This method computes the aggregate values, qualities, and timestamps from the history database from the specified start time at the interval for one or more items. This method is intended to be used to update the client software with new data as it becomes available; e.g., update a trend with new data on a periodic basis. The results are returned via the client's IOPCHDA_DataCallback::OnDataChange method.
'Usage
Dim instance As IAppPlugin
Dim transactionID As Integer
Dim startTime As Date
Dim interval As TimeSpan
Dim serverHandles() As Integer
Dim aggregates() As Integer
Dim numIntervals As Integer
Dim cancelID As Integer
Dim errors As Integer()
Dim value As Integer
value = instance.AdviseProcessed(transactionID, startTime, interval, serverHandles, aggregates, numIntervals, cancelID, errors)
int AdviseProcessed(
int ,
DateTime ,
TimeSpan ,
int[] serverHandles,
int[] ,
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.
- interval
- Interval between returned values.
- serverHandles
- The list server item handles for the items to be read.
- aggregates
- The list of aggregate values to be returned.
- numIntervals
- Number of resample intervals between updates.
- 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