DAQmx Read (Analog 1D DBL 1Chan NSamp) VI

task/channels in is the name of the task or a list of virtual channels to which the operation applies. If you provide a list of virtual channels, NI-DAQmx creates a task automatically.

number of samples per channel specifies the number of samples to read.

If you leave this input unwired or set it to -1, NI-DAQmx determines how many samples to read based on if the task acquires samples continuously or acquires a finite number of samples.

If the task acquires samples continuously and you set this input to -1, this VI reads all the samples currently available in the buffer.

If the task acquires a finite number of samples and you set this input to -1, the VI waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the VI reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples.

timeout specifies the amount of time in seconds to wait for samples to become available. If the time elapses, the VI returns an error and any samples read before the timeout elapsed. The default timeout is 10 seconds. If you set timeout to -1, the VI waits indefinitely.

If you set timeout to 0, the VI tries once to read the requested samples and returns an error if it is unable to.

error in describes error conditions that occur before this VI or function runs.

The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. If an error occurs while this VI or function runs, the VI or function runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.

task out is a reference to the task after this VI or function runs. If you wired a channel or list of channels to task/channels in, NI-DAQmx creates this task automatically.

data returns a 1D array of samples. Each element in the array corresponds to a sample from the channel.

NI-DAQmx scales the data to the units of the measurement, including any custom scaling you apply to the channels. Use the DAQmx Create Virtual Channel VI or the DAQ Assistant to specify these units.

error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, error out describes the error status that this VI or function produces.

Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.