Digital data link for truck weighing applications

An apparatus for communicating a continuous electrical signal representing a vehicle parameter to a location remote and apart from where the vehicle parameter is measured, the said apparatus comprising:

• (a) means periodically converting the continuous electrical signal into an N-bit digital code representative of the vehicle parameter;
• (b) means converting said N-bit digital code to an M-bit digital code and said means further outputting a digital signal therefrom;
• (c) a transmitter in communication with a demodulator by a hardwire link disposed along the length of the vehicle, the hardwire link being a portion of the vehicle's existing wiring, said transmitter transmitting said digital signal through said existing wiring to said demodulator disposed at a location remote from where the vehicle parameter was measured;
• (d) means periodically converting said M-bit digital code representative of the vehicle parameter received by said demodulator into a continuous signal representative of the vehicle parameter;
• (e) visual display means whereby the continuous signal representative of the vehicle parameter is displayed in a user viewable form;
• and,
• (f) means enabling a predetermined and known continuous analog signal simulating the electrical signal representing the vehicle parameter to be measured and switchable therewith to be periodically converted into an additional signal thereby providing calibration for the apparatus.