DAQmxWriteCtrFreqScalar

NI-DAQmx C Functions

DAQmxWriteCtrFreqScalar

int32 DAQmxWriteCtrFreqScalar (TaskHandle taskHandle, bool32 autoStart, float64 timeout, float64 frequency, float64 dutyCycle, bool32 *reserved);

Purpose

Writes a new pulse frequency and duty cycle to a continuous counter output task that contains a single channel.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to write the sample to.
autoStart bool32 Specifies whether or not this function automatically starts the task if you do not start it.
timeout float64 The amount of time, in seconds, to wait for this function to write all the samples. The default value is 10.0 seconds. To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses.
A value of 0 indicates to try once to write the submitted samples. If this function successfully writes all submitted samples, it does not return an error. Otherwise, the function returns a timeout error and returns the number of samples actually written.
frequency float64 Specifies at what frequency to generate pulses.
dutyCycle float64 The width of the pulse divided by the pulse period. NI-DAQmx uses this ratio, combined with frequency, to determine both pulse width and pulse delay.
reserved bool32 * Reserved for future use. Pass NULL to this parameter.

Return Value

Name Type Description
status int32 The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error.