a method for transmitting logical information from a transmitter to a receiver via a single line , the receiver being connected to the transmitter by the line , the receiver placing a first signal on the line and the first signal being made up of alternating recessive and dominant levels , the transmitter placing a second signal on the line and the second signal being superposed on the line by the transmitter at least in the segments in which the first signal has a recessive level , the second signal being made up of a sequence of recessive and dominant levels , and the receiver determining from the second signal the logical information that is to be received .