Adding OPC Tags

Module Development
21

How to read tag values for a group of tags?
The read method needs an array of nodeIDs, are all ID unique in the server in the entire browse space?
How to get the fully qualified tag path on the OPCUA server of Ignition?

Prafull

22

Does Ignition opcserver support the “TranslateBrowsePathsToNodeIds” service?
What is the correlation between tag paths and the exposed tag’s paths in opcua server?
Regards
PRAMANJ
http://www.pramanj.com

23

[quote=“Pramanj”]Does Ignition opcserver support the “TranslateBrowsePathsToNodeIds” service?
What is the correlation between tag paths and the exposed tag’s paths in opcua server?
Regards
PRAMANJ
http://www.pramanj.com[/quote]

Yes, TranslateBrowsePathsToNodeIds is supported, but doesn’t have anything to do with the Ignition tag path.

It looks like nodes that represent Ignition tags being exposed via the OPC-UA server just use the tag path as the NodeId.

24

Oh I see! It makes sense, as the Tag Path is unique. I thought node ID is a number, but its a string!
But the tag path on the OPC Browser shows value as “ns=2;s=[default]New Tag” as tag path. What is ns=2?
regards
Prafull
http://www.pramanj.com

25

namespace 2; in OPC-UA all nodes belong to a namespace. The NodeId has two components - namespace and identifier. “ns=2;s=…” is the syntax for describing a NodeId.

26

Ok thanks a lot for the explanation.
Best regards
Prafull
http://www.pramanj.com