This function reads the annotations from the history database in the specified time domain for the specified item IDs. This method is intended to read annotations for an item at specified timestamps. OPC_S_NODATA is returned only if no annotations exist over the time domain.
Syntax
| Visual Basic (Declaration) | |
|---|---|
Overloads Function ReadAnnotations( _ ByVal transactionID As Integer, _ ByVal startTime As Date, _ ByVal endTime As Date, _ ByVal serverHnd() As Integer, _ ByRef cancelID As Integer, _ ByRef errors As Integer() _ ) As Integer | |
| C# | |
|---|---|
int ReadAnnotations( int transactionID, DateTime startTime, DateTime endTime, int[] serverHnd, 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.
- serverHnd
- The list of server item handles for the annotation items to be read.
- cancelID
- Place to return a Server generated ID to be used in case the operation needs to be canceled.
- errors
- Array of HRESULTs indicating whether the corresponding server handle was valid.
Return Value
HRESULTS success/error code.Requirements
Target Platforms: Windows XP Professional, Windows Server 2003 family, Windows Vista, Windows 7, Windows Server 2008 family