Runnable simulator field guide
Gas compressor ESD PLC scenario: test checklist
Direct answer
The learner can map each simulated initiating cause to the required stopped state, preserve first-out evidence and prove that reset does not restart unavailable equipment.
Written for process-control learners studying permissives, trips, first-out indication, shutdown outputs, depressurization boundaries and deliberate restart.

Scenario setup
Process hazard, operating states, start permissives, trip causes, first-out, shutdown command, recycle or blowdown boundary, valve and motor feedback, alarm, reset and restart authorization.
I/O and state map
Pressure, temperature, vibration, gas or operator demand through shutdown logic to driver stop, valve commands, process response, feedback and retained event evidence.
Normal run
Every declared trip produces the intended stopped modeled state, records first-out cause and blocks restart until all conditions and deliberate actions exist.
Boundary run
Simultaneous trips, failed stop feedback, stuck valve, sensor bad quality, communication loss, reset held, cause returns, controller restart and power return.
Injected fault
An initiating-condition, input, vote, logic, output, final-element, process, feedback, event or restart mismatch.
Target check
The real cause-and-effect, protection layers and shutdown sequence engineered and validated by qualified teams on target equipment.
What should a compressor ESD sequence do?
It should execute the approved cause-and-effect response, stop or isolate the required equipment, preserve first-out evidence and prevent restart until defined conditions are satisfied.
Why retain the first-out trip?
Later effects can trigger many alarms; first-out evidence helps distinguish the initiating condition from the shutdown consequences.