Festo Compact Performance CP-FB6-E Manual page 47

2. Commissioning
If the message "PF periphery fault" occurs when the
operating voltages are switched on (pin 1 of the field
bus node), the operating voltage is probably not
switched on at pin 2. This will lead to an error message
because of the factory setting of the DIL switch.
Recommendation.
If the safety concept of your machine/system permits,
commission the CP system with both operating voltages
(pins 1 and 2), but without compressed air.
In this way, you have the possibility of testing without
the risk of undesired reactions.
2-18
CP FB6-E 9809c