The most common problems our users run into with FactorySQL often revolve around DCOM security. This is especially true when trying to access OPC servers hosted on a different machine. I just thought I’d post a few items that can help a lot:
Lots of companies have published OPC specific DCOM config guidelines. One that I just found & that I like a lot is from AscoLab, a big OPC supporter out of germany. They’ve created a CHM that you can download freely at: http://www.ascolab.com/downloads/dcom.chm
Another extremely useful tool in debugging dcom security is the ability to log dcom events in windows. You have to turn this on manually in the registry, but it isn’t too hard:
- Open up regedit
- Browse to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole
- Add the following 2 DWORD values:
After this, you need to restart the dcom programs that you’re trying to use- generally, this will either be the FactorySQL service, the OPC server, or OpcEnum (which you’ll have to find in the task manager and manually quit).
Now all authentication failures will be logged to the windows event log. Go to Control Panel> Administrative Tools> Event Viewer to view the logs.
Note: This information was taken from Microsoft knowledge base article 892500, located at: http://support.microsoft.com/kb/892500
If you have any questions about any of this, feel free to reply here. Hope it helps!