That example seems like alot of overhead to do this and the config below allows the operator to switch at anytime because the not selected loop(s) is following what the downstream is doing so there will be no bump:
- BKCAL to PID1 (OUT1) is value and status from downstream PID3 BKCAL
- BKCAL to PID2 (OUT2) is PID3 BKCAL value with status of 204 (GoodCascade NotInvited) plus the sub status from the downstream PID3 BKCAL (NotLimited, LowLimited, HighLimited, Constant) when PID3 BKCAL has Status of GoodCascade, otherwise it passes the status unchanged.
- PID3 CAS_IN (OUT3) is value and status from PID1 OUT (IN3)
When PID1 is NOT selected:
- BKCAL to PID1 (OUT1) is PID3 BKCAL value with status of 204 (GoodCascade NotInvited) plus the sub status from the downstream PID3 BKCAL (NotLimited, LowLimited, HighLimited, Constant) when PID3 BKCAL has Status of GoodCascade, otherwise it passes the status unchanged.
- BKCAL to PID2 (OUT2) is value and status from downstream PID3 BKCAL
- PID3 CAS_IN (OUT3) is value and status from PID2 OUT (IN4)
If both loops are to control (modulate it's output) while the selection is made, then this logic changes slightly. You will need something very similar to logic shown but I believe the status logic would use a 208 (GoodCascade NotSelected) instead of 204.
Regards,
Matt