The PairCheck monitors contradictory feedback.
It automatically detects physically impossible states, for example:
"Cylinder 1 Front = TRUE and Cylinder 1 Rear = TRUE".
If such a conflict is detected:
the zone generates an interlock,
the automatic sequence is stopped,
the HMI displays the diagnosis "PairCheck Error – Contradictory feedback".
The PairCheck operates continuously, independent of the switch position.
This eliminates one of the most common sources of error in industry – faulty or incorrectly wired limit switches.
