I am having trouble understanding how the Sampling Frequency of the Low Pass Filter actually impacts the function buried within. The information passed in is an array with no relavance to time. How does the function actually sample this array of data at a frequency?
I doubt that they actually build a waveform. Here is my guess: By defining a sample frequency they can get the sampling interval dt as you indicated. By defining a sampling frequency the cutoff frequencies can be scaled to frequency units (Hz), making the VI easier to use.