| 摘要 |
<p>PURPOSE:To connect a power supply to a terminal device only for data communication automatically and to save power consumption of a data transmitter, by using an output signal of a network controller and controlling the power supply of the data terminal device. CONSTITUTION:When a calling is received from an opposing station at a network controller 1 connected to a public communication line 6, a callout signal CI is outputted to a modulation and demodulation device (MODEM) 2. The signal CI from the device 2 is inputted to a power supply controller 3 as it is, the controller 3 detects the signal CI a callout signal CI1 is outputted to the device 2, and a callout signal CI2 is outputted to a data terminal device 4 from the device 2 and also the signal CI2 is applied to the controller 3 at the same time. When the signals CI and CI2 exist at the same time with the controller 3, the power supply 5 for the device 4 is applied. The device 2 receives a ready signal ER from the device 4, the line 6 is switched from the device 1 to the device 2 for communication. When the communication is finished, the signal ER is kept turn-off, the turning-off of the signal ER is detected with the controller 3 to interrupt the supply of the power supply 5.</p> |
