B.3 Meta Model
B.3.1 Base
Base is shown in Figure B.4.

B.3.2 ReferenceType
ReferenceType is shown in Figure B.5 and predefined ReferenceTypes in Figure B.6.

If Symmetric is “false” an InverseName shall be provided.

B.3.3 Attributes
Attributes are shown in Figure B.7.

There may be more Attributes defined in other parts of this series of standards.
Attributes used for references, which have a NodeId as DataType, are not shown in this diagram but are shown as stereotyped associations in the other diagrams.
B.3.4 Object and ObjectType
Objects and ObjectTypes are shown in Figure B.8.
B.3.5 EventNotifier
EventNotifier are shown in Figure B.9.

B.3.6 Variable and VariableType
Variable and VariableType are shown in Figure B.10.

The DataType of a Variable shall be the same as or a subtype of the DataType of its VariableType (referred with HasTypeDefinition).
If a HasProperty points to a Variable from a Base “A” then the following constraints apply:
The Variable shall not be the SourceNode of a HasProperty or any other HierarchicalReferences Reference.
All Variables having “A” as the SourceNode of a HasProperty Reference shall have a unique BrowseName in the context of “A”.
B.3.7 Method
Method is shown in Figure B.11.

B.3.8 DataType
DataType is shown in Figure B.12.
B.3.9 View
View is shown in Figure B.13.
