ScopeChannelMeasurement.BeginFetchByte Method
- Updated2023-09-06
- 2 minute(s) read
ScopeChannelMeasurementBeginFetchByte Method
Begins an asynchronous retrieval of data from a previously initiated acquisition.
Namespace: NationalInstruments.ModularInstruments.NIScope
Assembly: NationalInstruments.ModularInstruments.NIScope.Fx45 (in NationalInstruments.ModularInstruments.NIScope.Fx45.dll) Version: 2023
Syntax
public IAsyncResult BeginFetchByte( PrecisionTimeSpan timeout, long numberOfSamples, AnalogWaveformCollection<byte> waveforms, AsyncCallback callback, Object asyncState )
Public Function BeginFetchByte ( timeout As PrecisionTimeSpan, numberOfSamples As Long, waveforms As AnalogWaveformCollection(Of Byte), callback As AsyncCallback, asyncState As Object ) As IAsyncResult
Parameters
- timeout
- Type: NationalInstrumentsPrecisionTimeSpan
The time to wait for data to be acquired. Using 0 for this parameter tells NI-SCOPE to fetch whatever data is currently available. Using MaxValue for this parameter implies infinite timeout. - numberOfSamples
- Type: SystemInt64
The maximum number of samples to fetch for each waveform. If the acquisition finishes with fewer points than requested, some instruments return partial data if the acquisition finished, was aborted, or a timeout of 0 was used. Use –1 for this parameter if you want to fetch all available samples. The method reads the actual record length and attempts to acquire all available samples. If it fails to complete within the timeout period, the method throws an exception. - waveforms
- Type: NationalInstrumentsAnalogWaveformCollectionByte
The waveform object whose memory can be reused while creating the output waveform. To allocate memory during the call to this method, set waveforms to . The method will also allocate memory during the call if waveforms is set to a waveform object with zero-sized data or waveforms is set to a waveform object with a different size than that required for the output waveform. For example, if waveforms is set to a waveform object with the same size as that required for this method call, then no new memory is allocated for the output waveform, and instead the memory of the waveform object from waveforms will be reused for the output waveform. - callback
- Type: SystemAsyncCallback
A delegate of type AsyncCallback, which will be invoked once the operation is complete. - asyncState
- Type: SystemObject
The state of the asynchronous operation.
Return Value
Type: IAsyncResultAn IAsyncResult that represents the asynchronous fetch, which could still be pending.
Remarks
Some functionality, such as time stamping, is not supported in all digitizers. Refer to Features Supported by Device for more information.