request bit with two owners

I've inherited a UR5e training bench where the PLC sets an inspection request and the PC sometimes clears it, except there's also a PLC timer clearing it. Lovely little mystery. This is the ordinary job interface, separate from the engineered safety functions. Before anyone stretches the pulse, I'd like to map who sets, acknowledges and clears each signal; has anyone got a sensible way of reviewing that with both programmers in the room?