int32 DAQmxReadCounterF64 (TaskHandle taskHandle,
int32 numSampsPerChan, float64 timeout, float64 readArray, uInt32
arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads multiple floating-point samples from a
counter task. Use this function when counter samples are scaled to
a floating-point value, such as for frequency and period
||The task to read samples from.
||The number of samples, per channel, to read. The
default value of -1 (DAQmx_Val_Auto) reads all available samples. If
readArray does not contain enough space, this
function returns as many samples as fit in
NI-DAQmx determines how many samples to read based on whether the
task acquires samples continuously or acquires a finite number of
If the task acquires samples continuously and you set this
parameter to -1, this function reads all the samples
currently available in the buffer.
If the task acquires a finite number of samples and you set this
parameter to -1, the function waits for the task to
acquire all requested samples, then reads those samples. If you set
the Read All Available Samples property to TRUE, the function reads
the samples currently available in the buffer and does not wait for
the task to acquire all requested samples.
||The amount of time, in seconds, to wait for the
function to read the sample(s). 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 read the requested samples.
If all the requested samples are read, the function is successful.
Otherwise, the function returns a timeout error and returns the
samples that were actually read.
||The size of the array, in samples, into which
samples are read.
||Reserved for future use. Pass NULL to this
||The array to read samples into.
||The actual number of samples read from each