摘要 |
A communication link between a tractor and trailer is established utilizing existing by dormant tractor and trailer circuitry. In one embodiment of the invention, a tractor communications device has a communications port connected to a turn signal circuit and a trailer communications device has a communications port connected to the same turn signal circuit. The two communications devices permit communications therebetween over the turn signal circuit as long as the turn signal circuit is inactive, and otherwise inhibits such communications. In another embodiment of the invention, such a communications link is used to transmit a fault signal, relating to an abnormally operating trailer anti-lock brake system (ABS), to the tractor for activation of an in-cab ABS warning device. |