Table 33 defines the ReadRawModifiedDetails structure. Two of the three parameters, numValuesPerNode, startTime, and endTime shall be specified.

Table 33 – ReadRawModifiedDetails structure

Name	Type	Description
ReadRawModifiedDetails	Structure	Specifies the details used to perform a “raw” or “modified” history read.
isReadModified	Boolean	TRUE for Read Modified functionality, FALSE for Read Raw functionality. Default value is FALSE.
startTime	UtcTime	Beginning of period to read. Set to default value of DateTime.MinValue if no specific start time is specified.
endTime	UtcTime	End of period to read. Set to default value of DateTime.MinValue if no specific end time is specified.
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 0 indicates that there is no maximum.
returnBounds	Boolean	A Boolean parameter with the following values: TRUEBounding Values should be returned FALSEAll other cases

Its representation in the AddressSpace is defined in Table 30.

Table 34 – ReadRawModifiedDetails definition

Attribute		Value
BrowseName		ReadRawModifiedDetails
IsAbstract		False
References	NodeClass		BrowseName	DataType	TypeDefinition	Other
Subtype of the HistoryReadDetails defined in Table 28
Conformance Units
Historical Access Read Raw
Historical Access Modified Values

When this structure is used for reading Raw Values (isReadModified is set to FALSE), it reads the values, qualities, and timestamps from the history database for the specified time domain for one or more HistoricalDataNodes. This parameter is intended for use by a Client that wants the actual data saved within the historian. The actual data may be compressed or may be all RawData collected for the item depending on the historian and the storage rules invoked when the item values were saved. When returnBounds is TRUE, the Bounding Values for the time domain are returned. The optional Bounding Values are provided to allow the Client to interpolate values for the start and end times when trending the actual data on a display.

The time domain of the request is defined by startTime, endTime, and numValuesPerNode; at least two of these shall be specified. If endTime is less than startTime, or endTime and numValuesPerNode alone are specified then the data will be returned in reverse order, with later data coming first as if time were flowing backward. If numValuesPerNode is not specified (set to 0), then all the values in the range are returned. A default value of DateTime.MinValue (see Table 33) is used to indicate when startTime or endTime is not specified. When only startTime (or only endTime) and numValuePerNode is specified, the provided time is used as a starting point and the requested number of values is returned.

The standard ContinuationPoint rules (see 6.3) apply. In addition, the following ContinuationPoint rule applies to ReadRawModifiedDetails If a startTime, endTime and numValuesPerNode are all provided and if more than numValuesPerNode values exist within that time range for a given Node then only numValuesPerNode values per Node shall be returned along with a ContinuationPoint.

It is specifically allowed for the startTime and the endTime to be identical. This allows the Client to request just one value. When the startTime and endTime are identical then time is presumed to be flowing forward. It is specifically not allowed for the Server to return a Bad_InvalidArgument StatusCode if the requested time domain is outside of the Server's range. Such a case shall be treated as an interval in which no data exists.

If Bounding Values are requested and a non-zero numValuesPerNode was specified then any Bounding Values returned are included in the numValuesPerNode count. If numValuesPerNode is 1 then only the start bound is returned (the end bound if the reverse order is needed). If numValuesPerNode is 2 then the start bound and the first data point are returned (the end bound if reverse order is needed). When Bounding Values are requested and no bounding value is found then the corresponding StatusCode entry will be set to Bad_BoundNotFound, a timestamp equal to the start or end time as appropriate, and a value of null. How far back or forward to look in history for Bounding Values is Server dependent.

For an interval in which no data exists, if Bounding Values are not requested, then the corresponding StatusCode shall be Good_NoData. If Bounding Values are requested and one or both exist, then the result code returned is Success and the bounding value(s) are returned.

For cases where there are multiple values for a given timestamp, all but the most recent are considered to be ModifiedValues and the Server shall return the most recent value. If the Server returns a value which hides other values at a timestamp then it shall set the ExtraData bit in the StatusCode associated with that value. The additional values can be retrieved with the isReadModified flag set to true, see 6.5.3.3. If the Server contains additional information regarding a value, such as Annotations, then the ExtraData bit shall also be set.

If the requested TimestampsToReturn is not supported for a Node, the operation shall return the Bad_TimestampNotSupported StatusCode.

When this structure is used for reading Modified Values (isReadModified is set to TRUE), it reads the ModifiedValues, StatusCodes, timestamps, modification type, the user identifier, and the timestamp of the modification from the history database for the specified time domain for one or more HistoricalDataNodes. If there are multiple replaced values the Server shall return all of them. The updateType specifies what value is returned in the modification record. If the updateType is INSERT the value is the new value that was inserted. If the updateType is anything else the value is the old value that was changed. See 6.9 HistoryUpdateDetails parameter for details on what updateTypes are available.

The purpose of this function is to read values from history that have been Modified. The returnBounds parameter shall be set to FALSE for this case, otherwise the Server returns a Bad_InvalidArgument StatusCode.

The domain of the request is defined by startTime, endTime, and numValuesPerNode; at least two of these shall be specified. If endTime is less than startTime, or endTime and numValuesPerNode alone are specified, then the data shall be returned in reverse order with the later data coming first. If all three are specified then 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 then all of the values in the range are returned. If the Server cannot return all ModifiedValues for a given timestamp in a single response then it shall return ModifiedValues with the same timestamp in subsequent calls.

The standard ContinuationPoint rules (see 6.3) apply. In addition, the following ContinuationPoint rule applies to ReadRawModifiedDetails. If more than numValuesPerNode values exist within that time range for a given Node then only numValuesPerNode values per Node are returned along with a ContinuationPoint.

If a value has been modified multiple times then all values for the time are returned. This means that a timestamp can appear in the array more than once. The order of the returned values with the same timestamp should be from the most recent to oldest modification timestamp, if startTime is less than or equal to endTime. If endTime is less than startTime, then the order of the returned values will be from the oldest modification timestamp to the most recent. It is Server dependent whether multiple modifications are kept or only the most recent.

If the requested TimestampsToReturn is not supported for a Node then the operation shall return the Bad_TimestampNotSupported StatusCode.