This article is useful if TopView connects to your OPC server when run interactively, but cannot connect to remote OPC Server(s) when you run TopView as a Service.
Interactive applications (non-Service) run under the account of the logged in user, services run under the configured logon account for the Service. Ensure TopView is running under the expected user account, especially after launching TopView from an elevated Configurator application.
The task manager’s process details will show the user account under which a process is running. Look for TopView.exe or TVConfig.exe.
OPC Servers use DCOM for the remote connection and often grants or refuses incoming connections from TopView based on the user account. The solution is to configure DCOM to allow connections from the TopView Service Logon account. Please see the following page for DCOM configuration information.