The following question was asked on Automation & Control Engineering Group on LinkedIn. Thought I would repost here with link to that posting if anyone has insight.

"In my present project, I have a redundant Ovation controller to be communicated with a redundant Siemens controller using modbus IEC104 with hot-hot configuration. For some reason, we have two kind of configurations. Both Siemens and ovation are master and slave. When ovation is master (siemens slave) communication works fine. But when siemens is master (ovation slave) only one ovation slave gives respond. Another one seems actively reset connection. I have tried using other master simulator instead of Siemens to communicate with ovation and it works fine. Try with Siemens again and it fails. Any idea how to solve this issue?"

https://www.linkedin.com/groups/1967039/1967039-6172439748104282114