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

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

Parameters

transactionID

An identifier created by the client and passed to the server in this call. The server shall return this identifier along with the results of this call.

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.

cancelID

OUT: Place to return a Server generated ID to be used in case the operation needs to be canceled.

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 values are returned.

The order of the data returned shall match the order of the ItemIDs in the request.

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

Reference