PURPOSE: To supply electric power to a terminal equipment under the command of a center, and to supply the power to a timer and a register only during a halt of the terminal equipment, and to reduce the power consumption of the terminal equipment, by using a simple hardware consisting of the timer, register, and a power source for the timer.

CONSTITUTION: To the center 1 of a data communication system, a terminal equipment 4 is connected through modems 2 and 3, and the center 1 processes information from each terminal equipment 4 collectively. For the receiving circuit 11, receiving buffer 12, and discriminating circuit 13 for discriminating the contents of received data, each terminal equipment 4 is provided with a main body power source 17, an information processor 18, and an input and output equipment 19, and further provided with a timer power source 16 connected to a register 14 and a timer 15. Further, information on the time when the power source is turned on is contained in a powering-down command telegraphic message to be sent from the center 1 to the terminal equipment 4 and after the information is discriminated by the circuit 13, the respective devices are powered up by the power source 17 for the time set in the timer 15, thus reducing the power consumption of the terminal equipment 4.