Patent ID: 6144927
Filing Date: 2000-11-07
Classification: F02D,G07B,G07C,H04L

Abstract:
A data transmission device for a motor vehicle, comprising a pulse generator, a monitoring unit, and two separate communication channels interconnecting said pulse generator with said monitoring unit, the pulse generator (1) containing a sensor element (2) for generating a first electric signal which is modulated in proportion to a speed of the vehicle, whereina) the pulse generator (1) comprises a circuit arrangement (3) outputting a modulated first signal by modulating the first signal of the sensor element (2) in a series of square pulses;b) the pulse generator (1) comprises a first memory for recording the square pulses, and a coding circuit (7) for coding a content of the first memory to ouput an encoded signal having data of the first signal;c) said pulse generator (1) and said monitoring unit (20) are connected to each other both by a signal line (9) of a first of said communication channels and by a data line (19) of a second of said communication channels;d) the signal line (9) transmits the modulated first signal of the sensor element (2) uncoded to the monitoring unit;e) the data line (19) transmits the encoded signal to the monitoring unit (20);f) the monitoring unit (20) has a second memory for recording the modulated first signal which is continuously transmitted via the signal line (9);g) the monitoring unit (20) comprises a logic unit (14) for decoding the encoded signal received over the data line (19) to produce a decoded signal; andh) the monitoring unit (20) further comprises a comparator 15 which, in combination with said logic unit (14), compares the decoded signal with the modulated first signal transmitted over the signal line (9) and stored in the monitoring unit (20) so as to verify validity of the modulated first signal with respect to a defined period of time.