Error Handling - Festo CPX-FB39 Description

4 Diagnostics and error handling
4.6

Error handling

With the following malfunctions, the behaviour of the CPX terminal depends on the configured beha­
viour of the master module and the parameterised fail-safe setting:
– Telegram failure
– stop of the master
– interruption in the bus cable.
Depending upon the configuration, the outputs (valves and electrical outputs) are
switched off (factory setting), switched on or they retain their existing status.
Further information can be found in the CPX system description (è P.BE-CPX-SYS-...).
These characteristics can be altered using the Festo Maintenance Tool (CPX-FMT) software, the control
device (CPX-MMI) or Sercos mechanisms.
Change via Sercos
• Change configuration of fallback values (è Tab. B.12 (IO_FG.SI.22 - Fallback Value Output)).
• Change configuration of fallback values (è Tab. B.12 (IO_FG.SI.02 - Configuration Of IO_FG).
Change via CPX-FMT/CPX-MMI
• Change configuration of failsafe values (è CPX system description P.BE-CPX-SYS-..., online help
with CPX-FMT software or description of control device P.BE-CPX-MMI-1-...).
Please Note
A change in the fallback and backup values via Sercos also has a corresponding impact
on the failsafe entries in the CPX system table (è Tab. B.14).
In the event of any retrospective adjustment of fallback values via CPX-FMT or CPX-MMI,
the backup value characteristics provided for in the Sercos standard no longer apply.
Warning
Accidental activation of actuators!
An incorrect status of the valves and outputs can lead to dangerous situations!
• Ensure that valves and outputs relating to the aforementioned problems are placed
in a safe condition.
Please Note
If the outputs are reset in conjunction with PLC-Stop, field bus interruption or a fault,
pay attention to the following:
– monostable valves move to the initial position.
– Double solenoid valves remain in the current position.
– Mid-position valves go into mid-position (pressurized, exhausted or closed, depend­
ing on valve type).
Festo – P.BE-CPX-FB39-EN – 1504NH – English 63