Sampling Rate

One of the most important parameters of an analog input or output system is the rate at which the measurement device samples an incoming signal or generates the output signal. The sampling rate, which is called the scan rate in Traditional NI-DAQ (Legacy), is the speed at which a device acquires or generates a sample on each channel. A fast input sampling rate acquires more points in a given time and can form a better representation of the original signal than a slow sampling rate. Generating a 1 Hz signal using 1000 points per cycle at 1000 S/s produces a much finer representation than using 10 points per cycle at a sample rate of 10 S/s.

Sampling too slowly results in a poor representation of the analog signal. Undersampling causes the signal to appear as if it has a different frequency than it actually does. This misrepresentation of a signal is called aliasing.