Tags stay bad after Ignition reconnects to local third party OPC-UA server

I’m using some kind of proprietary OPC tunneling software provided by the manufacturer to talk to several of their machines. The software connects to each machine’s OPC-DA server remotely and then creates a local OPC-UA server on the same server as Ignition for each, which Ignition (v8.0.15) is then connected to.

The connections work fine until something causes them to fault, usually because a machine is turned off. However, once the connection is re-established, the status changes back to “Connected” on the OPC Connections page of the Ignition gateway but the tags stay on bad quality with unknown values. I’m also able to browse the tags in the OPC-UA software itself and via a separate OPC client installed on the same server, which leads me to think that the problem is with Ignition.

I’m sometimes able to get it working again by disabling the OPC connection in the gateway and then re-enabling it, but not always.

Any ideas on how to fix this?


If you can invoke the fault at will, try setting the log levels for the loggers found by searching OpcUaSubscriptionModel and OpcUaSubscriptionSynchronizer to TRACE and then cause it to fault and reconnect. After it’s had some time to try and re-create subscriptions after reconnecting grab the logs and upload them here.


Or, if you can set the connections up without security and get a Wireshark capture during all of this, that would be even better.

Ignition_OPC_Log.zip (2.1 MB)

Attached are the logs for when I attempted to refresh the connection to two of the lines by clicking “edit” next to the OPC connections in the gateway and then clicking “save changes” without actually changing anything. Before I did this, the status of all of the OPC server connections was “connected” but all of the tags were bad quality.

Line 3 reconnected successfully after I refreshed the connection but line 4 failed (the logs for that start at 10:22:42). I had to refresh the connection to the line 4 OPC server several times before the tags subscribed successfully.

The only really odd thing I see is that it looks like you have 2 tags being resubscribed (Error_Code and State) and their initial value comes from the server as null/None, which causes the logic in your tag change scripts to error out.

Nothing else looks odd re: OPC UA but maybe there’s more to it.

I’m still on vacation and will be off the grid for most of the week. I recommend you call support and work with them.

Okay, thanks for your help.

After talking to support, I changed the tags to a polled scan class and that seems to have fixed the issue.

That’s an unfortunate workaround, not a fix. Thanks for updating anyway I guess.

That’s true but support were unable to identify the root cause so that’s the closest to a fix I could get.