Configure OPC server failover

Configure PI Interface for OPC DA to fail over to another OPC server in the event it loses connection to the original OPC server.

1. In PI ICU, go to the OPCInt Failover > Server Level page and enter the node and name of the other OPC server.

   This basic configuration triggers failover only when PI Interface for OPC DA loses connectivity to the OPC server.

2. Optionally, create a string PI point to track the active OPC server. Assign the PI point to an unused point source.

   In PI ICU, go to the OPCInt > Failover > Server Level page and enter the PI point name in the Current Active Server Tag field. To display the value of the point, launch PI SMT and use the Data > Current Values feature.

   When failover occurs, the value of this point changes to the name of the currently connected OPC server. The archive of these changes enables you to view failover history.

3. To verify that failover occurs when connectivity is lost:

   1. Start both OPC servers, then start the interface.

   2. Use PI SMT or the pigetmsg utility to check the AF SDK log on the Data Archive node for messages that verify successful startup.

   3. Stop the currently active OPC server and check the SDK log to confirm that the interface has switched to the other OPC server.

   4. To switch back to the first OPC server, restart it, stop the second server, and check the SDK log or the value of the PI active server point, if defined, to verify that the PI OPC interface has switched back to the first OPC server.