Patent ID: 8156254

Claim:
A method for exchanging data between an electronic payment terminal and a first system or a second system, the terminal comprising a USB connection terminal comprising at least one first data transfer wire, a first resistor connecting the first wire to a first source of a first voltage, and a switch between the first wire and the first resistor or between the first resistor and the first source, the first system comprising a first communication unit, a second wire connected to the first communication unit and intended to be connected to the first wire and a second resistor connecting the second wire to a second source of a second voltage strictly smaller than the first voltage and the second system comprising a second communication unit and a third wire connected to the second communication unit and intended to be connected to the first wire and a third resistor connecting the third wire to a third source of a third voltage strictly greater than the second voltage, the first and second communication units being adapted to initiate a data exchange with the electronic payment terminal, the method comprising the steps of: having the electronic payment terminal turn off the switch to allow for a data exchange between the electronic payment terminal and the second system; and having the electronic payment terminal turn on the switch to allow for a data exchange between the electronic payment terminal and the first system.