For non-transparent Redundancy, OPC UA provides the data structures to allow the Client to identify what Servers are available in the RedundantServerSet and also Server information which tells the Client what modes of Failover the Server supports. This information allows the Client to determine what actions it may need to take in order to accomplish Failover. This information is specified in NonTransparentRedundancyType ObjectType defined in OPC 10000-5.
For non-transparent Redundancy, the Servers will have unique IP addresses and unique ApplicationUris. The Server also has additional Failover modes of Cold, Warm, Hot and HotAndMirrored. The Client shall be aware of the RedundantServerSet and shall be required to perform some actions depending on the Failover mode. These actions are described in Table 111 and additional examples and explanations are provided in 188.8.131.52.5.2.for Cold, 184.108.40.206.5.3 for Warm, 220.127.116.11.5.4 for Hot and 18.104.22.168.5.5 for HotAndMirrored.