Pneumatic Press Cycle

Briefing

A pneumatic press with a safety guard. The guard must be closed before the cycle can start. Pressing START_PB energises the EXTEND_VALVE, pushing the ram down. When EXTEND_LS confirms the ram is fully extended, the extend valve de-energises and the RETRACT_VALVE energises, pulling the ram back. When RETRACT_LS confirms retraction, the cycle completes and CYCLE_COMPLETE_LAMP pulses. Opening the guard mid-cycle drops all valves immediately.

Objectives

• GUARD_CLOSED must be true before START_PB is effective
• START_PB energises EXTEND_VALVE; RETRACT_VALVE stays off
• When EXTEND_LS true: EXTEND_VALVE drops; RETRACT_VALVE energises
• When RETRACT_LS true: RETRACT_VALVE drops; CYCLE_COMPLETE_LAMP pulses
• Opening guard mid-cycle (GUARD_CLOSED goes false) drops all valves immediately
• ESTOP drops all valves immediately

I/O Table

Your program will be tested against:

All test cases run automatically when you submit. Assertions are hidden until you pass.

1. #1Guard must be closed before cycle can start

   START_PB with guard open does nothing

2. #2START_PB with guard closed energises EXTEND_VALVE

   Normal cycle start: EXTEND_VALVE energises, RETRACT_VALVE stays off

3. #3EXTEND_LS transitions to retract phase

   When EXTEND_LS fires, extend valve drops and retract valve energises

4. #4RETRACT_LS completes cycle and lights CYCLE_COMPLETE_LAMP

   Full cycle: extend → retract → CYCLE_COMPLETE_LAMP on

5. #5Opening guard mid-cycle drops all valves

   Guard opened during extend phase immediately drops EXTEND_VALVE