| 摘要 |
<p>PROBLEM TO BE SOLVED: To grasp the state of power supply for a printer correctly on the host computer side. SOLUTION: The power supply monitor grasps on/off state of the power supply for a printer connected with a host computer to perform bilateral communication on the host computer side. The power supply monitor comprises a power supply state informing means 12 provided in the printer 10 to receive an acknowledge signal from the host computer 20 and a binary signal being switched by the on/off state of the power supply for the printer and to deliver a response signal to the host computer upon receiving an acknowledge signal from the host computer 20 when the power supply for the printer is turned off while being driven by potential variation based on an acknowledge signal, and means 21 provided in the host computer in order to determine the on/off state of the power supply for the printer upon receiving the response signal.</p> |
