Monitoring Discrepancy Error - Input Group 1

What does FB MON Bit 0 mean?

A discrepancy has been detected between the channels of input group 1 in the FB MON function block. This means the redundant inputs are not switching in sync or are reporting different states, indicating a potential sensor fault, wiring issue, or incorrect timing that could compromise the monitoring function, leading to a safety stop.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Review the discrepancy time parameter for input group 1 in the FB MON configuration; adjust if the application legitimately has different timing requirements.

2. 4

   Monitor the individual input channels for group 1 in real-time using diagnostic tools to observe their switching behavior and identify which channel is deviating.