DAQmx - Data Acquisition VIs and Functions

January 2008, 370469L-01

Use the DAQmx - Data Acquisition VIs with NI-DAQ and NI-SWITCH hardware devices to develop instrumentation, acquisition, and control applications. Refer to the NI-DAQ Readme for a complete listing of devices that NI-DAQmx supports.

Palette Object	Description
DAQ Assistant Express VI	Creates, edits, and runs tasks using NI-DAQmx.
DAQmx Channel Property Node	A Property Node with the DAQmx Channel class preselected. Right-click the Property Node and choose Select Filter from the shortcut menu to make the Property Node show only the properties supported by a particular device installed in the system or supported by all devices installed in the system.
DAQmx Clear Task	Clears the task. Before clearing, this VI stops the task, if necessary, and releases any resources the task reserved. You cannot use a task after you clear it unless you recreate the task.
DAQmx Create Virtual Channel	Creates a virtual channel or set of virtual channels and adds them to a task. The instances of this polymorphic VI correspond to the I/O type of the channel, such as analog input, digital output, or counter output; the measurement or generation to perform, such as temperature measurement, voltage generation, or event counting; and in some cases, the sensor to use, such as a thermocouple or RTD for temperature measurements.
DAQmx Global Channel Constant	Lists all virtual channels you create and save using the DAQ Assistant. Select Browse to select multiple channels. Right-click the constant and select I/O Name Filtering from the shortcut menu to limit the channels that the constant displays and to limit what you can enter in the constant.
DAQmx Read Property Node	A Property Node with the DAQmx Read class preselected. Right-click the Property Node and choose Select Filter from the shortcut menu to make the Property Node show only the properties supported by a particular device installed in the system or supported by all the devices installed in the system.
DAQmx Read	Reads samples from the task or virtual channels you specify. The instances of this polymorphic VI specify what format of samples to return, whether to read a single sample or multiple samples at once, and whether to read from one or multiple channels.
DAQmx Start Task	Transitions the task to the running state to begin the measurement or generation. Using this VI is required for some applications and is optional for others.
DAQmx Stop Task	Stops the task and returns it to the state the task was in before the DAQmx Start Task VI ran or the DAQmx Write VI ran with the autostart input set to TRUE.
DAQmx Task Name Constant	Lists all tasks you create and save by using the DAQ Assistant. You cannot use this constant to select multiple tasks. Right-click the constant, and select I/O Name Filtering from the shortcut menu to limit the tasks that the constant displays and to limit what you can enter in the constant.
DAQmx Timing Property Node	A Property Node with the DAQmx Timing class preselected. Right-click the Property Node and choose Select Filter from the shortcut menu to make the Property Node show only the properties supported by a particular device installed in the system or supported by all the devices installed in the system.
DAQmx Timing	Configures the number of samples to acquire or generate and creates a buffer when needed. The instances of this polymorphic VI correspond to the type of timing to use for the task.
DAQmx Trigger Property Node	A Property Node with the DAQmx Trigger class preselected. Right-click the Property Node and choose Select Filter from the shortcut menu to make the Property Node show only the properties supported by a particular device installed in the system or supported by all the devices installed in the system.
DAQmx Trigger	Configures triggering for the task. The instances of this polymorphic VI correspond to the trigger and trigger type to configure.
DAQmx Wait Until Done	Waits for the measurement or generation to complete. Use this VI to ensure that the specified operation is complete before you stop the task.
DAQmx Write Property Node	A Property Node with the DAQmx Write class preselected. Right-click the Property Node and choose Select Filter from the shortcut menu to make the Property Node show only the properties supported by a particular device installed in the system or supported by all the devices installed in the system.
DAQmx Write	Writes samples to the task or virtual channels you specify. The instances of this polymorphic VI specify the format of the samples to write, whether to write one or multiple samples, and whether to write to one or multiple channels.

Subpalette	Description
DAQmx Advanced VIs and Functions	Use the DAQmx Advanced VIs and functions to access advanced and miscellaneous features of NI-DAQmx.
DAQmx Advanced Task Options VIs and Functions	Use the DAQmx Advanced Task Options VIs and functions for advanced configuration and control of tasks.
DAQmx Device Configuration VIs and Functions	Use the DAQmx Device Configuration VIs and functions for hardware-specific configuration and control.
DAQmx Real Time VIs and Function	Use the DAQmx Real Time VIs and function to configure and perform real-time operations.

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