This structure contains elements that describe changes of the model. Its composition is defined in Table 156.

Table 156– ModelChangeStructureDataType Structure

Name

Type

Description

ModelChangeStructureDataType

structure

affected

NodeId

NodeIdof the Nodethat was changed. The client should assume that the affected Nodehas been created or deleted, had a Referenceadded or deleted, or the DataTypehas changed as described by the verb.

affectedType

NodeId

If the affected Nodewas an Objector Variable, affectedTypecontains the NodeIdof the TypeDefinitionNodeof the affected Node. Otherwise it is set to null.

verb

Byte

Describes the changes happening to the affected Node.

The verbis an 8-bit unsigned integer used as bit mask with the structure defined in the following table:

Field

Bit

Description

NodeAdded

0

Indicates the affected Nodehas been added.

NodeDeleted

1

Indicates the affected Nodehas been deleted.

ReferenceAdded

2

Indicates a Referencehas been added. The affected Nodemay be either a SourceNodeor TargetNode. Note that an added bidirectional Referenceis reflected by two changes.

ReferenceDeleted

3

Indicates a Referencehas been deleted. The affected Nodemay be either a SourceNodeor TargetNode. Note that a deleted bidirectional Referenceis reflected by two changes.

DataTypeChanged

4

This verb may be used only for affected Nodesthat are Variablesor VariableTypes. It indicates that the DataType Attributehas changed.

Reserved

5:7

Reserved for future use. Shall always be zero.

A verb may identify several changes on the affected Node at once. This feature should be used if event compression is used (see OPC 10000-3for details).

Note that all verbsshall always be considered in the context where the ModelChangeStructureDataType is used. A NodeDeleted may indicate that a Nodewas removed from a view but still exists in other Views.

Its representation in the AddressSpaceis defined in Table 157.

Table 157– ModelChangeStructureDataType Definition

Attributes

Value

BrowseName

ModelChangeStructureDataType