Issue
If a Modbus IP server goes offline it will slow the polling of other operating servers, how can this be prevented?
Environment
Modbus TCP/IP X-Driver
Cause
When the Client Modbus IP XDriver polls points from a Server that is offline or not communicating it will time out slowing the polling of other online devices.
Resolution
Create a "Remote Device Status Point" (Function code 102) for each of the Servers on the system. This point will return a value of 1 when the server is communicating, 0 when it is not connected.
If a server is known to be offline or switched off this point can be set to a value of 2 to stop it polling that server for data. This allows the other servers to continue to be polled without any time out delays from every point on the offline server.