This is a subtype of AuditHistoryUpdateEventType and is used for categorization of history value update related Events. This type follows all the behaviour of its parent type. Its representation in the AddressSpace is formally defined in Table 17.

Table 17 – AuditHistoryValueUpdateEventType definition

Attribute

Value

BrowseName

AuditHistoryValueUpdateEventType

IsAbstract

False

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the AuditHistoryUpdateEventType defined in OPC 10000-3, i.e. it has HasProperty References to the same Nodes.

HasProperty

Variable

UpdatedNode

NodeId

PropertyType

Mandatory

HasProperty

Variable

PerformInsertReplace

PerformUpdateType

PropertyType

Mandatory

HasProperty

Variable

NewValues

DataValue[]

PropertyType

Mandatory

HasProperty

Variable

OldValues

DataValue[]

PropertyType

Mandatory

ConformanceUnits

Historical Access Data Audit Events

This EventType inherits all Properties of the AuditHistoryUpdateEventType. Their semantic is defined in OPC 10000-3.

The UpdatedNode identifies the Attribute that was written on the SourceNode.

The PerformInsertReplace enumeration reflects the parameter on the Service call.

The NewValues identify the value that was written to the Event.

The OldValues identify the value that the Event contained before the write. It is acceptable for a Server that does not have this information to report a null value. In the case of an insert it is expected to be a null value.

Both the NewValues and the OldValues will contain a value in the DataType and encoding used for writing the value.