ATEN US421A User manual

US221A/ US421A
USER MANUAL
USB 2.0 Peripheral Switch

FCC Information
This equipment has been tested and found to comply with the limits
for a Class B digital device, pursuant to Part 15 of the FCC Rules.
These limits are designed to provide reasonable protection against
harmful interference in a residential installation. This equipment
generates, uses and can radiate radio frequency energy, and if not
installed and used in accordance with the instruction manual, may
cause interference to radio communications. However, there is no
guarantee that interference will not occur in a particular installation. If
this equipment does cause harmful interference to radio or television
reception, which can be determined by turning the equipment off and
on, the user is encouraged to try to correct the interference by one or
more of the following measures:
Reorient or relocate the receiving antenna;
Increase the separation between the equipment and receiver;
Connect the equipment into an outlet on a circuit different from
that which the receiver is connected;
Consult the dealer or an experienced radio/television technician
for help.
RoHS
This product is RoHS compliant.
SJ/T 11364-2006
The following contains information that relates to China.

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US221A/ US421A
User Manual
Online Registration
You can register your product at our online support center:
Online Support
International
North America
International http://support.aten.com
North America http://www.aten-usa.com/product_registration
Email Support [email protected]
Online
Support
Technical Support http://support.aten.com
Troubleshooting
Documentation
Software Updates
http://www.aten.com
Telephone Support 886-2-8692-6959
Email Support ATEN TECH [email protected]
ATEN NJ [email protected]
Online
Support
Techn i c a l
Support
ATEN TECH http://www.aten-usa.com/support
ATEN NJ http://support.aten.com
Troubleshooting
Documentation
SW Updates
ATEN TECH http://www.aten-usa.com
ATEN NJ http://www.aten.com
Telephone Support ATEN TECH 1-888-999-ATEN
ATEN NJ 1-732-356-1703

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Package Contents
The US221A/ US421AUSB 2.0 Peripheral Switch package
contains the following items:
1 2-port (US221A) or 4-port (US421A) USB 2.0 Peripheral
Switch
1 1.8 m USB Type A to USB Type B Cable
1 Installation Disk
1 User Manual*
1 Quick Start Guide
Check to make sure that all the components are present and that
nothing got damaged in shipping. If you encounter a problem,
contact your dealer.
Read this manual thoroughly and follow the installation and
operation procedures carefully to prevent any damage to the unit,
and/or any of the devices connected to it.
*Features may have been added to the US221A/ US421Asince
this manual was printed. Please visit our website to download
the most up-to-date version of the manual.
Copyright © 2009 ATEN® International Co., Ltd.
Manual Part No. PAPE-1245-110G
Manual Date: 2009-05-20
ATEN and the ATEN logo are trademarks of ATEN International Co., Ltd. All rights
reserved. All other trademarks are the property of their respective owners.

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Overview
The US221A/ US421Ais a 2/4-port USB 2.0 Peripheral Switch
that allows up to 2/4 computers to share the use of a single USB
peripheral device (such as a printer, scanner, mass storage drive,
etc.*) on a one-at-a-time basis.
The peripheral focus can be given to a computer manually by
using pushbuttons on the switch or by using the software-based
configuration utility. In addition, the US221A/ US421Ahas a new
Auto Switch function that stores commands sent to the USB
peripheral device to be processed on a first-come, first-served
basis, meaning that a print server is not required.
Compatible with both Windows and Mac, and with multifunction
printer support, the US221A/ US421Ais the ideal way to share
the latest USB 2.0 peripherals in a multimedia SOHO
environment.
Note: The US221A/ US421Adoes not support a USB hub
peripheral device.

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Features
Enables two (US221A) or four (US421A) computers to share a
single USB peripheral device
Simple port selection via pushbuttons or easy-to-use
configuration utility
Auto Switch function – no need for a separate print server
USB 2.0 compliant
Supports transfer rates up to 480 Mbps
Multiplatform support – Windows and Mac
LED indicators display port focus
Overcurrent protection
Bus-powered
Hot pluggable
Buzzer indicates switching between computers
Supports multifunction printers

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System Requirements
Computers
The following equipment must be installed on each computer that
is to be connected to the system:
USB host controller
Cables
USB to USB cables to connect the computers to the
peripheral device.
Note: Only one USB Type A to USB Type B cable is provided
in the US221A/ US421Apackage. You will need to
purchase an additional USB Type A to USB Type B
cables for each computer you wish to connect to the
US221A/ US421A.
Operating Systems
Supported operating systems are shown in the table, below:
OS Version
Windows 2000, XP, 2003, 2008, Vista
Mac OS X 10.4.5, 10.5

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Components
Top View
1
2
3
2
1
3
4
4

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Rear View
No. Component Description
1 Lock LED Lights orange to show that the US221A/
US421Ais locked.
2 Port Selection
Pushbutton(s)
Pressing a Port Selection Pushbutton brings
control to the computer attached to its
corresponding port. See Manual Operation –
Pushbutton, page 12 for further details.
3 Port Selected
LEDs
Lights green to show that the computer
attached to its corresponding port has control.
4 Beeper On/Off
Switch (on side)
Use this recessed switch to turn the US221A/
US421A’s beeper on or off.
5 USB Type B
Computer Port
Your computers plug into these ports. See
Installation, page 10 for further details.
6 USB Type A
Peripheral Port
Your USB 2.0 peripheral device plugs into this
port.
5
6
5
6

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Installation
The US221A/ US421AUSB 2.0 Peripheral Switch provides 2/4
USB Type B ports for computers to connect to, and one USB
Type A port for the peripheral device (multifunction printer,
scanner, mass storage device, etc.) that the computers will
share.
To install the US221A/ US421A, do the following:
1. Use your USB device's USB cable to connect it to the
US221A/ US421A's USB Type A port.
2. Plug the USB Type B connector of the USB Type A to USB
Type B cable provided with the US221A/ US421Apackage
into any available port on the US221A/ US421A.
3. Plug the Type A connector into the computer’s USB host port.
Repeat steps 2 and 3 for any other computers you are installing.
Note: Only one USB Type A to USB Type B cable is provided in
the US221A/ US421Apackage. You will need to purchase
an additional USB Type A to USB Type B cables for each
computer you wish to connect to the US221A/ US421A.
1. Make sure that the power to any device that you
connect to the installation has been turned off and
that all devices are properly grounded.