Equivalent WoT TD definition

Additional semantic annotations at property and action level

Description

A reference in OPC UA is used to define the relationship between two nodes. OPC UA defines several hierarchical and non-hierarchical references. In this specification version, a minimal set of references (e.g., HasComponent, HasTypeDefinition) can be used in a TD to represent the relationship between interaction affordances or between a Thing and its interaction affordances.

Some references are defined by own terms (e.g., uav:componentOf") or can be part of @types definitions.

Details about the reference types that are mapped within a TD are provided in Section 7.3.

Snippet example in OPC UA (e.g., as nodeset)

…<UAVariable DataType="Double" NodeId="ns=3;i=6125" BrowseName="3:ActualPosition">

<References>

<Reference ReferenceType="HasComponent" IsForward="false">ns=3;i=5001</Reference></Reference>

</UAVariable>…

Transformed usage in a TD definition (as snippet)

"properties": {

"3:ActualPosition": { "title": "Actual Position", "uav:componentOf": ["ns=3;i=5001"], …