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AFDataEndOfStreamAsync Method

Get the value with the largest timestamp for a data stream.

Namespace:  OSIsoft.AF.Data
Assembly:  OSIsoft.AFSDK (in OSIsoft.AFSDK.dll) Version: 2.10.6.195
Syntax
public Task<AFValue> EndOfStreamAsync(
	UOM desiredUOM,
	CancellationToken cancellationToken = null
)

Parameters

desiredUOM
Type: OSIsoft.AF.UnitsOfMeasureUOM
The desired unit of measure for the returned value. If , then the value is returned in the unit of measure specified by the associated attribute's DefaultUOM property.
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: TaskAFValue
Returns a task whose result is the AFValue for the attribute. If AFValue.IsGood returned by the data reference is , then the returned value is converted to the proper UOM and Type. The timestamp of the value will indicate the time of the last recorded event. In the case of calculation based data references, it will normally indicate the latest input value's end-of-stream timestamp.
Exceptions
ExceptionCondition
AggregateException Asynchronous methods throw AggregateException on failure which will contain one or more exceptions containing the failure.
Remarks

Note Notes to Callers
This method, property, or class is only available in the .NET 4 version of the SDK.

Security note Security Note
You must have ReadData security rights to read a data value.

Note Notes to Callers
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.

Important note Important
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.

Important note Important
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).

Version Information

AFSDK

Supported in: 2.10.5, 2.10, 2.9.5, 2.9, 2.8.5, 2.8
See Also
Enabling Operational Intelligence