Patent ID: 8103413

Claim:
A communications network of a passenger protection system having a passenger protection device, which protects passengers at time of vehicle collision, the communications network comprising: a plurality of sensors including respective capacitors, which are electrically chargeable; and an electronic control unit configured to control the passenger protection device and bus-connected to the sensors to control charging of the capacitors so that the sensors respond by electric charge of the capacitors, the electronic control unit configured to control initialization of the sensors by controlling a state, in which an idle phase time period for charging the capacitors and a signal phase time period for receiving responses of the sensors are alternately repeated, the electronic control unit including a first memory circuit for storing a plurality of waveform generation data provided in correspondence to the sensors differently one another so that the capacitors produce different idle phase waveforms corresponding to the stored waveform generation data, and a communications control circuit for controlling respective charging of the sensors in the idle phase time period in accordance with the stored waveform generation data, and each of the sensors including a second memory circuit for storing a parameter data corresponding to the stored waveform generation data provided thereto, a detection circuit for detecting a parameter data of the idle phase waveform of the capacitor, and a response circuit for responding to the electronic control unit in the signal phase time period when the detected parameter data of the idle phase waveform corresponds to the stored parameter data of the idle phase waveform.