Redundancy is a broad concept, as explored in our Demystifying Redundancy Blog. In this post, we narrow the focus on how to manage redundant OPC servers—a critical topic for ensuring reliable process communications to your HMI, SCADA, MES, Historian, etc. Redundancy is crucial because it ensures continuous operation and data integrity in the event of system failures, minimizing downtime and potential losses.
Simply deploying two OPC servers connected to your PLCs doesn’t make them redundant. We're sometimes asked about having the two OPC servers communicate and decide when to failover. That sounds good but has a flaw. If the client loses network connection to one OPC server but the two OPC servers are still communicating, and the HMI/SCADA doesn’t have any internal failover mechanism, then no failover will occur.
