The OPC UA Meta Model (the OPC UA Address Space Model) is represented by UML classes and UML objects marked with the stereotype <<TypeExtension>>. Those stereotyped UML objects represent DataTypesor ReferenceTypes. The domain model can contain user-defined ReferenceTypes andDataTypes, also marked as <<TypeExtension>>. In addition, the domain model contains ObjectTypes, VariableTypes etc. represented as UML objects (see Figure B.1).

The OPC Foundation specifies not only the OPC UA Meta Model, but also defines some Nodesto organise the AddressSpaceand to provide information about the Serveras specified in OPC 10000-5.


Figure B.1– Background of OPC UA Meta Model