DAQmxReadCounterScalarF64

NI-DAQmx C Functions

DAQmxReadCounterScalarF64

int32 DAQmxReadCounterScalarF64 (TaskHandle taskHandle, float64 timeout, float64 *value, bool32 *reserved);

Purpose

Reads a single floating-point sample from a counter task. Use this function when the counter sample is scaled to a floating-point value, such as for frequency and period measurement.

Parameters

Input
Name Type Description
taskHandle TaskHandle The task to read the sample from.
timeout float64 The amount of time, in seconds, to wait for the function to read the sample(s). 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 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.
reserved bool32 * Reserved for future use. Pass NULL to this parameter.
Output
Name Type Description
value float64 * The sample read from the task.

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.