Our application sometimes misses the PLC's brief request for part inspection.
I'm reviewing that ordinary, non-safety handshake for Universal Robots UR5e in a PLC-coordinated fixture inspection cell, with a sample housing in the setup.
Signal ownership and clearing conditions aren't clearly documented.
The safety functions are independently engineered and separate from this job interface.
@DanielChen1174 Our trace shows it rising and falling between two polls. The PLC clears it without an observed acknowledgement. No wonder the application misses it.
Draft one writer and clear conditions for each field, then review a request retained until matching acknowledgement with the interface owner. That should settle the handshake offline.
@WillBennett0748 You're right; my conclusion skipped necessary cases. Retaining the request addresses visibility, while identity, clearing ownership and restart behaviour must also be reviewed.
@DanielChen1174 Should I record readers as well as the single writer? Our existing phrase used by PLC doesn't distinguish setting, reading or clearing a field.