OPC quality WAITING – but quick client returns good value –
I have started to add tags to a new project and am having an issue. I have Kepware on a remote machine and have setup an OPC-DA connection. Status is returned as connected. When I try to add a SQLTag to the project from that server, I get a constant “Waiting” for quality. When I use the OPC Quick Client I can get a good quality and a valid value.
where should i start looking for the solution?
thanks
travis
What version of Ignition do you have?
7.1.8 b6247
BTW - once i added the item as a subscription in the OPC quick client, it changed to a Bad-NodeIdUnknown status and now i cannot get a good read from it. Even after I removed the subscription it wont return to a good status.
Is this the same issue that we’ve been discussing over email? It basically sounds like DCOM security problems, and that the Kepware machine isn’t able to connect back to the Ignition machine.
I provided more info in my email, but wanted to comment here so the thread wasn’t left dangling.
Regards,
Yes - i was hoping it was going to start out a simple problem, so I started here looking for input from the users group. When the solution eluded me, I contacted support via email. I have followed the instructions in your email - priviledges were not allowed on the users for the settings. I have made the changes, restarted the ignition server but cannot restart the OPC machine until later. Restarting the OPC server machine with the changes did not solve the problem.
I’ll get back with you after i have an opportunity to restart the other machine.
You shouldn’t need to restart the Kepware machine, since you were able to connect to it. The trick is to get the DCOM settings correct on the Ignition machine so that Kepware can connect back in to deliver values.
Check out this thread in the knowledge base for info about how to turn on DCOM logging, which might help, and links to whitepapers from the OPC Training Institute and Matrikon which might be helpful.
Regards,
Followed the post on that thread and ta-da! It works…read the log and poked holes in DCOM security like swiss cheese. At least it is an isolated network.
thanks
t.
Great! Yeah, you don’t know how many times I’ve heard “at least it’s an isolated network” when working with DCOM. It always feels a bit wrong to just open everything up, but ultimately, that’s what it takes. On the plus side, the future is here, so if security were a concern, you could upgrade your Kepware to the latest (for pretty cheap, I would imagine) and use UA instead, with encryption, authentication, firewalls, etc. etc.
Anyhow, glad you got it working.
Regards,
Hello everyone,
I am having a similar kind of issue. All my tags from OPC-DA server (Siemens OPC.SimaticNet) are displayed as WAITING when I run my groups. However, this happens only when I am using a trigger for data storage in MYSQL. The trigger I am using is a boolean tag and condition is Only Execute Once When Trigger is Active.
Event tab at the bottom says: Trigger did not evaluate. Source item currently has bad quality (null,waiting)
Checking the same tag with quick client shows a good quality.
When I do not use any trigger, real time values for tags are displayed as well as the values are written into database successfully.
I was evaluating FactorySQL for the same purpose and it worked very fine.
I have Ignition installed on the same machine, I am using the same OPC server from Siemens and I am connecting to the same PLC’s.
If anyone could throw some light on this weird behavior, that would be really great.
Thanks
Vishal
Hi-
It sounds like the problem is the trigger tag- if the group doesn’t run, none of the values will get updated, and you’ll always just see the initial “waiting” quality. It sounds like there must be something wrong with the trigger path that isn’t immediately apparent. What kind of tag is the trigger? Is it simply an OPC item in the group, or is it actually a SQLTag that you’ve referenced in the group? Is there, by chance, another tag with the same name in the group?
It might be easiest if you right click the group, export to XML (while you have it set up with the trigger), and then post it here or email it to support@inductiveautomation.com. Also, please note which version of Ignition you’re using.
Regards,
Hey Colby,
I wrote the previous message and started playing with the tags again. This time I lost connection with the server and I got a message saying DCOM settings issue. I had connectivity initially and also had real time values when not using trigger. So, I did not bother looking at DCOM settings.
Followed one of the threads that took me to white papers , did all the necessary changes and boom, works like a charm now !! 
Thanks a lot for your input. The trigger was just an OPC item.
Vishal
Great, glad you got it figured out.
Regards,