PID tuning parameters. Ensure the AOT signal is inverted (FO) or else not inverted (FC) wherever required. Check for the Loop operation from Graphics. |
Test 6: Engineering / Operator station Functionality
Purpose of Test
To demonstrate various features of the Engineering and Operator station.
Test Procedure
Verify, that it is possible to monitor and operate Process types of equipment through Graphic displays.
Verify that it is possible to change set point, mode, output, etc. for control loops.
Create a process alarm and verify that it is available on Engineering / Operator station.
Create a process event and verify that it is available on Engineering / Operator station.
Create a system alarm by shutting down any node and verifying that the system alarm appears on the system alarm display.
Test 7: Controller CPU Redundancy
Purpose of Test
To demonstrate CPU redundancy for Controller Node.
Test Procedure
Open the Graphic page and faceplate for a control loop on the operator station.
Press the INIT button on the primary controller (controller having indication on controller front panel)
Verify that the Backup controller takes over seamlessly (the backup controller will have the indication changed to on the controller front panel)
Verify there is no loss of control on the operator station.
Verify alarm on operator station.
Allow failed controller to boot.
Test 8: Power Supply Redundancy
Purpose of Test
To demonstrate the redundancy of Power supplies used for AC800M controllers.
Test Procedure
Open Graphic display on operator station. Feed mA to one of the Analog tags/objects present on the graphic.
Switch off one of the Power supplies. Verify that there is no interruption and fed signal data is still available on the operator station and if so, switch on the power supply and perform the same operation on the second power supply.
Verify power supply failure alarm on operator station.
There should not be any failures in the subsystem, and it should not cause any disturbance to
the uninterrupted operation of the system.
There should not be any interruption in the operation of the controller subsystem.
Test 9: Diode O-ring Checking
Purpose of Test
To check for Diode O-ring failure and redundancy.
Test Procedure
Switch off one of the power supplies & verify that the same power supply module is not getting power through the Healthy power supply module & confirm that reverse voltage is not available.
Test 10: Controller CPU Loading
Purpose of Test
To verify that controller CPU loading is within the permissible limit.
Test Procedure
The procedure will be different as per OEM
Test 11: Serial Communication Interface Check
Purpose of Test:
Verify that all modules are in running condition.
Verify that all the tags are configured as per the customer Modbus list.
Procedure
Check the functionality by establishing communication with Mods can. Simulate and verify that the data is reading in the engineering station.
Test 12: Logic Check
Purpose of Test:
To check the logic functionality as per customer input documents like control narrative, cause-and-effect matrix, safe chart, and alarm and trip schedule.
Test 13: System Diagnostic Function
Purpose of Test
To check the configuration, system diagnostic of Process and Safety System and view the status in graphics.
EndNote
I hope now you have an idea about the Site Acceptance Test (SAT) Procedure of PLC/DCS.
From my side, I will try to cover all the topics in my next articles. So, stay connected.
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