AFData.SummariesAsync Method
- Last UpdatedNov 18, 2025
- 5 minute read
- PI System
- AF SDK 2024 R2
- Developer
Namespace: OSIsoft.AF.Data
Assembly: OSIsoft.AFSDK (in OSIsoft.AFSDK.dll) Version: 3.1.1.1182
Syntax
public Task<IDictionary<AFSummaryTypes, AFValues>> SummariesAsync( AFTimeRange timeRange, AFTimeSpan summaryDuration, AFSummaryTypes summaryType, AFCalculationBasis calculationBasis, AFTimestampCalculation timeType, CancellationToken cancellationToken = default )
Public Function SummariesAsync ( timeRange As AFTimeRange, summaryDuration As AFTimeSpan, summaryType As AFSummaryTypes, calculationBasis As AFCalculationBasis, timeType As AFTimestampCalculation, Optional cancellationToken As CancellationToken = Nothing ) As Task(Of IDictionary(Of AFSummaryTypes, AFValues)) Dim instance As AFData Dim timeRange As AFTimeRange Dim summaryDuration As AFTimeSpan Dim summaryType As AFSummaryTypes Dim calculationBasis As AFCalculationBasis Dim timeType As AFTimestampCalculation Dim cancellationToken As CancellationToken Dim returnValue As Task(Of IDictionary(Of AFSummaryTypes, AFValues)) returnValue = instance.SummariesAsync(timeRange, summaryDuration, summaryType, calculationBasis, timeType, cancellationToken)
public: Task<IDictionary<AFSummaryTypes, AFValues^>^>^ SummariesAsync( AFTimeRange timeRange, AFTimeSpan summaryDuration, AFSummaryTypes summaryType, AFCalculationBasis calculationBasis, AFTimestampCalculation timeType, CancellationToken cancellationToken = CancellationToken() )
member SummariesAsync : timeRange : AFTimeRange * summaryDuration : AFTimeSpan * summaryType : AFSummaryTypes * calculationBasis : AFCalculationBasis * timeType : AFTimestampCalculation * ?cancellationToken : CancellationToken (* Defaults: let _cancellationToken = defaultArg cancellationToken new CancellationToken() *) -> Task<IDictionary<AFSummaryTypes, AFValues>>
Parameters
- timeRange
- Type: OSIsoft.AF.TimeAFTimeRange
The bounding time range over which the summary intervals are computed. - summaryDuration
- Type: OSIsoft.AF.TimeAFTimeSpan
The duration of each summary interval. If specified in hours, minutes, seconds, or milliseconds, the summary durations will be evenly spaced UTC time intervals. Longer interval types are interpreted using wall clock rules and are time zone dependent. For example, an interval created with the string "24h" means using an evenly spaced 24 UTC hour interval between each event. On the other hand, an interval created with the string "1d" would return an interval shorter or longer than 24 hours if the interval encompasses a Daylight Savings Time change.
When a positive duration is specified, the summary calculation begins at the earliest bounding time in the timeRange and applies the duration repeatedly in time ascending direction to generate the summary intervals.
If a negative duration is specified, the summary calculation begins at the latest bounding time in the timeRange and applies the duration repeatedly in time descending direction to generate the summary intervals. Note that the order of values returned will still be reflected by the timeRange, regardless of the summary duration sign.
- summaryType
- Type: OSIsoft.AF.DataAFSummaryTypes
A flag which specifies one or more summaries to compute for each interval over the time range - calculationBasis
- Type: OSIsoft.AF.DataAFCalculationBasis
Specifies the method of evaluating the data over the time range. - timeType
- Type: OSIsoft.AF.DataAFTimestampCalculation
A flag indicating what how to calculate a timestamp for each interval. - cancellationToken (Optional)
- Type: System.ThreadingCancellationToken
A cancellation token used to abort processing before completion. Passing the default CancellationToken.None will run to completion or until the PIConnectionInfo.OperationTimeOut period elapses.
Return Value
Type: TaskIDictionaryAFSummaryTypes, AFValuesReturns a task whose result is a dictionary of AFValues, indexed by the specific AFSummaryTypes.
Exceptions
| Exception | Condition |
|---|---|
| AggregateException | Asynchronous methods throw AggregateException on failure which will contain one or more exceptions containing the failure. |
Remarks
| This method, property, or class is not available in the legacy .NET 3.5 version of the SDK. |
| You must have ReadData security rights to read a data value. |
| This call might use a background task to complete some of its work. See the Threading Overview for some matters to consider when execution transitions to another thread. |
| Asynchronous data calls in AF SDK attempt to do as much work as possible asynchronously. If no work can be done asynchronously, then the SupportedDataMethods will report that asynchronous calls are not supported. If an attribute uses a Formula or other calculated data reference has any input that supports asynchronous calls, then the attribute will support asynchronous calls. When making an asynchronous data call, input data will be acquired asynchronously when possible or synchronously otherwise. Data calls that require partitioning across versions will always fall back to synchronous calls. |
| Impersonation of AF SDK asynchronous calls relies on the .NET framework's built-in support for flowing execution context across asynchronous points. When making these calls while impersonating, the thread or runtime must be configured to propagate the impersonation across these asynchronous points (see the SecurityContext documentation for details). |