Relays Offline In Runtime

Relays Offline In Runtime

Dear Support,
We are using DNP3-Process gateway over serial communication. Our network include 50 relays out of which 3 relays are showing offline on Gateway Runtime. In actual Relay is reachable(pingable) and from other workstation on the same network it shows online on Zenon Runtime. The only problem for these 3 relays are on Gateway Runtime.
Please suggest what could be the possibilities for this problem.

This is a migrated post! Originally posted on 28.01.2015 by user junaid. Please be aware that information can be outdated.