Robot PLC Handshake

Briefing

Implements the standard Rockwell/ABB PLC-to-robot handshake protocol. The PLC signals PLC_READY when all preconditions are met. When a part arrives and the robot is ready, the PLC pulses CYCLE_START. The PLC then waits for ROBOT_CYCLE_DONE to confirm completion before incrementing a cycle counter and de-asserting CYCLE_START. A robot fault latches ROBOT_FAULT_LAMP and inhibits new cycle starts.

Objectives

• PLC_READY asserts when RUN_BIT is set and no robot fault is active
• CYCLE_START pulses (one scan) when PART_AT_ROBOT AND ROBOT_READY AND PLC_READY
• SAFETY_OK mirrors the absence of a robot fault (NOT ROBOT_FAULT)
• ROBOT_FAULT_LAMP latches on ROBOT_FAULT and clears only via STOP_PB
• Cycle counter increments on each ROBOT_CYCLE_DONE acknowledgement

I/O Table

Your program will be tested against:

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

1. #1PLC_READY asserts when running and no fault

   START_PB energises system; PLC_READY goes high, SAFETY_OK also high

2. #2CYCLE_START pulses on PART_AT_ROBOT + ROBOT_READY

   With PLC_READY high, presenting a part and robot-ready signal fires CYCLE_START

3. #3ROBOT_FAULT latches ROBOT_FAULT_LAMP and drops SAFETY_OK

   ROBOT_FAULT drops SAFETY_OK and latches fault lamp; STOP_PB clears it