Public Overloads Function ReadAnnotations( _
   ByVal startTime As OPCHDA.NET.OPCHDAtime, _
   ByVal endTime As OPCHDA.NET.OPCHDAtime, _
   ByVal server() As Integer, _
   ByRef annotationValues As OPCHDA.NET.OPCHDAannotation(), _
   ByRef errors As Integer() _
) As Integer

public int ReadAnnotations( 
   OPCHDA.NET.OPCHDAtime startTime,
   OPCHDA.NET.OPCHDAtime endTime,
   int[] server,
   out OPCHDA.NET.OPCHDAannotation[] annotationValues,
   out int[] errors
)

Parameters

startTime

The beginning of the history period to be read.

endTime

The end of the history period to be read.

server

The list of server item handles for the annotation items to be read.

annotationValues

OUT: Array of structures in which the annotation values are returned. The order of the structures in the array shall be the same as the order of server item handles.

errors

OUT: Array of HRESULTs indicating the success of the individual annotation reads. The errors correspond to the handles passed in server. This indicates whether the read succeeded in obtaining a defined annotation item. NOTE any FAILED error code indicates that the corresponding Annotation structure is undefined.

Return Value

The time domain of the request is defined by startTime and endTime. If endTime is less than startTime the data shall be returned in reverse order, with later data coming first.

If either startTime or endTime is given in string (relative) format, the absolute time of the OPCHDAtime structure (time) shall be set to the dateTime which the relative time was translated to by the server. OPC_S_NODATA is returned only if no annotations exist over the time domain.

Target Platforms: Windows 7/8/10, Windows Server 2008/2012/2016, .NET 4.x

Reference