Detecting by USB client device a connection to host USB device wherein power is not supply from host USB device to USB client device

摘要

A USB host/client system includes a USB host device, a USB client device connected via a USB cable to the USB host device, and a power supply unit remote from the USB host device for powering the USB host device through the USB cable connecting the USB client device to the USB host device. The USB host device can have means for communicating with a computer while the USB host device is connected to a USB client device, and/or the power supply unit supplies sufficient power for all normal operations of the USB host device.