To solve the problem that while a largely scaled plant control system such as a power plant or steelworks transmits a control instruction to a switching device to operate the ON/OFF of a driving motor through an exclusive communication network cable or metal cable, and acquires the operation information in a conventional manner, it is necessary to install large amounts of control cables in the plant having huge control signals, and to reduce construction costs and spaces.
In this system, a control unit connected to a first power line is provided with a first power line communication MODEM, and a switching device connected to a second power line for controlling a motor is provided with a second power line communication MODEM, and a control signal is input/output between the first and second power line communication MODEM through the first power line and the second power line.
Masuo Oiwa
Takenaka Ikuo
Keigo Murakami