Table 20 defines the ReadEventDetails structure. This parameter is only valid for Objects that have the EventNotifier Attribute set to TRUE (see OPC 10000-3). Two of the three parameters, numValuesPerNode, startTime, and endTime shall be specified.
|
Name |
Type |
Description |
|
ReadEventDetails |
Structure |
Specifies the details used to perform an Event history read. |
|
numValuesPerNode |
Counter |
The maximum number of values returned for any Node over the time range. If only one time is specified, the time range shall extend to return this number of values. The default value of 0 indicates that there is no maximum. |
|
startTime |
UtcTime |
Beginning of period to read. The default value of DateTime.MinValue indicates that the startTime is Unspecified. |
|
endTime |
UtcTime |
End of period to read. The default value of DateTime.MinValue indicates that the endTime is Unspecified. |
|
Filter |
EventFilter |
A 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. |