Runnable simulator field guide
Conveyor stop-delay PLC scenario: test checklist
Direct answer
The learner can implement and test the run-on condition before, at and after the delay boundary and explain what cancels or resets it.
Written for pLC beginners practicing a delayed conveyor stop while preserving stop priority, feedback, timing evidence and predictable restart behavior.
Scenario setup
Process reason for run-on, start and stop requests, conveyor permissives, motor command, run feedback, timer type, preset, cancellation, reset and restart policy.
I/O and state map
Operator request through PLC state and timer to motor output, mechanical run-on, material clearing, feedback and final stopped evidence.
Normal run
Start, normal run, stop request, declared run-on interval and confirmed stop repeated from a clean state.
Boundary run
Stop at zero, just before preset, exact preset, start during delay, permissive loss, feedback loss, power return and repeated stop.
Injected fault
A requirement, timer-state, time-base, scan, priority, cancellation, output-owner or feedback mismatch.
Target check
The scenario regression-tested before adaptation to target conveyor and safety requirements.
How do you program a conveyor stop delay?
Define the process reason, latch only the necessary run-on state, start a nonretentive interval at the stop request and make the final motor command obey higher-priority protective conditions.
What should happen if start is pressed during the stop delay?
The requirement must state whether the delay cancels, the conveyor remains running or a new cycle is rejected; test that choice explicitly.