Device for connecting two pieces of equipment via an Ethernet link, and a docking station for such a piece of equipment

A method for transmitting data between a first electronic equipment and a second electronic equipment connected together by a connection device comprising first and second Ethernet type interfaces that are linked together by an up line and a down line linked to a respective one of the first and second electronic equipment, first and second power supply modules, each associated with a respective one of the first and second electronic equipment and wired in common mode between the up and down lines in order to transmit a power supply carrier signal in alternating current, and first and second secondary transmission modules, each associated with a respective one of the first and second power supply modules, wherein the second Ethernet type interface is linked to the up and down lines via a first transformer, the second power apply module receives power from a primary of the first transformer via a second transformer, and the second secondary transmission module receives power from a primary of the second transformer and is separately connected to the second power supply module, said method comprising a step of transmitting data in differential mode through the up line and the down line, a step of generating the power supply carrier signal by controlling the second power supply module by the second secondary transmission module, and a step of transmitting data by modulating the power supply carrier signal in accordance with a data stream, wherein the second secondary transmission module controls the second power supply module.