Patent ID: 6453250
Filing Date: 2002-09-17
Classification: H03K

Abstract:
A system for detecting missing pulses from a pulse train input signal by calculating and displaying maximum and minimum frequency values of pulses occurring during predetermined time periods comprising:an analog-to-digital converter for sampling said pulse train input signal to generate digital values representative thereof; a comparator for comparing said pulse train input signal and a threshold voltage to generate a comparison signal each time the amplitude of said pulse train input signal exceeds said threshold voltage; a histographical display for indicating the range of frequency values captured each of said predetermined time periods; and a microcontroller for receiving said digital values and identifying therefrom signal transitions indicative of rising and falling edges of said pulse train input signal and determining, based upon relative magnitudes of said rising and falling edges, said threshold voltage, for receiving the comparison signal and recording a corresponding time entry upon each receipt thereof, said microcontroller calculating maximum and minimum frequency values of the pulse train input signal during predetermined time periods based upon differences between the time entries, and passing said maximum and minimum frequency values to said histographical display for a simultaneous display of frequency values corresponding to the maximum and minimum frequency values, respectively, wherein spacial separation between the first and second frequency values is visually indicative of missing pulses within the time period.