The ReferenceDescriptionVariableType is a subtype of the BaseDataVariableType. It is used as container to expose additional information of a Reference. The Value contains the description of the Reference the Variable represents.

The Reference as defined in the Value shall be exposed in the OPC UA Server containing the Variable. The IsForward field in the Value indicates the browsable direction of the Reference. It is not required that the opposite direction is browsable. The VariableType is formally defined in Table 14.

Table 14 – ReferenceDescriptionVariableType Definition

Attribute		Value
BrowseName		ReferenceDescriptionVariableType
IsAbstract		FALSE
ValueRank		−1 (−1 = Scalar)
DataType		ReferenceDescriptionDataType
References	NodeClass		BrowseName	DataType	TypeDefinition	Other
Subtype of the BaseDataVariableType defined in OPC 10000-5
HasProperty	Variable		ReferenceRefinement	ReferenceListEntryDataType[]	PropertyType	O
Conformance Units
Base Info ReferenceDescription

The optional Property ReferenceRefinement contains an array of References refining the original Reference represented by an instance of ReferenceDescriptionVariableType. Each entry in the array contains the ReferenceType, direction and TargetNode. The SourceNode of the first entry in the array is the SourceNode of the Value of the instance of ReferenceDescriptionVariableType. The SourceNode of all other entries is the TargetNode of the previous entry. The TargetNode of the last entry shall be the TargetNode of the instance of ReferenceDescriptionVariableType.