Tag stopped updating quality still showed good

I am using Ignition 8.1.1.
I had all the tags from one device stop updating. The data quality still showed it was good, even though it was not updating. The time stamp was 2 days old when it was brought to my attention. We also have an installation of Ignition 7.9.16 and it behaved the same.
I ran UAExpert on my PC and using VPN hardware was able to access the Beckhoff PLC the OPC server was running on. This used a separate Ethernet port. I was able to get a connection to the OPC server and I was able to get tags that were current. This shows me that something on the OPC server was alive and communicating.

How is the data quality determined? We had tags that had a timestamp that was 2 days old, but the quality still showed good. Understanding why the quality did not update might point us in a direction to resolve this.

Do you have logs you can upload? Is it still “stale” or did you reset the connection already?

The only circumstance in which Ignition will set the value or quality of an OPC tag by itself is when the connection is interrupted. Other than that it relies on the OPC UA subscription mechanism and only changes in value or quality are reported.

If an OPC tag has a value with good quality and a 2 day old timestamp then ostensibly the OPC UA server you are connected has not sent an update for 2 days.

edit: I should clarify, I mean the server has not reported a change in value or quality for 2 days. It is not expected to report changes in timestamp only.

I do not have logs from the OPC Server. The last logs from the OPC server are from 1/31/21. Which is my second mystery.

This is what I saw on ignition.
Ignition capture

UAExpert showed me this for a tag at roughly the same time. If I hit refresh the data changed.

The UAExpert logs did not show any issues.

One additional question about the quality, there has to be more to quality than just the OPC server sending data. If I loose the connection to the OPC server my quality changes. So, the server did not send an update when it was disconnected, yet the quality changed.

Could the OPC server and Ignition get out of sync? So it still thinks there is a connection which passes that part of the quality check but still off enough to not register the change in the tag.

Yes, this is the one circumstance I explained that Ignition will set the quality itself.

It seems they have somehow, but figuring out how or why may be difficult.

You should be able to get a log export from your Ignition gateway that may contain clues if we’re lucky.

Again - is this out occurring right now or have you already corrected it? If it’s occurring now we can try to view the server diagnostics using UaExpert, track down the Session entry from Ignition’s client, see which subscriptions exist and which one has the monitored item you highlighted, then see if there is still traffic between Ignition and the server for those subscriptions.

edit: and FWIW, you are not looking at the same tag in UaExpert as you are in Ignition, at least in your screenshots.

I’ve seen issues like this with OPCDA servers. You can try to disable and then re-enable the opc service, or ‘restart’ the tag. Sometimes it needs a kick in the you know what. Not ideal. But, frozen tags, they can happen, and ignition doesn’t try and warn you about it! if its a critical tag its good to throw the timestamp up there and even an alarm on the time stamp

Hello, Do you have solved the problem?

No, This issue still occurs.

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