Transmission Error: Timeout (F_WD_Time or F_WD_Time_2 Elapsed) (V2 CPU)

What does 78 mean?

A transmission error due to a timeout has occurred in an AC500 V2 non-safety CPU PM5xx system, meaning either F_WD_Time or F_WD_Time_2 has elapsed without receiving expected communication. This indicates a communication failure or an incorrectly configured watchdog timer.

1. 1

   Check PROFIsafe watchdog time parameters (F_WD_Time, F_WD_Time_2) in the configuration.

2. 2

   Inspect communication infrastructure for delays or disconnections.