WAGO -I/O-IPC-C6 Manual page 292

292 Appendix
Description
In principle, the PROFIBUS redundancy function must be enabled via the
"Redundancy" module parameter in the CoDeSys control configuration.
In the start-up phase of the IPCs, one IPC is automatically started as an active
PROFIBUS master and one IPC as a passive PROFIBUS master. The active
master established communication with the slaves and the passive master monitors
the communication of the active master. If the communication of the active master
with the slaves fails, the passive master automatically takes over.
This functionality is available even without a function block.
In case of error, the DPM_REDUNDANCY function block switches between the
"active" and "passive" PROFIBUS operating modes.
The module must be activated via the ENABLE input. The current mode of the IPC
is output to the MASTER_MODE output.
If the active master fails, the passive master takes over communication and also
sets the RESET_MASTER output. This output is connected to the REBOOT input
of the failed master via MODBUS variables or hardwired. If this signal is present
for min. 100 ms, the master executes a restart as the passive master.
Communication monitoring is now performed in reverse.
Please note the following during use:
1. If an internal error in processing the PLC problem leads to failure of the active
master, the PLC program cannot detect the REBOOT input. In this case, the
reverse monitoring mechanism is not carried out automatically.
2. Redundancy monitoring is not available via the CoDeSys when the passive
master is in the logged in state.
3. The monitoring mechanisms is activated 5 seconds after startup of the IPC.
4. The reboot function is executed 1 second after failure detection of the active
master. If the failed master is integrated again in PROFIBUS communication
within this time, bus communication will fail.
5. If an IPC is not physically connected to the PROFIBUS in the startup phase
and is only integrated at a later time, PROFIBUS communication temporarily
fails for a few seconds. The monitoring function is then activated.
6. When redundancy monitoring is used, a baud rate > 1500 kbit/s may not be
selected.
WAGO-I/O-SYSTEM 750
758-874/000-131 WAGO-I/O-IPC-C6
Manual
Version 1.0.0