System for controlling a plurality of equipments

摘要

A main control apparatus is connected to a single signal line. A plurality of equipments is respectively connected to a multipoint line. Each multipoint line diverges from the single signal line. The main control apparatus sends a control signal to each equipment through the single signal line using a frequency band. Each equipment receives the control signal from the main control apparatus through the multipoint line using the frequency band. Each equipment is assigned a unique frequency from within the frequency band.