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I am novice to OPC Unified Architecture world and I'm studying it from basics. What exactly are namespaces and why it is always appended with NodeID?

mpm
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Tushar Mane
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  • YOu can consider namespace as a distinguisher Nodes from Different Sources, As a server can have nodes from multiple sources so namespaces are one which exposes which node belongs, under which tree. – Naushad Warsi Dec 10 '19 at 10:51

1 Answers1

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A namespace in OPC UA is like a container for node ids. There is the predefined namespace with index 0 from the OPC foundation. And there are many more namespaces, e.g. DI, PLCopen. Each namespace belongs to a specific OPC UA specification, and every OPC UA specification can define its own node ids. To make sure a specific ID uniquely identifies a specific node within a namespace you need to indicate the namespace ID.

More information can be found in the official OPC UA specification:

https://reference.opcfoundation.org/v104/Core/docs/Part3/8.2.2/

Stefan Profanter
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  • Thank you so much. Can you please guide me regarding how can I learn and master opc ua step by step? – Tushar Mane Oct 26 '17 at 15:07
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    There are a few Books available. A good one for beginners is "OPC UA - Unified Architecture: The Everyman's Guide to the Most Important Information Technology in Industrial Automation" – Stefan Profanter Oct 26 '17 at 19:03