Creates a channel to count the number of rising or falling edges of a digital signal. With the exception of devices that support multi-counter tasks, you can create only one counter input channel at a time with this VI 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.


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Inputs/Outputs

  • ci32.png edge —

    edge specifies on which edges of the input signal to increment or decrement the count.

    Falling (10171)

    Count falling edges.

    Rising (10280)

    Count rising edges.

  • ci32.png count direction —

    count direction specifies whether to increment or decrement the counter on each edge.

    Count Down (10124)

    Decrement counter.

    Count Up (10128)

    Increment counter.

    Externally Controlled (10326)

    The state of a digital line controls the count direction. Each counter has a default count direction terminal.

  • cu32.png initial count —

    initial count is the value from which to start counting.

  • cgenclassrntag.png task in —

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

  • cdaqmxscale.png counter —

    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.

  • cstr.png name to assign —

    name to assign specifies a name to assign to the virtual channel this VI 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 VIs and Property Nodes, such as the source input of the DAQmx Trigger VI.

    If you create multiple virtual channels with one DAQmx Create Virtual Channel VI, 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.

  • cerrcodeclst.png error in —

    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.

  • igenclassrntag.png task out —

    task out is a reference to the task after this VI 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.

  • ierrcodeclst.png error out —

    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.