Cause : Motor 1 field exciter communication loss comes when communication error occurs, it can disrupt the drive's operation and prevent it from functioning correctly.

F516 M1FexCom fault in ABB DCS800 drive indicate Motor 1 field exciter communication loss. This means a communication error between the drive and the M1FexCom module.

1. Check flat cable connections between SDCS-CON-4 and SDCS-PIN-4.
2. Check auxiliary voltage for integrated and external field exciter.
3. Check DCSLink cable connections.
4. Check DCSLink termination set dip switch S1100:1 = ON (DCF803-0016, DCF803-0035 and FEX- 425-Int).