This asynchronous function computes aggregate values, qualities, and timestamps from data in the history database for the specified time domain for one or more items.
The time domain is divided into subintervals of duration resampleInterval. The specified aggregate is calculated for each subinterval beginning with startTime by using the data within the next resampleInterval.
This function is intended to provide values calculated with respect to the resample interval. For example, this function can provide hourly statistics such as Maximum, Minimum, Average, et. al. for each item during the specified time domain when resampleInterval is 1 hour.
The results are returned via the client's ReadComplete event handler.
Overload List
| Overload | Description |
|---|---|
| ReadProcessed(Int32,OPCHDAtime,OPCHDAtime,TimeSpan,Int32[],Int32[],Int32,Int32[]) | This asynchronous function computes aggregate values, qualities, and timestamps from data in the history database for the specified time domain for one or more items. The time domain is divided into subintervals of duration resampleInterval. The specified aggregate is calculated for each subinterval beginning with startTime by using the data within the next resampleInterval. This function is intended to provide values calculated with respect to the resample interval. For example, this function can provide hourly statistics such as Maximum, Minimum, Average, et. al. for each item during the specified time domain when resampleInterval is 1 hour. The results are returned via the client's ReadComplete event handler. |
| ReadProcessed(OPCHDAtime,OPCHDAtime,TimeSpan,Int32[],Int32[],OPCHDAitem[],Int32[]) | This synchronous function computes aggregate values, qualities, and timestamps from data in the history database for the specified time domain for one or more items. The time domain is divided into subintervals of duration resampleInterval. The specified aggregate is calculated for each subinterval beginning with startTime by using the data within the next resampleInterval. This function is intended to provide values calculated with respect to the resample interval. For example, this function can provide hourly statistics such as Maximum, Minimum, Average, etc. for each item during the specified time domain when resampleInterval is 1 hour. |
Requirements
Target Platforms: Windows 7/8/10, Windows Server 2008/2012/2016, .NET 4.x