Patent ID: 8285445

Claim:
A system for performing communication between devices mounted in a vehicle which enables communication between an electronic control unit and different on-vehicle devices, said system comprising: a power line to which an electronic control unit and each of plural on-vehicle devices are connected, the power line being connected to a battery having a negative electrode and a positive electrode for power supply to the power line, the power line having a positive electrode side core wire connected to the positive electrode of the battery and a negative electrode side core wire connected to the negative electrode of the battery; and a communication module included in the electronic control unit and each of the on-vehicle devices, each communication module comprising: a connection unit transformer having two pairs of input-output terminals, wherein at least one of the positive electrode side core wire and the negative electrode side core wire is connected to a respective terminal of one pair of the input-output terminals of the transformer through a capacitor; and a signal processor connected to the other pair of input-output terminals of the transformer, adapted to convert analog signals from the power line and outputted from the other pair of input-output terminals, adapted to convert externally inputted digital signals into analog signals and adapted to transmit the converted analog signals to the other pair of input-output terminals of the transformer so that the converted analog signals are superimposed on the voltage of the power line in the connection unit.