Communication/PLC Failure

A communication/PLC failure occurs where the enabler can no longer communicate over any network path to a running healthy PLC; for example network down, PLC powered down, PLC stopped or Health bit clear.

• Active PLC - the enabler updates the diagnostic points then performs a failover to the next highest ranking running Healthy PLC with the Health and active mode bits set.
• Standby PLC - the enabler updates the diagnostic points for the PLC.

The enabler then retries communications to the failed PLC at the configured heartbeat rate.