A display data packet contains identification information. A display unit communication system includes a control unit, a terminal adaptor to which a terminal adaptor ID is assigned and which is connected to the control unit, and a display unit to which a display unit ID is assigned and which is connected to the terminal adaptor in series and drives a display element according to the display data packet supplied from the control unit. The terminal adaptor receives a display data packet, the terminal adaptor ID of which agrees with that contained in the identification information, and transfers the display data packet to the display unit. The display unit receives the display data packet, the display unit ID of which agrees with that contained in the identification information, and drives the display element to display an image.