OPC UA tag data doesn't flow unless I subscribe to it with an additional client

This is strange to me. I have a test opc ua server setup using this http://node-opcua.github.io/

I setup a Machine Data Source

I setup a Test Machine

But no tag data is flowing.

The instant I subscribe to it using the CommServer OPC UA Viewer the data starts flowing.


This is definitely interesting. I would suspect there’s something going on with the implementation here. To verify, we should check with an openly available client. There are a list of publicly available clients to test this with here: https://github.com/node-opcua/node-opcua/wiki/publicly-available-OPC-UA-Servers-and-Clients
Let me know if one of these works as expected, and we can go from there.


I ended up testing it with the Prosys OPC UA Simulation Server, and it worked as expected. I did notice that tulip is using the NodeOPCUA-Client which should just work beautifully with the node-opcua server… very strange.