There was a little fix in the handling of the Modbus TCP slave in easYgen-3000XT, and this came with version 2.10

That was initially a little bug. easygen did not close the TCP connection when there is no more traffic.

Else in multiple Modbus network, if easYgen would leave all possible 5 sessions alive all the time and there is actually no traffic through these TCP connections, then the next (6th) TCP connection/request could not be served.

With v 2.10 we fixed that.

Suggestion, if that is an issue on customer side:

If you want one TCP connection to be active all the time, you need to keep it running by e.g. reading a value cyclically every 1 - 2 seconds, so the easYgen keeps that connection open.
We think, with the PLC that should not be an issue to establish such a cyclic read request.