NI-DAQmx .NET Framework 4.5 API Reference

DigitalMultiChannelReader.BeginMemoryOptimizedReadSingleSampleMultiLine Method

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Updated2023-02-21
2 minute(s) read

Begins an asynchronous read of a single sample containing Boolean values from one or more DIChannel objects in a task. Each channel can contain multiple digital lines.

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

Syntax

public IAsyncResult BeginMemoryOptimizedReadSingleSampleMultiLine(
	AsyncCallback callback,
	Object state,
	bool[,] data
)

Public Function BeginMemoryOptimizedReadSingleSampleMultiLine ( 
	callback As AsyncCallback,
	state As Object,
	data As Boolean(,)
) As IAsyncResult

Parameters

callback: Type: SystemAsyncCallback
An optional asynchronous callback that is called when the read is complete. Specify if you do not want a callback when the read is complete.
state: Type: SystemObject
A user-provided object that distinguishes this asynchronous read request from other requests. Use this parameter to provide information to the callback. Specify if you do not need to pass any additional information to the callback.
data: Type: SystemBoolean
An initialized 2D array of Boolean 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 line in that channel. 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.

Return Value

Type: IAsyncResult
An IAsyncResult that represents the asynchronous call.

Remarks

If the data buffer is large enough to hold the number of samples requested, this overload attempts to reuse existing memory allocated from the array to acquire data. This results in more efficient memory allocation when performing multiple reads with a continuous digital input task.

To get the read data or any exceptions that occurred during an asynchronous read initiated with this method, call EndMemoryOptimizedReadSingleSampleMultiLine(IAsyncResult) with the returned IAsyncResult.

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.

Refer to NI-DAQmx Readers and Writers for more information about memory limitations in NI-DAQmx read methods.

Note
Refer to Asynchronous Reads and Writes for additional information.

NI-DAQmx .NET Framework 4.5 API Reference

Table of Contents

DigitalMultiChannelReader.BeginMemoryOptimizedReadSingleSampleMultiLine Method

Syntax

Parameters

Return Value

Remarks

See Also

Reference

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