PURPOSE: To separately control power sources of plural terminal equipments which have been connected to one line, by analyzing an instruction from a main computer.

CONSTITUTION: Information which is sent from a main computer 1 contains a synchronizing code, a start code, an address, a control instruction, and an end code. In remote power source controllers 2-1...2-n for receiving the information, a means for analyzing the instruction, discriminating the address by the analysis, and controlling a power source of a terminal equipment of the corresponding address is contained, the information is received through a line branching device 4, analyzed and the address is discriminated, and in accordance with the control instruction, power sources of terminal equipments 3-1...3-n corresponding to the address are controlled separately by control signals 6-1...6-n.