Configuring Redundancy

In order to support Plant SCADA redundancy, at least two I/O devices need to be configured for the same PLC, i.e. one as Primary and all others as Standby. While the primary I/O device services Plant SCADA requests, all standby I/O devices are polled for their status every configured WatchTime to determine whether they are online.

Both the Primary and Standby devices will be offline if both have the same inoperable status condition. All tags in the system for that unit would be #COM.