Is the Insert/Remove function supported for I/O modules of the
ET200M with S7 software redundancy systems?
No, the Insert/Remove function is not supported for I/O
modules of the ET200M with S7 software redundancy. However, there
is a way of using Insert/Remove for I/O modules in S7-400 systems
without error messages and redundancy switching. For this you must
disable automatic master switchover before removing the module to
be replaced and then re-enabling it again once you have inserted
the new module.
- If you do not disable the master switchover, an error is
reported when you remove the module, which leads to master
switchover. When you insert the new module, the second CPU would
simply be informed of an ongoing fault. So inconsistent error
messages would be in both CPUs.
- If I/O modules (in the ET200M) are inserted or removed during
operation, then OB83 is called. But this OB is not supported by the
CPUs of the S7-300 series, because it is not available in the CPU
operating system. If the ET200M is configured as standard slave in
STEP7 (via the GSD file), then Insert/Remove is possible, because
in this case it is not OB83 but OB82 that is called. This OB is
supported by all S7-300/400 CPUs (See Entry ID: 1826766).
However, since the S7 Software Redundancy package uses the "Acyclic
reading/writing of data records" function and this is not supported
by DP standard slaves (GSD), the mechanism cannot be used for
S7-300 Software Redundancy.
Module replacement, Module change