06/19/2020
Hello Everyone,
In my OPC UA implementation I use the nodeset file Opc.Ua.NodeSet2.xml as the source of truth for those nodes that are defined by OPC Foundation. The problem is that, according the nodeset file, the supertype of the NodeId DataType is not the Structure DataType but the BaseDataType. This is how it is defined in the file:
<UADataType NodeId=”i=17″ BrowseName=”NodeId”>
<DisplayName>NodeId</DisplayName>
<Documentation>https://reference.opcfoundatio…..on>
<References>
<Reference ReferenceType=”HasSubtype” IsForward=”false”>i=24</Reference>
</References>
</UADataType>
Here we have the claim that the NodeId DataType is subtype if the (i=24) BaseDataType. At the same time, the specification describes this type as a structured type (and in fact this is a structure with 3 fields).
Is it a real mistake? Or I misunderstand the declaration.
BTW, the same I see problem with ExpandedNodeId.
Thanks.
05/30/2017
Part 6 defines 24 “built-in types” which are fundamental types with custom encodings. NodeId and ExpandedNodeId are two of these types. It is called a lower case “structured type” because it set of name-value pairs but it is not an upper case “Structure”.
See https://reference.opcfoundatio…..rt6/5.1.2/
Note the text in Part 3:
https://reference.opcfoundatio…..rt3/8.2.1/
This Built-in DataType is composed of three elements that identify a Node within a Server.
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