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OPC Collector receives Bad when OPC Server shows Good

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I have an issue where the OPC Collector is showing No Data even though the OPC server shows Good data. The value in the Historian maintains, but the View will show Empty. The Value in the OPC server does not change frequently, so the value in the OPC server showing Good is the same value that is showing in the Historian as No Data. I am assuming because the value is not changing the Historian is not changing, but I would think the quality change should pick up. A quick solution is to stop and restart the OPC collector (and this does work), however this happens frequently enough that is something that would need to be monitored regularly. 

Is there a setting that can control that when the quality value changes, the Historian will log that?

 

Here you can see the Historian captured No Data, but maintained the value

 

Here you can see the View captured No Data, and Empty as the Value

 

Here you can see the OPC Server is showing the value as Good

 

There are other values within this group that maintain the Good reading, so it is not an issue with the Group.

Any ideas greatly appreciated

4 replies

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    • timothy_vertin
    • 9 mths ago
    • Reported - view

    Hey erice,

    I have the same thing going on with OPC data, particularly data that doesn't change very often, like machine status bits or setpoints.  From what I have discovered, the historian checks the timestamp from the source, and if the timestamp is duplicate, which it would be if it hadn't changed, then it will flag it as bad and Axiom will display it as "NoData."  Not an ideal fix but more of a band aid, you can go into the events/calcs and do what I call a "quality override" statement and create a new tag based on the same data.....

    There is a problem with this approach, if you're data is no good then it will display the last good value as if nothing was wrong.  For my purposes though, it's totally fine.  Good luck and hopefully this issue is addressed in the future.

    Regards,

    Tim

    • eric_wamsley
    • 13 days ago
    • Reported - view

    I'm having the same issue with a lot of tags, showing "No Data" for the same reasons.  Looking for any updates to this issue.

      • erice
      • 13 days ago
      • Reported - view

       The original issue for me was that the <opcua_publish_interval> (in the session opc config)was set to 0. When I set it to 1000 the issue went away. However, with the upgrade to V24, the issue has started again and now I'm being told it is an issue with threading and they don't know when they will have a fix for it. But this is really only a problem for data that doesn't change frequently. For data that changes frequently it is just a blip. If this is happening with you on data that changes frequently, then there is probably another issue. 

      • eric_wamsley
      • 13 days ago
      • Reported - view

       This is only happening for data that doesn't change frequently.  However, it's only happening from specific type of OPC DA server, all my other collectors are connected to Kepware OPC DA servers and this is not an issue.  I think it may be a configuration from the OPC DA server setup that the canary logger is connected to.    I have tags from kepware that haven't changed in a week and sill shows GOOD quality tag in canary with a value, but the ones from PCS7 DA server that have a time stamp over a week ago are showing NO DATA, even though is should be good with the value from a week ago.  It almost seems like the PCS7 OPC DA server is this issue and not sending data out until it changes?  Where Kepware is still sending data with the week old TVQ. 

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