We have similar problems with the Thingworx OPC UA Client. For some reason this client constantly reconnects to the KEPServer. In the KEPServer EX Runtime I can see the number of connected clients increase every couple of seconds. I have a feeling that this is not the normal behaviour so maybe this is what causes the problem with reading the Tag values.
@Alberto: Did you try changing the baseType to INTEGER? In ThingWorx the NUMBER baseType is used for floating point numbers. Based on the name "Counter" I guess this Tag1 is an integer type.
Hi Alberto, I finally figured out why I could not read the Tag values, maybe the problem is the same for you too.
The main problem was that the namespaceIndex was not correct, I used the following configuration for the opcua_subscription:
"dataItems" : [
"name" : "Counter1",
"baseType" : "INTEGER",
"identifier" : "Channel1.Device1.Tag1",
"namespaceIndex" : 2,
"isReadOnly" : false
The identifier needs to be the complete path of the tag for example: "Channel1.Device1.Tag1" and the namespace index in my case was 2 (it is probably the same for you as well)
You can check for the correct namespaceIndex using the UAExpert tool. It can be downloaded from the following link: OPC UA Clients - Unified Automation
I hope this will be helpful.