Train fault monitoring system

A monitoring system for monitoring faults of a plurality of functions in each rail road car of a train from the lead car comprising:

• a digital electronic master unit located in said lead car for scanning each car in sequence from a first car of said train to a last car of said train to monitor one identical function in each car and repeating said scanning sequence for a next identical function until the plurality of functions are all scanned, by transmitting a sequence of electrical pulses one at a time and receiving electrical acknowledging pulses which represent the car and the function being monitored, said master unit comprising indicating means which indicates said car and said function being monitored in the absence of an acknowledging pulse being received by said master unit to indicate a fault condition;
• first counting means for counting each said transmitting pulse in said scanning sequence, the instantaneous sum of said counted pulses determining which one of said cars is being monitored, and said counting means being reset when said instantaneous sum becomes greater than the maximum number of cars adaptable by said monitoring system;
• second counting means for determining which identical function in each car in said scanning sequence is being monitored based upon the sum of the instantaneous count of said second counting means, said count of said second counting means being incremented to indicate a next identical function by said first counting means when said instantaneous sum of said first counting means becomes greater than the maximum number of cars adaptable by said monitoring system and said master unit switching to a stop mode by discontinuing the transmission of said transmitting pulses with the instantaneous sum of said second counting means becomes greater than the maximum number of functions provided in said monitoring system;
• decoder means for receiving said first and second counts for determining which car and which function is being monitored, said decoder means actuating said indicating means in the absence of an acknowledging pulse;
• a respective digital car unit located in each rail road car for receiving said transmitting pulses from said master unit and returning an acknowledging pulse, each car unit have selector means set to a count different from the other selector means on other cars for transmitting an acknowledging pulse only when the count of a first counting means of said car unit corresponds with the selected count on said selector means and the said acknowledging pulse is transmitted through one of the channels selected by a second counting means of said car unit and said channel corresponds to one of the monitorable functions of a car;
• a respective functional relay assembly located on each car for monitoring said plurality of functions on each car and transmitting or not transmitting said acknowledging pulses from said car unit depending upon whether the selected function being monitored has a fault condition;
• means running the length of the train and connecting said master unit, said car unit and said functional relay assembly for transmitting said transmitting and acknowledging pulses.