Sun Microsystems Sun Fire V480, Руководство администратора

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52 Sun Fire V480 Server Administration Guide • February 2002
About the USB Ports
The system’s back panel provides two external Universal Serial Bus (USB) ports for
connection to USB peripheral devices such as:
■
Sun Type-6 USB keyboard
■
Sun opto-mechanical three-button USB mouse
■
Modems
■
Printers
■
Scanners
■
Digital cameras
For USB port locations, see “Locating Back Panel Features” on page 20.
The USB ports are compliant with the Open Host Controller Interface (Open HCI)
specification for USB Revision 1.0. Both ports support isochronous and
asynchronous modes. The ports enable data transmission at speeds of 1.5 Mbps and
12 Mbps. Note that the USB data transmission speed is significantly faster than that
of the standard serial ports, which operate at a maximum rate of 460.8 Kbaud.
The USB ports are accessible by connecting a USB cable to either back panel USB
connector. The connectors at each end of a USB cable are different, so you cannot
connect them incorrectly. One connector plugs in to the system or USB hub; the other
plugs in to the peripheral device. Up to 126 USB devices can be connected to the bus
simultaneously, through the use of USB hubs. The Universal Serial Bus provides
power for smaller USB devices such as modems. Larger USB devices, such as
scanners, require their own power source.
Both USB ports support hot-plugging. You can connect and disconnect the USB cable
and peripheral devices while the system is running, without affecting system
operations. However, you can only perform USB hot-plug operations while the
operating system is running. USB hot-plug operations are not supported when the
system
ok
prompt is displayed.