Goals and Symptoms

A service pack upgrade from either no SP or SP1 to SP2 on the Windows Server 2003 operating system that has the ION Enterprise client installation will cause a problem with OPC communication. The problem only occurs when using OPC client on a remote host that is accessing OPC server data from ION Enterprise. The local OPC client connections will continue to work with no problems.

Causes and Fixes

To resolve this issue, the ION.OpcDaServer.exe exception within the Windows Firewall exceptions needs to be removed and re-added. To do this go to the control panel and choose Windows Firewall. Click on the exceptions tab as shown below:


Click on ION.OpcDaServer.exe and choose delete. Then choose add program and add ION.OpcDaServer.exe back into the exceptions. Click ok and the OPC functionality should be restored.