To mount a vehicle equipment without modifying an electric system on a chassis side, or carrying out additional work thereto.

The communication device includes an ECU for a vehicle equipment provided inside a driver's cabin, and a local CAN to be connected with the vehicle equipment ECU. The vehicle equipment ECU includes: a connecting means for an operation switch for operating the vehicle equipment and an indicator for informing an operating condition of the vehicle equipment; a means for outputting an operation output of the operations switch to the local CAN; a means for outputting an indicator output to the indicator from the vehicle equipment transmitted through the local CAN; a means for collecting a predetermined vehicle information and outputting it to the local CAN; and a means for transmitting a vehicle control signal to the ECU from the vehicle equipment transmitted through the local CAN.