Applies To:
  • CitectSCADA v6.0, v6.1 
  • Vijeo Citect v6.0, v6.1

On my pre-v7 system I have a redundant RATIO server setup as well as a configured time server on the primary machine. I have followed Q3725 to configure IP addresses for my servers, however I am having difficulties getting my display clients to properly connect to both servers through the IO port (port 2078). All the other ports seem to connect fine. 

When the primary server is online (and the standby server is offline) the client will connect to all the primary server ports correctly, but when the standby server is also online the client connection through the server IO port (2078) will only persist to the standby server. The connection between the client and the primary IO port gets dropped. There should be a connection each from the display client to the primary and standby server through port 2078.

My server/computer names are as follows:
 Primary Server     syd-d-weiching
 Standby Server  syd-d-cs7556
 Display Client   syd-d-wcpc

Doing a "netstat -na" on my client machine when both servers are online shows the following:

Proto Local Address Foreign Address State
TCP syd-d-wcpc:1046 ESTABLISHED
TCP syd-d-wcpc:1047 ESTABLISHED
TCP syd-d-wcpc:1048 ESTABLISHED
TCP syd-d-wcpc:1049 ESTABLISHED
TCP syd-d-wcpc:1050 ESTABLISHED
TCP syd-d-wcpc:1051 ESTABLISHED

I would expect to see two connections via port 2078, such as:

Proto Local Address Foreign Address State
TCP syd-d-wcpc:1038 ESTABLISHED
TCP syd-d-wcpc:1039 ESTABLISHED
TCP syd-d-wcpc:1040 ESTABLISHED
TCP syd-d-wcpc:1041 ESTABLISHED
TCP syd-d-wcpc:1042 ESTABLISHED

What needs to be changed in the configuration?

This behaviour was seen only when the time server name under [Time]Name in the citect.ini was set to the same as the primary and standby server name configured in the citect.ini parameters [IOServer]Name and [Server]Name. When parameter [Time]Name changed to a unique name, then a connection was correctly established to the primary server as well as the standby.

In v7 and above IP addresses of servers are configured in the project rather than the citect.ini file. In this version the time server is still configured through parameters in the ini file.

Additionally, v7.10 introduces a Time Synchronisation Service where configuration of Citect time servers are configured in design time environment and [Time] ini parameters are no longer required.

 Time Server, netstat, redundancy, IOServer, connection, port