Method and system for communicating between a first piece of equipment and a second piece of equipment connected to the first piece of equipment via a single-conductor transmission line, wherein data (DATA1, DATA2) are transmitted from the first piece of equipment to the second piece of equipment by pulse width modulation of a transmission signal emitted on the transmission line, and wherein data are transmitted from the second piece of equipment to the first piece of equipment by amplitude modulation of said transmission signal.
