本发明系与从车辆来之电力供给停止之车载器进行通信。通信设备(200)系具备：发光组件(211)，其系向车载器(100)输出光能；及车辆信息接收部，其系经由天线(212)从车载器(100)接收车辆信息。车载器(100)系具备：通信电路，其系与通信设备(200)进行通信；及光电池(122)，其系将从通信设备(200)所供给之光能转换成电力，并将该电力供给至通信电路。车载器(100)之通信电路系具备：车辆信息存储部，其系将车辆信息非挥发性存储；及车辆信息发送部，其系将车辆信息存储部所存储之车辆信息发送至通信设备(200)。

Communication is established to a vehicle-mounted device without electricity supply from the vehicle. The communication device (200) includes: a light-emitting device (211) that emits light energy to the vehicle-mounted device (100); and a vehicle information reception device that receives a vehicle information through an antenna (212). The vehicle-mounted device (100) includes: a communication circuit that handles the communication with the communication device (200); and a photoelectric cell (122) that converts the light energy supplied from the communication device (200) to electricity and supplies the electricity to the communication circuit. The communication circuit of the vehicle-mounted device (100) includes: a vehicle information storing device that memorizes the vehicle information in a non-volatile manner; and a vehicle information transmitting device that transmits the vehicle information held in the vehicle information storing device to the communication device (200).