"system.opc.readValue" returns bad quality

Ignition
1

I am using Ignitions OPC UA server (Ignition OPC UA Server), I have configured an Omron FINS/TCP connection with a PLC. I can read the tags from the OPC Quick Client and from the Tag Browser, but when I try to read the tags using “system.opc.readValue” it returns a None value and a bad quality: Bad(“Bad_NodeIdUnknown: The node id refers to a node that does not exist in the server address space.”).
Thanks for any answer.

2

I’m thinking there’s an issue with the path you’re passing to the function. Can you show us the full call ?

3

Thank you Transistor

server = "Ignition OPC UA Server"
path = "[default]_Prueba señal Omron FINS/TCP__Ciclo Pulidora exteriores D5505"
qualifiedValue = system.opc.readValue(server, path)
print "Value: " + str(qualifiedValue.getValue())
print "Quality: " + qualifiedValue.getQuality().toString()
print "Timestamp: " + qualifiedValue.getTimestamp().toString()
4

Tip: use the </> code formatting button when posting code. It doesn’t matter in this instance but it does preserve code indentation and apply syntax highlighting. It’s essential for Python and makes any code much easier to read. There’s an edit button (pencil icon) below your post so you can fix it.

5

I see a non-ASCII character in path. Use the u'something' syntax for string constants with unicode characters.

6

If I understand you correctly, you mean something like this

server = "Ignition OPC UA Server"
path = u'[default]_Prueba señal Omron FINS/TCP__Ciclo Pulidora exteriores D5505'
qualifiedValue = system.opc.readValue(server, path)
print "Value: " + str(qualifiedValue.getValue())
print "Quality: " + qualifiedValue.getQuality().toString()
print "Timestamp: " + qualifiedValue.getTimestamp().toString()

But i have the same results.

7

Wait. What is [default] ? That looks like a tag path, not an OPC Item Path. You need to use the OPC Item Path.

Or perhaps you meant to use a system.tag.read*() function ?

8

I have tried using an OPC Item Path with the function system.opc.readValue and also using the tag path with the function system.tag.read*(), and both have worked.
Thank you pturmel.