NI-DAQmx .NET Framework 4.5 API Reference

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Table of Contents

DigitalMultiChannelReader.EndMemoryOptimizedReadMultiSamplePortUInt16 Method

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  • Updated2023-02-21
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DigitalMultiChannelReader.EndMemoryOptimizedReadMultiSamplePortUInt16 Method
Handles the end of an asynchronous read initiated with BeginMemoryOptimizedReadMultiSamplePortUInt16(Int32, AsyncCallback, Object, UInt16) and retrieves the read samples.

Namespace:  NationalInstruments.DAQmx
Assembly:  NationalInstruments.DAQmx (in NationalInstruments.DAQmx.dll) Version: 20.7.45.49302

Syntax

public ushort[,] EndMemoryOptimizedReadMultiSamplePortUInt16(
	IAsyncResult asyncResult,
	out int actualNumberOfSamplesPerChannelRead
)
Public Function EndMemoryOptimizedReadMultiSamplePortUInt16 ( 
	asyncResult As IAsyncResult,
	<OutAttribute> ByRef actualNumberOfSamplesPerChannelRead As Integer
) As UShort(,)

Parameters

asyncResult
Type: SystemIAsyncResult
An IAsyncResult that represents an asynchronous call started by calling BeginMemoryOptimizedReadMultiSamplePortUInt16(Int32, AsyncCallback, Object, UInt16).
actualNumberOfSamplesPerChannelRead
Type: SystemInt32
The actual number of samples per channel read. This is useful when the reading operation yields fewer samples than the actual length of data.

Return Value

Type: UInt16
A 2D array of 16-bit unsigned integer samples that contains the read data. Each element in the first dimension of the array corresponds to a channel in the task. Each element in the second dimension of the array corresponds to a sample from each of the channels. The order of the channels in the array corresponds to the order in which you add the channels to the task or to the order of the channels you specify in ChannelsToRead.

Exceptions

ExceptionCondition
ArgumentException
  1. If data is or is uninitialized;
  2. If the first dimension of data does not match the number of channels;
  3. If ReallocationPolicy is not ToGrow, and data is not capable of holding the required number of samples; or
  4. For asynchronous reads, if asyncResult is or is not an instance of IAsyncResult returned from a call to BeginMemoryOptimizedReadMultiSamplePortUInt16(Int32, AsyncCallback, Object, UInt16).
DaqExceptionThe NI-DAQmx driver returned an error during the asynchronous operation.
OutOfMemoryExceptionThere is not enough memory to carry out this operation.

Remarks

If you call this method before the asynchronous read IAsyncResult is complete, it waits for the read to complete before returning.

NI-DAQmx scales the returned data to the units of the measurement, including any custom scaling you apply to the channel. You specify these units with the create channel methods or the DAQ Assistant.

NI-DAQmx read and write methods time out after the amount of time specified by the Timeout property on the task you are reading from or writing to.

Note Note
Refer to Asynchronous Reads and Writes for additional information.

See Also

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