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DAQmx Create Virtual Channel (Counter Input » Pulse Width) (G Dataflow)

Last Modified: July 19, 2019

Creates a channel to measure the width of a digital pulse. starting edge determines whether to measure a high pulse or low pulse. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this node because a task can contain only one counter input channel. To read from multiple counters simultaneously, use a separate task for each counter. Connect the input signal to the default input terminal of the counter unless you select a different input terminal.


task in

task in specifies the task to which to add the virtual channels this node creates. If you do not specify a task, NI-DAQmx creates a task for you, and adds the virtual channels this node creates to that task.



counter specifies the name of the counter to use to create the virtual channel. The DAQmx physical channel constant lists all physical channels, including counters, for devices installed in the system.


name to assign

name to assign specifies a name to assign to the virtual channel this node creates. If you do not wire a value to this input, NI-DAQmx uses the physical channel name as the virtual channel name.

If you use this input to provide your own names for the virtual channels, you must use the names when you refer to these channels in other NI-DAQmx nodes, such as the source input of the DAQmx Trigger node.

If you create multiple virtual channels with one DAQmx Create Virtual Channel node, you can specify a comma-separated list of names to assign to the virtual channels. If you provide fewer names than the number of virtual channels you create, NI-DAQmx automatically assigns names to the virtual channels.



units specifies the units to use to return time or period measurements.

Name Description
From Custom Scale

Units a custom scale specifies. If you select this value, you must wire a custom scale name to the custom scale name input.




Timebase ticks.


error in

error in describes error conditions that occur before this node runs. This input provides standard 'error in' functionality.


measurement range

measurement range specifies the minimum and maximum values you expect to measure.


maximum value

maximum value specifies in units the maximum value you expect to measure.


minimum value

minimum value specifies in units the minimum value you expect to measure.


custom scale name

custom scale name specifies the name of a custom scale for the channel.


starting edge

starting edge specifies on which edge to begin measuring pulse width.

Name Description

Begin measuring on the falling edge. The channel measures the width of low pulses.


Begin measuring on the rising edge. The channel measures the width of high pulses.


task out

task out is a reference to the task after this node runs. The task contains any newly created virtual channels. If you did not wire a value to task in, NI-DAQmx automatically creates the task this output refers to.


error out

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

Where This Node Can Run:

Desktop OS: Windows

FPGA: LabVIEW NXG does not support FPGA devices

Web Server: Not supported in VIs that run in a web application

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