DAQmxWriteCtrFreq

int32 DAQmxWriteCtrFreq (TaskHandle taskHandle, int32 numSampsPerChan, bool32 autoStart, float64 timeout, bool32 dataLayout, float64 frequency[], float64 dutyCycle[], int32 *numSampsPerChanWritten, bool32 *reserved);

Purpose

Writes a new pulse frequency and duty cycle to each channel in a continuous counter output task that contains one or more channels.

Parameters

Input
Name	Type	Description
taskHandle	TaskHandle	The task to write samples to.
numSampsPerChan	int32	The number of samples, per channel, to write. You must pass in a value of 0 or more in order for the sample to write. If you pass a negative number, this function returns an error.
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.
dataLayout	bool32	Specifies how the samples are arranged, either interleaved or noninterleaved. Value Description DAQmx_Val_GroupByChannel Group by channel (noninterleaved) DAQmx_Val_GroupByScanNumber Group by sample (interleaved)
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.
Output
Name	Type	Description
numSampsPerChanWritten	int32 *	The actual number of samples per channel successfully written to the buffer.

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.