Cause : FBA A communication comes when cyclical communication between the supply unit and fieldbus adapter module A or between PLC and fieldbus adapter module A is lost.

1. Check status of fieldbus communication. See user documentation of fieldbus interface.
2. Check settings of parameter groups 150 FBA, 151 FBA A settings, 152 FBA A data in and 153 FBA A data out.
3. Check cable connections.
4. Check if communication master is able to communicate.