If you cannot go to .NET 4.5, but need to stay with .NET 3.5 or 4.0, then the latest QuickOPC version that supports it is version 5.23. Just installing a different version does not influence the app - it needs to be rebuilt.

If you decide to use version 5.23 and don't have it at hand, let me know here and I will send you the download link by email, because it is no longer publicly available. We are also no longer committed to support 5.23; we only support the versions for .NET 4.5+. Each version has a built-in trial license, but for production use, from 5.12 it would be a paid license upgrade.

Best regards

1) The applications on the other machines also uses QuickOPC Classic5.12.
2) Two applications running in Windows server 2008 machine and other applications in Windows 7 machine. The error raises from the Windows 7 machine.

I will compare the DCOM configuration.

Will the .NET 3.5 application compiled using QuickOPC classic 5.12 run in the client machine installed with QuickOPC 5.3?

Are the other applications on other machines also implemented using QuickOPC, or something else? If they are using QuickOPC, then I think there must be some difference in the DCOM settings on the 6th machine. In such case, start DCOMCNFG and compare everything carefully - especially the Default settings for the machine, and the Limits. Also, do the machines have the same version of Windows, or different?

Try experimenting with certain settings: www.opclabs.com/forum/connections-reconnections-com-dcom/124...-remote-machines-via-code#1392

Note that the QuickOPC version you have is quite old, that may be a factor as well.

Best regards

Thanks for quick response.

I haven't run under VisualStudio, it run as Standalone application in production machine.

I have reviewed the link, but it was not my case, because I haven't update the TOP server.
Moreover, the TOP server is connected with 6 client application from 6 machines. I got the error(Exception from HRESULT: 0x80040202) from the application in 6th machine, the other 5 applications are working fine without any error.

Also, the Demo Application(.NET) reads and subscribes the values without any error in 6th machine.

Hello

Have you read this? support.softwaretoolbox.com/app/answers/detail/a_id/1358/~/i...-try-and-connect-to-the-server .

Also, are you running your app under Visual Studio? Can you try it outside VS?

I have written VB.NET application to read and subscribe the OPC tag values from the remote OPC server(SWToolbox.TOPServer.V5) using QuickOPC-Classic 5.12.1308.1. The DCOM setup is configured in both client and server machine.

Code:

The following error is raised while reading and subscriping the OPC tag.

ErrorMessage : Exception from HRESULT: 0x80040202
ErrorCode : -2147220990

Note:
1) I have tested the connection with server using Demo Application(.NET) in the client machine. It reads and subscribes the values without any error.
2) The client machine is connected using Wireless Network.