Applies To:
  • CitectSCADA

A typical scenario is where the OPC server and client are not on the same PC (hence requiring you to configure DCOM) but where they are also not part of the same Domain, ie only a "Workgroup".

This has additional requirements on top of the usual details of DCOM configuration:

Both the server and client PC need to be logged in and setup with the exact same username and exact same password. Then apply the DCOM security settings to both the server and the client PC's.

Also if using Windows XP service pack 2 the final step is to alter the default security settings for local accounts:
Click on Start/Control Panel/Administrative Tools and open the Local Security Settings window. Expand the tree view and select Local Policies\Security Options in the left hand pane. In the right hand pane, scroll down and select Network Access: Sharing and security model for local accounts. Right-mouse click and select Properties. Select Classic - local users authenticate as themselves.

There is a very comprehensive whitepaper on this subject available on the OPC Foundation's website in the whitepapers downloads section.

Title: Using OPC via DCOM with Windows XP Service Pack 2
Vesion: 1.10
Last Modified: 2006-03-30

OPC, DCOM, XP, SP2, Remote, Workgroup, Domain, dcomcnfg