Connecting with Ignition OPC UA server with third-party OPC UA client

Hello there,

I am currently struggling with connecting my C#/.NET application to the Ignition OPC UA server.
The setup of the server, PLC device is:

Using the Quick client i have tested the connection with a tag (see image above)

Now all I need is the “path” to the tag that needs to be set into my application. Currently what I can think of is the following: “opc.tcp://[Device1]PROGRAM:SFX0908_HMI_01.L_MACHINENR”

However the path above is not valid. What is,based upon the configuration of the server and plc device that i have posted above, the correct path to subscribe to an item in the Ignition OPC server?

The application is already working correctly with a Siemens OPC UA server (with a Siemens PLC), now I have to add the possibility to connect to a different OPC UA server that is connected to an AllenBradley PLC.

Anyone that can give me the correct path or something else that I am missing?
Thanks in advance,
Sorry for the long picture, i am only allowed to post one image apparenty…


OPC UA works with NodeIds, so whatever this path might be is specific to your software.

The NodeId in the Ignition OPC UA server looks like it it’s ns=1;[Device1]PROGRAM:SFX0908_HMI_01.L_MACHINENR in this case. Maybe you need to include the “ns=1” in your path.

Dear Kevin,

Thanks for your response!

ns=1;s=[Device1]PROGRAM:SFX0908_HMI_01.L_MACHINENR is what is currently used to create a new item to be monitored by the opc ua client. When this is created, an exception is triggered: creation of data monitored item failed…

There should be a StatusCode indicating the failure to go with that message…

NodeIds are case-sensitive as well… so you might try using the same case as in your screenshot.

1 Like

The StatusCode is 'BadNodeIdUnknown".

For the connection with the Siemens OPC ua server I only had to modify the node number to 6 and use the following path:
For the connection with KEPServer EX server I use node 2 and the path:

and both of those connections are running fine without any other modifications to the application.

I matched the case from the quick client and suddenly the first item to be monitored was no longer triggering the exception but the second item is. I will have to convert some more tags to be sure but for now it looks that the case-sensitivity is the key to my solution…

Thank you for your remark about the case-sensitivity!
When I have modified my tags I will post the result.

Problem is solved, it turnes out the case-sensitivity was the problem.

Kevin thank you