6.5.2.1 ReadEventDetails structure details

Table 29 defines the ReadEventDetails structure. This parameter is only valid for Objects that have the EventNotifier Attribute set to TRUE (see OPC 10000-3). At least two of the three parameters, numValuesPerNode, startTime, and endTime shall be specified.

Table 29 – ReadEventDetails Structure
NameTypeDescription
ReadEventDetailsStructureSpecifies the details used to perform an Event history read.

numValuesPerNode

CounterThe maximum number of Events returned for any Node over the time range. If only one time is specified, the time range shall extend to return this number of Events. The default value of 0 indicates that there is no maximum.

startTime

UtcTimeBeginning of period to read. The default value of DateTime.MinValue indicates that the startTime is unspecified.

endTime

UtcTimeEnd of period to read. The default value of DateTime.MinValue indicates that the endTime is unspecified.

Filter

EventFilterA filter used by the Server to determine which HistoricalEventNode should be included. This parameter shall be specified and at least one EventField is required. The EventFilter parameter type is an Extensible parameter type. It is defined and used in the same manner as defined for monitored data items which are specified in OPC 10000-4. This filter also specifies the EventFields that are to be returned as part of the request.

Its representation in the AddressSpace is defined in Table 30.

Table 30 – ReadEventDetails definition
Attribute Value
BrowseNameReadEventDetails
IsAbstractFalse
References NodeClass BrowseName DataType TypeDefinition Other
Subtype of the HistoryReadDetails defined in Table 28
Conformance Units
Historical Access Events