Professional Edition only.
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.
'Usage
Dim instance As AppPlugin
Dim transactionID As Integer
Dim startTime As Date
Dim endTime As Date
Dim serverHnd() As Integer
Dim cancelID As Integer
Dim errors As Integer()
Dim value As Integer
value = instance.ReadAnnotations(transactionID, startTime, endTime, serverHnd, cancelID, errors)
public int ReadAnnotations(
int ,
DateTime ,
DateTime ,
int[] ,
out int ,
out int[]
)
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.
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2