This EventType is defined in OPC 10000-3. Its representation in the AddressSpace is formally defined in Table 55.

Table 55 – SemanticChangeEventType definition

Attribute	Value
BrowseName	SemanticChangeEventType
IsAbstract	True
References	NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the BaseEventType defined in 6.4.2, which means it inherits the InstanceDeclarations of that Node.
HasProperty	Variable	Changes	SemanticChangeStructureDataType[]	PropertyType	Mandatory
Conformance Units
Base Info SemanticChange

This EventType inherits all Properties of the BaseEventType. Their semantic is defined in 6.4.2. The SourceNode Property for Events of this type shall be the Node of the View that gives the context of the changes. If the whole AddressSpace is the context, the SourceNode Property is set to the NodeId of the Server Object. The SourceName for Events of this type shall be the String part of the BrowseName of the View, for the whole AddressSpace it shall be "Server".

The additional Property defined for this EventType reflects the changes that issued the SemanticChangeEvent. Its structure is defined in 12.17.