Applies To:
  • CitectSCADA 1.00, 1.01, 1.10, 1.11, 1.20, 2.00, 2.01

Question: Is the order of the [Client] Primary and Standby important on a Standby server? 

The order of the Primary and Standby server names under the [Client] section is important and should be setup as per the online help.

The Client section tells a Citect client which server it should connect to first. If it cannot find that server, it will try to connect to the other server. However if a Citect is itself a server, its local client will always connect to itself and ignore the Client section. This is because whenever Citect tries to connect to a server, it will connect to a local server if one is available. This improves performance. Therefore if you have the client section setup incorrectly, the local clients will still work correctly.

However, the Client section is also used by servers to talk to their redundant server. If the client section is incorrect, the server will not be able to find the redundant server and some of the redundant operations will fail. An example of this is that if you acked an alarm on the Standby server, the same alarm would not be acked on the Primary server.