PROFINET Forum

FredB wrote: ↑11 May 2026, 09:19 Hello,

I am currently testing our IOC with ARTTester (version V2.46.2.202).

I observed the following behavior during MRP tests:

- When running "MRP On-Off - Client" followed immediately by "MRP Check - Client", the test passes successfully.
- However, when running "MRP Check - Client" alone after a power cycle of the IOC, the test fails.

The issue seems related to the MRP_Role field in the read frame (index 0x8050 – PDInterfaceMrpDataReal).

Observed value:
- Media Redundancy Disabled (0x0000)

Expected value:
- Media Redundancy Client (0x0001)

(This expected behavior was confirmed by comparison with a Siemens device.)

I am unsure why this discrepancy occurs and why our implementation reports an incorrect value after a power cycle.

I have reviewed the relevant standard documents, including GSDML specifications and guidelines, but I could not find a clear explanation of the expected behavior or usage of the MRP_Role field in this context.

Could anyone clarify:
- how this field is expected to be set,
- and where the relevant specification details can be found?

Thank you in advance for your support.

Kind regards