Hello.
I am currently working with several PLCs on a project.
I would like to know if it is possible to modify the „Nodeid“ of the variables that are read or written by OPC. I am more specific?
I have a variable called Ana00001, this variable has a „Nodeid=ns=6;s=Arp.Plc.Eclr/MQTT1.Ana00001“.
I would like to know if it is possible to modify the value „ns=6“ and if it is possible how to do it.
Best regards and thanks
pc1-single-point-datasheet-en.pdf
db_en_axl_f_sgi2_1h_107958_en_02.pdf
AXL_SGI_3.pdf
Hello.
The short answer is no (sorry).
Do you mind me asking why you want to do this?
According to the relevant part of the OPC UA specification, which is discussed here:
High Performance OPC UA Server SDK: OPC UA NodeId Concepts In the old days the classic DA Server have used simple “string”-Identifiers. The so called “ItemID” was a fully qualified name that was unique throughout the whole server (there was only one “namespace”). Furthermore, the classic DA Servers had only capabilities for a simple hierarchy, i.e. a tree-like structure with branches and leaves. … in the „Client Namespace Mapping“ section (at the end of the page) it describes how OPC UA Clients should not rely on the namespace index to remain the same. Instead, a client should resolve the namespace index each time it connects to the server, using the (always unchanging) namespace URI. This means that the value of the namespace index should not matter to OPC UA Clients. If you have an OPC UA client that does not use the namespace URI to resolve the namespace index, then I’m afraid this is a question for the client vendor.
Hello.
It is just what you say, it is relying on the namespace index to remain the same. So I will use the namespace URI (always invariant), as you suggest.
Thanks