Communication Monitoring System

Abstract

A system for monitoring of integrity of a communication bus includes a communication bus; at least one transmitter configured to generate and transmit a signal on the communication bus; at least one receiver configured to receive a signal generated by the transmitter and transmitted on the communication bus; and a database of the transmitter. The database includes at least: device identification; expected rate of data transmittance; and device relative location along the link. The receiver is configured to receive the transmitted signal as well as any reflected signals arising from non-impedance matched section in the communication bus. A fault condition is identified by the occurrence of any of: a difference of the duration of the transmitted pulse from the duration of the received pulse; a difference of the measured transmitter rate of data transmittance from the database rate of data transmission.

What is claimed is: 
     
         1 . A system for monitoring of integrity of a communication bus said system comprising:
 a communication bus;   at least one transmitter configured to generate and transmit a signal on the communication bus;   at least one receiver configured to receive a signal generated by the transmitter and transmitted on the communication bus; and   a database of said transmitter; wherein the database comprises at least: device identification; expected rate of data transmittance; and device relative location along the link;
 wherein the receiver is further configured to receive the transmitted signal as well as any reflected signals arising from non-impedance matched section in the communication bus; and 
 wherein a fault condition is identified by the occurrence of any of: a difference of the duration of the transmitted pulse from the duration of the received pulse; a difference of the measured transmitter rate of data transmittance from the database rate of data transmission. 
   
     
     
         2 . The system according to  claim 1 , wherein the communication bus is at least one of a group of buses consisting of CAN bus, Mil-Std-1553, and FlexRay. 
     
     
         3 . The system according to  claim 1 , wherein the signal reflected by the communication bus non impedance matched section is an attenuated, time delayed replica of the transmitted pulse. 
     
     
         4 . The system according to  claim 1 , wherein the non-impedance matched sections of the communication bus are either an open termination or short circuit termination, or connection to a local or global ground terminal. 
     
     
         5 . The system according to  claim 1 , wherein the signal width is determined by time difference between a level crossing of leading pulse edge and a level crossing of trailing signal tail. 
     
     
         6 . The system according to  claim 1 , wherein the transmitted signal is configured to have a rise time of less than 10 ns and at least twice as fast as a signal fall time of less than 40 ns. 
     
     
         7 . The system according to  claim 1 , wherein the transmitted signal is obtained from a combination of two symmetrical transmitters wherein each transmitter generates a signal with different signal rise and fall time. 
     
     
         8 . The system according to  claim 1 , wherein the transmitted signal is configured to have a rise time of less than 10 ns and a signal fall time of less than 40 ns. 
     
     
         9 . The system according to  claim 1 , wherein the transmitted signal is obtained from a combination of two symmetrical transmitters wherein each transmitter generates a signal with different signal rise and fall times.