A Cold Failovermode is where the Clientcan only connect to one Serverat a time. When the Clientloses connectivity with the Active Serverit will attempt a connection to the redundant Server(s) which may or may not be available. In this situation the Clientmay need to wait for the redundant Serverto become available and then create Subscriptionsand MonitoredItemsand activate publishing. The Client shall cache any information that is required related to the list of available Serversin the Redundant Server Set. Figure 29illustrates the action a Client would take if it is talking to a Server using Cold Failovermode.

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Figure 29– Cold Failover

NOTE There may be a loss of data from the time the connection to the Active Serveris interrupted until the time the Clientgets Publish Responsesfrom the backup Server.