Pro
8 min
CCST 25 — Lockout/Tagout (LOTO) PLC Interlock
ccstsafetyLOTOinterlock
Ready to build this?
Sign up free — no credit card required. This scenario requires the Pro plan.
Sign up to play this scenario →Already have an account? Log in
Briefing
During maintenance, a LOTO_KEY switch must disable all motion outputs. Write the interlock so that CONVEYOR_FWD can only run when LOTO_KEY is FALSE (energy isolated).
Objectives
- CONVEYOR_FWD is blocked whenever LOTO_KEY is TRUE
- Normal start/stop logic still works when LOTO_KEY is FALSE
Hints
- Series LOTO_KEY (as NC contact / NOT LOTO_KEY) in the CONVEYOR_FWD rung
- CONVEYOR_FWD := (START OR CONVEYOR_FWD) AND NOT STOP AND NOT LOTO_KEY
I/O Table
Inputs
STARTStart push-button
BOOL · %I0.0
STOPStop push-button
BOOL · %I0.1
LOTO_KEYLOTO key switch (TRUE=locked out)
BOOL · %I0.2
Outputs
CONVEYOR_FWDConveyor forward drive
BOOL · %Q0.0
Your program will be tested against:
All test cases run automatically when you submit. Assertions are hidden until you pass.
- #1Conveyor runs normally
Conveyor runs normally
- #2LOTO key blocks start
LOTO key blocks start
Related scenarios
Ready to build this?
Sign up free — no credit card required. This scenario requires the Pro plan.
Sign up to play this scenario →Already have an account? Log in