摘要 |
A communication system includes: a master device; and slave devices communicating with the master device via a transmission line. The master device includes: an electric power supply unit for outputting an electric power supply signal having one specific frequency to the transmission line; a master communication unit for communicating with each slave device through a communication signal; and an electric power supply frequency setting unit for setting the one specific frequency. Each slave device includes: an electric power supply signal input and output unit for retrieving the electric power supply signal having a set frequency from the transmission line; a communication signal input and output unit for receiving and transmitting the communication signal to the transmission line; a slave communication unit for communicating with the master device through the communication signal; and a power source for energizing the slave communication unit according to the electric power supply signal. |