I am using OPC Labs QuickOPC 5.31 in VB.NET application to read the OPC tags from the Top server. The application and the Top Server are located in different machine. DCOM is configured in both machine.
I have used the ProgID (SWToolbox.TOPServer.V5) to connect the Top server.
EasyDAClient.ReadItemValue("Machine-PC", "SWToolbox.TOPServer.V5", "TagName")
It was working fine for past 3 months, now the application throws the errror.
Error : No method available to convert ProgID to CLSID.
ErrorCode: -1073442759
If I change the ProgID(SWToolbox.TOPServer.V5) to ClassId ({r466fbf7-c92d-341d-84be-3476123deccd68}) to connect the TOPserver, it works fine.
EasyDAClient.ReadItemValue("Machine-PC", "{680dfbf7-c92d-484d-84be-
06dc3deccd68}", "TagName")
Another OPC client application running on the same machine as Top server located, it uses ProgID (SWToolbox.TOPServer.V5) to connect the Top server, it also working fine.
The error is only from the remote OPC client applications which are using the ProgID to connect the TOPServer.
Let me know the reason for the error?