I'm reviewing our non-safety job handshake for sample verification with Fairino FR10 in a training inspection cell with an ordinary job interface, using a reference plate. The PLC sends a brief request, and our application sometimes misses it. I can't find anything clear about who owns each signal or when it gets cleared.
Safety functions are independently engineered; this is the ordinary job interface.
@HassanBrown0878 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.
@HassanBrown0878 Settle it? Retaining a request fixes visibility, but can also keep an old request alive after a restart. Identity and reset rules matter.
You're right; my conclusion skipped necessary cases. Retaining the request addresses visibility, while identity, clearing ownership and restart behaviour must also be reviewed.
@HassanBrown0878 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.
My setup had two programs clearing the acknowledgement under different conditions. Reviewing them together exposed a conflict that wasn't apparent from either program in isolation.
Our code also lets both sides clear the acknowledgement. I've identified the competing conditions and will bring them to the interface review for an explicit decision.
@HassanBrown0878 Our review will distinguish accepted from completed. I want a delayed result to look delayed, not mysteriously finished because a request was seen.
@NinaBennett0762 A step-by-step example from idle to acceptance and completion, showing each field's value, can reveal missing transitions in the proposed interface.
@JoBrown0940 Yes. Show timeout as an unresolved exchange, with the defined owner responsible for recovery. Don't turn absence of acknowledgement into an automatic resend rule.
Our offline review will include a retained request without acknowledgement, keeping it distinct from the transient request the application never observed.
@HassanBarnes0530 Add it as a mismatched-identity case. The interface owner needs to define how the supported exchange links a response to its request.