.NET Based OPC UA Client/Server SDK  2.6.1.422
UnifiedAutomation.UaBase.ReadEventDetails Class Reference

Selects a set of events from the history database by specifying a filter and a time domain for one or more objects or views. More...

Inherits UnifiedAutomation.UaBase.HistoryReadDetails.

Public Member Functions

 ReadEventDetails ()
 The default constructor. More...
 
override void Encode (IEncoder encoder)
 
override void Decode (IDecoder decoder)
 
override bool IsEqual (IEncodeable encodeable)
 Checks if encodeable is the same object or has the same content More...
 
override object Clone ()
 
- Public Member Functions inherited from UnifiedAutomation.UaBase.HistoryReadDetails
 HistoryReadDetails ()
 The default constructor. More...
 

Properties

uint NumValuesPerNode [get, set]
 The maximum number of values returned for any node over the time range. More...
 
DateTime StartTime [get, set]
 The beginning of the period to read. More...
 
DateTime EndTime [get, set]
 The end of the period to read. More...
 
EventFilter Filter [get, set]
 A filter used by the Server to determine which HistoricalEventNode should be included. More...
 
override ExpandedNodeId TypeId [get]
 
override ExpandedNodeId BinaryEncodingId [get]
 
override ExpandedNodeId XmlEncodingId [get]
 
- Properties inherited from UnifiedAutomation.UaBase.HistoryReadDetails
virtual ExpandedNodeId TypeId [get]
 
virtual ExpandedNodeId BinaryEncodingId [get]
 
virtual ExpandedNodeId XmlEncodingId [get]
 
- Properties inherited from UnifiedAutomation.UaBase.IEncodeable
ExpandedNodeId TypeId [get]
 Returns the UA type identifier for the encodable type. More...
 
ExpandedNodeId BinaryEncodingId [get]
 Returns the UA type identifier for the default binary encoding for the type. More...
 
ExpandedNodeId XmlEncodingId [get]
 Returns the UA type identifier for the default XML encoding for the type. More...
 

Detailed Description

Selects a set of events from the history database by specifying a filter and a time domain for one or more objects or views.

The ReadEventDetails structure is used to read the events from the history database for the specified time domain for one or more HistoricalEventNodes. The events are filtered based on the filter structure provided. This filter includes the event fields that are to be returned.

The startTime and endTime are used to filter on the Time field for events.

The time domain of the request is defined by startTime, endTime, and numValuesPerNode; at least two of these must be specified. If endTime is less than startTime, or endTime and numValuesPerNode alone are specified, the data will be returned in reverse order with later/newer data provided first, as if time was flowing backward. If all three are specified, the call shall return up to numValuesPerNode results, going from startTime to endTime, in either ascending or descending order, depending on the relative values of startTime and endTime. If numValuesPerNode is 0, all of the values in the range are returned. The default value is used to indicate that startTime, endTime, or numValuesPerNode is not specified.

It is specifically allowed for the startTime and the endTime to be identical. This allows the Client to request the event at a single instance in time. If startTime and endTime are identical, time is presumed to be flowing forward. If no data exists at the time specified, the server must return the Good_NoData StatusCode.

If a startTime, endTime, and numValuesPerNode are all provided, and if more than numValuesPerNode events exist within that time range for a given node, then only numValuesPerNode events per node are returned along with a continuationPoint. When a continuationPoint is returned, a Client wanting the next numValuesPerNode values should call HistoryRead again with the continuationPoint.

For an interval in which no data exists, the corresponding StatusCode shall be Good_NoData.

The filter parameter is used to determine which historical events and their corresponding fields are returned. It is possible that the fields of an EventType are available for real time updating, but not available from the historian. In this case, a StatusCode value will be returned for any event field that cannot be returned. The value of the StatusCode must be Bad_NoData.

If the requested timestamp format is not supported for a node, the operation shall return the Bad_TimestampNotSupported StatusCode. When reading events, this only applies to Event fields that are of type DataValue.

Constructor & Destructor Documentation

UnifiedAutomation.UaBase.ReadEventDetails.ReadEventDetails ( )
inline

The default constructor.

Member Function Documentation

override bool UnifiedAutomation.UaBase.ReadEventDetails.IsEqual ( IEncodeable  encodeable)
inlinevirtual

Checks if encodeable is the same object or has the same content

Parameters
encodeable
Returns

Reimplemented from UnifiedAutomation.UaBase.HistoryReadDetails.

Property Documentation

DateTime UnifiedAutomation.UaBase.ReadEventDetails.EndTime
getset

The end of the period to read.

The default value of DateTime.MinValue indicates that the endTime is Unspecified.

EventFilter UnifiedAutomation.UaBase.ReadEventDetails.Filter
getset

A filter used by the Server to determine which HistoricalEventNode should be included.

This parameter must 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. This filter also specifies the EventFields that are to be returned as part of the request.

uint UnifiedAutomation.UaBase.ReadEventDetails.NumValuesPerNode
getset

The maximum number of values returned for any node over the time range.

If only one time is specified, the time range must extend to return this number of values. The default value of 0 indicates that there is no maximum.

DateTime UnifiedAutomation.UaBase.ReadEventDetails.StartTime
getset

The beginning of the period to read.

The default value of DateTime.MinValue indicates that the startTime is Unspecified.


The documentation for this class was generated from the following file: