A robot system according to an aspect of embodiments includes a terminal part, a robot control unit, and a duplex signal line. The terminal part includes a connection terminal to which one or more external devices that output a plurality of signals can be connected. The robot control unit controls an operation of the robot in accordance with the signals from the external device(s). The duplex signal line connects the terminal part to the robot control unit and transmits the plurality of signals, input from the external device(s) into the terminal part, to the robot control unit via two routes. Moreover, the duplex signal line includes the two routes each of which collects the plurality of signals and transmits the signals with a signal line.