Return in Hz the frequency of the last input pulse; Return in microseconds the width and period of the input pulses arriving at channel ch of the pulse-measurement pin. The pulse-measurement channel ch must have been enabled by the PMON statement already. If the pulses stop coming in then PULSEFREQUENCY will return a zero while the other two functions will saturate at a certain maximum value (for T100MD+ it is equivalent to about 3.28 seconds)