A.4.2.2 Object Nodes

A node of Object Node class in the OPC UA server is represented in the Data Access COM UA Proxy as a Branch.

The root of the Data Access COM UA Proxy is the Objects folder of the OPC UA Server.

The OPC UA Address space hierarchy is discovered using the Browse Service for the Objects Node using the following filters:

• BrowseDirection as Forward

• ReferenceTypeId as Organizes and HasChild.

• IncludeSubtypes as True

• NodeClassMask as Object and Variable

The DisplayName of the OPC UA node is used as the Name for each Branch in the Data Access COM UA Proxy

Each Branch in the Data Access COM UA Proxy is assigned 3 properties:

• UA Browse Name (Property ID: 613): The value of the BrowseName attribute of the node in the OPC UA Server is assigned to this property.

• UA Description (Property ID: 614): The value of the Description attribute of the node in the OPC UA Server is assigned to this property, if a Description attribute is provided.

• Item Description (Property ID: 101): The value of the DisplayName attribute of the node in the OPC UA Server is assigned to this property.

NOTE COM DA Clients typically display the ItemID and the Item Description. Since the ItemID generated by the UA Proxy can be particularly difficult to read and understand, proxies can use the DisplayName as value for the Item Description Property as it will be easier to understand by a human user.