Festo CPX System Manual page 164

B. Parameters and data of the CPX terminal
System parameter: Fail safe (reaction to communication faults)
Function no. 4402
Description Determines the signal status which the outputs/valves are to assume in the
event of fieldbus communication faults, e.g. in the event of:
In the following case, the channel−orientated Fail Safe settings (module para
meters Fault mode and Fault state) are reset automatically for safety reasons in
order to avoid undesired signal states.
Bit Bits 0, 1
Values Fail safe
Bit 1 0 Description
0 0 Reset all outputs (presetting)
0 1 Hold last state (retain signal status)
1 0 Assume fault mode
Note The Fault mode status is set with the channel−specific module parameters.
Further information on this parameter can be found in section C.3.
Tab. B/5: Fail safe
B−10
Communication failure (fieldbus interruption, PLC/IPC failure)
Communication stop.
When changing from Assume fault mode" to Reset all outputs" or to Hold
last state".
[Fail safe]
[Reset outputs]
[Hold last state]
[Assume fault mode]
Festo P.BE−CPX−SYS−EN en 0902e