A first wire connects a control device to a cable, and supplies a first power signal provided by the control device to the cable. First and second nodes are provided in the first wire. A second wire connects a driving device to the cable, and supplies a first power signal transmitted from the cable to the driving device. Third and fourth nodes are provided in the second wire. A power supplier is connected to the first node and supplies a second power signal. A power receiver is connected to the third node, and provides a second power signal supplied by the power supplier to a detection device. A first communication circuitry is connected to the fourth node. A second communication circuitry is connected to the second node, and transmits a communication signal to or receives a communication signal from the first communication circuitry.