EventAreas in the A&E COM Serverare represented in the A&E COM UA Wrapper as Objectswith a TypeDefinitionof BaseObjectType. The EventNotifier Attributefor these Objectsalways has the SubscribeToEvents flag set to True.

The root Area is represented by an Objectwith a BrowseNamethat depends on the UA Server. It is always the target of a HasNotifier Referencefrom the Server Node. The root Area allows multiple A&E COM Servers to be wrapped within a single UA Server.

The Area hierarchy is discovered with the BrowseOPCAreas and the GetQualifiedAreaName Methods. The Area name returned by BrowseOPCAreas is used as the BrowseNameand DisplayNamefor each Area Node. The QualifiedAreaName is used to construct the NodeId. The NamespaceURI qualifying the NodeIdand BrowseNameis a unique URI assigned to the combination of machine and COM Server.

Each Area is the target of HasNotifier Referencefrom its parent Area. It may be the source of one or more HasNotifier References to its child Areas. It may also be a source of a HasEventSource Referenceto any sources in the Area.

The A&E COM Servermay not support filtering by Areas. If this is the case then no Area Nodes are shown in the UA Serveraddress space. Some implementations could use the AREAS Attributeto provide filtering by Areas within the A&E COM UA Wrapper.