As I understood, the DO channel is the output pin of the digital Arduino pins we use to drive the ultrassonic distance sensor, and with the stimulus pulse we can choose the polarity of that pulse. Is that correct ? when the say a non polarity, can be that in a pulse ?
since DO is optional, you can use the Square Wave.vi to generate a frequency, and measure pulse width with digital read pulse width.vi and place a jumper between arduino pins, just for learning purposes.
Jorge Augusto Pessatto Mondadori, PhD Sistema Fiep CLAD, CLD