Error writing to OPC UA tag : "Bad"

Ignition
1

I'm working on duplicating an existing tool that writes to OPC tags to control access level on some PLCs. I have setup the tags in the same manner when I expanding the tool previously. The tool does nothing when the field is edited. If I step back and try to change the value of a tag in the tag browser, I get this error:

Error writing to User Access Level.value: Bad
ErrorWriting

I have opened the PLC program and validated that the corresponding UDT for the Controller tags has External Access set to Read/Write.

ExternalAccess
ExternalAccess409×551 15.9 KB

If I edit the tag in the PLC, the corresponding value updates in Ignition.

The tag is a Controller tag in scope and in the UDT is setup as a DINT, just like the other tags that are set up in the existing tool (different equipment but same Allen Bradley Contrologix hardware)

UDT_Tag
UDT_Tag1056×34 2.25 KB

I have tried changing the tag permissions to Public and I still receive the same message

I tried to look at the gateway logs put couldn't find any additional details about the error. Not sure if there are individual errors logged for OPC transactions.

Where can I find more info about this error?

Any advice is appreciated.

2

You might mention what device driver you're using and show the configuration. Someone may spot an error there.

You've tagged the question as Perspective but I don't think that's relevant to the problem you're describing.

3

These devices are using the Allen-Bradley Logix Driver.

OPC Drivers
OPC Drivers731×126 4.33 KB

Here is a sample configuration. It's essentially the same (except name/IP address) as the OPC devices whose tags CAN be edited.

OPC Driver Settings
OPC Driver Settings1039×802 25.2 KB

4

Did you disable "automatic rebrowse" in the connection's advanced properties? Have you tried an edit/save cycle on the device to restart it?

{ There are reports that some later Logix firmware versions don't always flag tag edits for 3rd party connections as documented by Rockwell. Restarting a device should force a rebrowse anyways. }

5

Studio5000 Firmware is 30.14

I just tried editing the connection properties on all of the devices. I disabled automatic rebrowse and then disabled->enabled the OPC-UA device connection.

The same error still displays if I try to edit the tag in tag browser.

Is there a place I can find a more meaningful error log to perhaps troubleshoot more?

6

I found this thread that sounds like probably the same problem. They mention turning on Trace-level of logging for com.inductiveautomation.ignition.gateway.opcua.client.connection.OpcUaConnection but I'm not sure where to find that. I've browsed around a bit in the Server setup webpages but I don't see where I can specify or view logs for specific parts of Ignition. I'll keep looking.

7

Consider restarting the entire OPC UA Module, if you can tolerate the disruption. I've encountered situations where OPC Node properties get "stuck".

8

We are luckily not in production today, so I was able to try that. Seemingly no change, unfortunately.

9

Are you sure that member of that datatype is writable? Datatypes and AOI types have per-member external access controls.

10

That was it, @pturmel. The Parameter inside the AOI that corresponded to this tag was set to Read Only. I tried a bit of foolery but it seems that the only way to change the External Access level on such a parameter is Offline, so that means the settings change requires a Download, in case anyone runs into this in the future.

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