A control method for sorting machines including carriages (2), each carriage including a loading-unloading device (3) which can be selectively activated for loading-unloading an object (O) from the carriage and an electronic unit (4) configured to receive and analyse a digital signal (20), includes the steps of: moving the carriage along a sorting direction having a plurality of loading stations (9) and unloading stations (10) each including respective inductors (11); generating by means of the inductors a magnetic field with a variable frequency modulating the digital signal uniquely associated with an operating mode selected from a plurality of operating modes, the digital signal including a bit string; transmitting, by electromagnetic induction, the digital signal to the electronic unit of the carriage; and activating the loading-unloading device according to operating mode uniquely associated with the received digital signal.