Pro
10 min
CCST 11 — Diagnose: NO/NC Swap (Repeat)
ccstdiagnosticsNO-NCmotor
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
Motor refuses to start. Field wiring confirmed correct. Identify and fix the logic fault in the ladder: the STOP_PB contact type is wrong.
Objectives
- Use scan-cycle highlight to find the blocking contact
- Identify the NO vs NC mismatch on STOP_PB
- Fix the ladder; verify motor starts and seals in
Hints
- Switch to slow-scan and watch contacts in slow mode
- A stop button in a 3-wire circuit is normally-closed
- In IEC: NOT STOP_PB is the NC equivalent
I/O Table
Inputs
START_PBStart button
BOOL · %I0.0
STOP_PBStop button (NC)
BOOL · %I0.1
Outputs
MOTOR_CONTACTORMotor contactor
BOOL · %Q0.0
Your program will be tested against:
All test cases run automatically when you submit. Assertions are hidden until you pass.
- #1Motor starts
Motor starts
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