QUESTION:
Is the Insert/Remove function supported for I/O modules of the ET200M with S7 software redundancy systems?

ANSWER:
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.

Explanation:

• 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.

Keywords:
Module replacement, Module change