Ignition OPC-UA client connecting to Softing SIS views it as recursive address space

@Kevin.Herron Using the OPC-UA beta module (8.0.16-SNAPSHOT (b2020072505)) running on Ignition 8.0.15 (b2020072213).

When I connect to the Softing SIS server version, which is connecting to a demo OPC-UA source, the address space is recursive as shown below, where I’m not able to get to the actual data.

When viewed in UAExpert:

Appears to be a bug with Ignition given that UAExpert is able to browse the address space correctly.

Let me know what I can test to troubleshoot.


A Wireshark capture while you browse from Ignition would probably help. Make sure you right-click > refreshed on the root node in the OPC Browser when you start capturing.

Thanks Kevin.

Attached are two captures in the ZIP: (1) Ignition browsing the space (through Designer) and (2) UAExpert browsing the space.

Let me know if these have the data you need.

Softing Captures.zip (8.8 KB)

I would be interested in knowing if this happens with the regular OPC UA module as well… not sure if that’s something you can test easily. If you do, make sure you set aside the current build you’re using because I don’t have it any more.

Ah, and also turning the logger(s) found when searching “OpcUaConnection” to TRACE might help as well.

Nevermind, I think I found the problem. It has something to do with the namespace URIs containing an “=” character.

Thanks. Based on what you know, is “=” a legal character for OPC URIs?

If so, let me know when you have a new module and I can test out.

It’s legal, there’s a bug in the parsing logic in the OPC UA stack we use.

Unfortunately since it has to be fixed in the stack and then subsequently that new version needs to be integrated into the Ignition OPC UA module this means I probably won’t be able to get a fix into the 8.0.x branch. More likely it will be fixed for 8.1.1 or 8.1.2.