Modicon Concept 984

[Latzi Marian 0]

Hi Gents, I am not familiar with Concept (familiar with Modbus however) and I was asked a question from one of my customers about an error they are getting intermittently : "984 - Not logged in or a user is logged in on another port Please return to offline mode to re-login to the PLC" Any idea what this is or where I could do some research on this ? I only have a screenshot of this error so I am not sure what the software they are using is but I think hey are running Concept on a WIN 98 VM

[Crossbow 296]

Typically means someone else is connected from another PC.