Beckhoff giving me a bad("unknown: unknown") for tags?

Using Ignition 8.1.3 connected to a Beckhoff PLC. The connection itself seems fine -

and I can browse the PLC

but every tag, whether its a UDT instance or a plain old integer tag all give me the same error

I found another post that said this may be a licensing issue with Beckhoff but according to my coworker who is doing all the PLC work it is now fully licensed and we have restarted it.

Has anyone run into this issue with a Beckhoff before? I am trying to figure out if I am better off calling Ignition tech support or Beckhoff tech support regarding this issue.

Beckhoff model cx9020-0115

Do you have a external OPC package? Like Kepware? That you can see if you’re able to connect and get Good quality or not?

Perhaps a Wireshark capture would be good?

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Good thinking. Will try and report back.

This was my first inclination. It’s a licensing or other StatusCode from a newer version of the OPC UA spec than we’re using right now.

Use Wireshark, or turn the OpcUaSubscriptionModel and OpcUaSubscriptionSynchronizer loggers to TRACE and see if/why MonitoredItem creation is failing.

I didn’t see any logs from those that said anything bad about a MonitoredItem creation failing, but Kepware is also saying all the tags are bad so definitely think its something strictly to do with Beckhoff at this point. Thanks for the help

You’d have to set them to TRACE and then delete/create the tag or edit/save the connection.

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Ah ok, I did set them to trace and restarted the gateway, I didn’t make another tag or edit the connection.

However given that Kepware is also telling us Bad Quality for the tags from Beckhoff I am assuming that it has nothing to do with Ignition at this point. But good to know for future debugging.

Log level changes made in the gateway UI don’t persist across restarts.

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Oh I thought they did. Another tidbit to keep in mind. Thanks

Is the Beckhoff PLC in run mode with PLC project running? Or config mode? If I recall correctly, something like what you’re seeing is expected if PLC is not running. EDIT: I just tested and confirmed you will get bad quality when PLC is in config mode. Stopping PLC while in run mode did not immediately cause bad quality, so I’m not sure it’s necessary for PLC code to be running, though you’ll definitely get bad quality if PLC is not in run mode as indicated by green (vs. blue) button active on TwinCAT. toolbar

Tag quality should be fine even with resettable TwinCAT OPC UA trial license. We use that routinely for commissioning, buying and applying license before trial expires after commissioning.

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Thanks for the tip. My coworker put it into the run mode via green button and unfortunately all tags coming through to Ignition are still bad("unknown: unknown"). If you have any other idea’s please let me know but I think otherwise it’s probably time to get in touch with Beckhoff support.

Beckhoff support ought to be helpful and it’s free. Some other things you could try:

  • Activate current configuration, restart PLC in run mode (green button noted in previous post), go online, and start PLC (if not already set to auto-start–verify code is running).
  • Check status and settings in TwinCAT OPC UA configurator–might find a clue here. Try reactivating OPC UA configuration and restarting TwinCAT OPC UA server.
  • Try connecting with Beckhoff’s sample client, though I think your test with Kepware already covered this base.

@bkarabinchak.psi, I’m curious what the resolution to this was.

I don’t think this was your issue, but since my post above I was helping out a coworker where they had everything else right, but hadn’t restarted the TwinCAT OPC UA server after applying a license to it. This also results in bad quality. In TwinCAT 3.1 running relatively current versions of TwinCAT OPC UA, you can see the license status by double-clicking first node under TwinCAT connectivity project while online with TwinCAT OPC UA server in Visual Studio:

In TwinCAT 2 (and older OPC UA version of TwinCAT 3.1, I think), you would find this in the TwinCAT OPC UA Configurator program.

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My coworker was under the impression that we were no longer on a 7 day trial license and that we were fully licensed. It turned out that was not the case and it was a simple case of the 7 day trial expiring and needing to be reset.

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