A terminal of a plurality of terminals that is located at the farthest position from a host has a return signal generator section, the return signal generator section transmits a return signal at a timing when data transmitted from the host to the terminals arrives at the terminal located at the farthest position, the return signal is returned to the host successively passing through interfaces of the terminals connected to a data bus, and each terminal originates data to be transmitted from the terminal to the host or from the terminal to a particular another terminal in synchronization with the return signal and delivers the data from the terminals to the host or the terminal in synchronization with the return signal.