Vehicle-mounted device control system

A voltage regulator (6) of a power generator device (1) and an electronic control unit (5) are connected through a communication line (100). The voltage regulator (6) transmits power generator type identification information for specifying a type of the power generator device (1) to the electronic control unit (5). The electronic control unit (5) stores a plurality of control modes and selects one of the plurality of control modes based on the received power generator type identification information. The electronic control unit (5) outputs a control signal to the regulator (6) so that the voltage regulator (6) regulates power generating operation of the power generator device (1) in response to the control signal.