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Uniqueness of NodeIds

Sascha Kattelmann

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09/02/2019 - 07:16

Hi!

From part, 5.2.2:

Nodes are unambiguously identified using a constructed identifier called the NodeId. Some Servers may accept alternative NodeIds in addition to the canonical NodeId represented in this Attribute.

My question is about this quote. NodeIds can have different types (integer, string, opaque, GUID). Is it possible to have two NodeIds of different type representing the very same Node? And what is the second sentence relating to? Aliases? Or the "opaque" NodeIds?

Randy Armstrong

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09/02/2019 - 08:08

The uniqueness of a NodeId is specified by { NamespaceIndex | IdType | Identifier }

Many NodeIds can point to a single Node;

Each NodeId can only reference a single Node;

When reading the NodeId Attribute the Server returns the 'canonical' or 'primary' NodeId. All other NodeIds are like aliases.

Sascha Kattelmann

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09/03/2019 - 01:54

Thank you 🙂 that was also our understanding from reading the specs but we wanted to clear up some potential misunderstandings.

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