Instruction Manual

C. General information on parametrisation
C−15
Festo P.BE−CPX−SYS−EN en 0902e
C.3.2 Signal status in the event of a fault (Fail safe)
Fundamentals
With the aid of the so−called fail−safe parametrisation, the
signal status which the outputs are to assume in the event of
fieldbus communication faults, can be determined (fail−safe
status). In this way, a defined machine/system status should
be created in the event of fieldbus communication faults (e.g.
failure of the higher−order PLC/IPC).
Warning
Depending on the functions of the machine/system, the
manipulation of signal states can lead to serious personal
injury or material damage.
Use the Fail−safe parametrisation very carefully, in order to
avoid damage.
CPX parametrisation
With CPX terminals, fail−safe parametrisation can be used for:
 Digital outputs
 Analogue outputs
 Valves
By means of the system parameter fail−safe, you can globally
determine the signal status which the outputs/valves are to
assume in the event of fieldbus communication faults, e.g. in
the event of:
 Communication failure (fieldbus interruption, PLC failure)
 Communication stop