My colleague is questioning if these could have been cause by something else. To verify can you clear the logs and check if the only come back after the error occurs.
Can you verify that you can not read and write from the Ethernet side of the device? If you can not this might indicate the issue isn’t the Profibus master with the issue and we might need to investigate other parts of the configuration having issues.
Where we have not seen this issue before but it is happening at multiple locations for you it might be helpful to gather some info on each of the setup and see if we can find any correlations with the setup. Do you have any installations that are not have the issue? It might might help to compare the setups to see if we can track down what is different. What would be important here would be what Firmware is on all of the anybus device, Serial numbers, info on the Bus configuration. If we can identify what is common among the setups with the issue this should help us identify the root cause.