Universal Serial Bus Usage Tables for HID Power Devices

Universal Serial Bus Usage Tables for HID Power Devices
Release 1.0 November 1, 1997 9
1. Introduction
This document defines the communication of Power Source Devices within the Universal Serial Bus (USB)protocol as a Human Interface Device (HID).
Various devices can have integrated hardware power control of internal components and/or batteries. The same functionality can also be associated with devices powered from external power sources, such as uninterruptible power supplies (UPS). In either case, status and control communication within the USB protocol is desirable for energy conservation, reset, and/or system shutdown.
1.1 Scope
This document fully describes HID usages for USB Power Devices.
The USB Power Device protocol was designed within the framework of the USB Human Interface Device(HID) Class specification. The Power Device builds on the foundation provided by a HID Class driver in the host environment. This allows Power Device drivers to be simpler because they can rely on the HID Class driver for direct access to their devices and don’t need to be concerned with the interaction between the HID Class driver and lower system software layers.