Some user replace Quantum NOE by NOC, which is always used for communicating with SCADA or 3rd party's device as ModbusTCP server.
The communication may fail after the replacement, why can't the connection establish?
The most likely cause of this issue is the UnitID in the client setting as 255. UnitID255 for NOE is normal UnitID, but for NOC, it is used for Diagnostic in NOC module itself.
There is a note in NOC's user manual. Please refer to the attachment.
The solution is to change the UnitID from 255 to 0~254.

Released for:Schneider Electric India