Dear sir:
I’m a beginner and would like to ask for help from the experts.
I connected to an OPC Client from Edge using the OPC DA method. The OPC Client passes tag information obtained from the OPC Server to Edge.
However, I can only get the tag names in edge but not their values. Could any expert please help me understand why this is happening?
Some OPC DA servers are buggy, and don't do "subscribe" properly. Try the [r] to see if you can do a poll read. If so, set an Ignition tag group to use OPC Reads instead of subscriptions and put the tags in this group.
I found a clue: in the OPC Client’s Distributed COM Users Properties, the Members list is empty.
What I mean is — do both computers need to have members added under Distributed COM Users Properties?
Could this be the cause of the problem?
Someone else with have to chime in. You've exhausted my knowledge of OPC DA problems and my willingness to work on anything related to Windows.
It sounds like you're hitting this problem described in the user manual:
That section references this section on how to configure DCOM settings on the Ignition machine:
I have never had to deal with COM, but the security settings described in the user manual seem very loose. I'd imagine that it could be locked down a little tighter, but start with the recommendations in that section before trying to tighten down the permissions.
It works! thanks so much, sir
