3Com 005605-00 User manual

This manual covers installation and operating instructions for the following 3Com modems:
U.S. Robotics 56 Kbps∗Voice internal and external modems
3Com, the 3Com logo, and U.S. Robotics are registered trademarks and Connections, RapidComm, and
x2 are trademarks of 3Com Corporation or its subsidiaries. Windows is a registered trademark of
Microsoft Corp. CompuServe is a registered trademark of CompuServe Inc. America Online is a
registered trademark of America Online Inc. Any other trademarks, trade names, or service marks used
in this manual are the property of their respective owners.
© 1998 3Com Corporation
7770 North Frontage Road
Skokie, IL 60077-2690
All Rights Reserved
∗∗ IMPORTANT! In accordance with the ITU-T standard for 56K transmissions, this modem is capable of
56 Kbps downloads. However, due to FCC rules which restrict power output of the service providers’
modems, current download speeds are limited to 53 Kbps. Actual speeds may vary depending on line
conditions and other factors. Uploads from users to server equipment travel at speeds up to 31.2 Kbps.
An analog phone line compatible with the ITU-T 56K standard or x2technology, and an Internet
provider or corporate host site compatible with the ITU-T 56K standard or x2 technology are necessary
for these high-speed downloads.

TABLE OF CONTENTS
Welcome to 56K Information Access 1
Product Features 2
Before You Begin (Windows 95 Users) 3
Determining Available Resources 3
Determining Your Version of Windows 95 4
Internal Modem Installation with Windows 3.x 5
A Word about COM Ports and IRQs 5
How to Use ComTest to Determine Your Modem’s Settings 7
Testing an Installed Modem 9
What to Do with ComTest’s Recommendation 10
How to Change the Modem’s Settings 12
How to Insert the Modem into the Computer 14
Internal Modem Installation with Windows 95 21
How to Prepare for Plug and Play Installation 22
How to Insert the Modem into the Computer 23
Installing the Modem Drivers 27
External Modem Installation with Windows 95 35
Determining Which Serial Cable to Buy 35
Connecting the Modem to the Computer 37
Installing the Modem Drivers 39

TABLEOFCONTENTS
Software Installation 47
Running the Setup Wizard 47
Using Connections 48
Installing the RapidComm™ Voice Fax/Data/Voice Software 48
Installing Other Fax/Data Software 50
Type of Modem 50
Initialization String 50
Flow Control 51
UART (External Modems Only) 51
Using Modem Station 52
What Does Modem Station Do? 52
Why Modem Station? 52
Installing Modem Station 52
Starting Modem Station 55
Using Detect New Modems 57
Using Terminal 58
Using Modem Configurator 60
Using Modem to Computer 63
Using the Extended Information Screens 67

TABLEOFCONTENTS
U.S. Robotics Modem Update Wizard 74
Installing the Wizard 74
Updating Your Modem 75
Troubleshooting and Online Help Resources 76
RapidComm Voice Troubleshooting Tips 82
If Plug and Play Does Not Detect Your Modem 83
Online Help Resources 84
Are You Still Having Problems? 87
If You Need to Return the Modem to Us for Repair 87
Glossary 88
Regulatory Information 102
Manufacturer’s Declaration of Conformity 102
Limited Warranty 109

WELCOME TO 56K* INFORMATION ACCESS
1
The International Telecommunications Union
(ITU) determines the technical protocols
communications devices must use to
interoperate with each other. Modems that
comply with ITU standards can “talk” to other
standards-compliant modems and fax
machines worldwide.
The ITU has determined a worldwide standard
for 56K modem technology . With a U.S.
Robotics modem, you can get all the Internet
you want from any service provider who offers
the ITU 56K standard or x2™ technology.
This modem allows the greatest compatibility
for high speed downloads from service
providers that offer the ITU 56K standard
technology or x2 technology to their
customers. 3Com is working with providers
everywhere to quickly upgrade their service to
the ITU 56K standard.
*In accordance with the ITU-T standard for 56K
transmissions, this modem is capable of 56 Kbps
downloads. However, due to FCC rules which
restrict power output of the service providers’
modems, current download speeds are limited to 53
Kbps. Actual speeds may vary depending on line
conditions and other factors. Uploads from users
to server equipment travel at speeds up to 31.2
Kbps. An analog phone line compatible with the
ITU-T 56K standard or x2technology, and an
Internet provider or corporate host site compatible
with the ITU-T 56K standard or x2 technology are
necessary for these high-speed downloads.

PRODUCT FEATURES
2
Modulation Schemes
56K ITU-T standard
x2™ technology
ITU-T V.34+
ITU-T V.34
ITU-T V.32bis
ITU-T V.32
ITU-T V.22bis
ITU-T V.22
ITU-T V.23
Bell 212A
ITU-T V.21
Bell 103
Error Control and Data
Compression Schemes
ITU-T V.42
ITU-T V.42bis
MNP 2-5
Fax Modulation Schemes
ITU-T V.17
ITU-T V.29
ITU-T V.27ter
ITU-T V.21
Fax Standards
EIA 578 Class 1 FAX
EIA 592 Class 2.0 FAX
Front Channel Link Rates
28000, 29333, 30666, 32000,
33333, 34666, 36000, 37333,
38666, 40000, 41333, 42666,
44000, 45333, 46666, 48000,
49333, 50666, 52000, 53333,
54666, 56000, 57333
Back Channel Link Rates
4800, 7200, 9600, 12000, 14400,
16800, 19200, 21600, 24000,
26400, 28800, 31200
33600
V.34+ Link Rates
4800, 7200, 9600, 12000, 14400,
16800, 19200, 21600, 24000,
26400, 28800, 31200, 33600
V.32bis Link Rates
4800, 7200, 9600, 12000, 14400
Additional Link Rates
300, 1200/75 (V.23), 1200, 2400
Fax Link Rates
2400, 4800, 7200, 9600,
12000, 14400

BEFORE YOU BEGIN (WINDOWS®95 USERS)
3
Determining Available
Resources
Your U.S. Robotics®Voice modem is a Plug
and Play device. Windows®95 can
automatically identify a Plug and Play device
and determine if your system has the resources
necessary to support the device. However,
Plug and Play will not work if you do not have
resources available or if devices on your
system are not reporting resource usage
correctly. Here’s how you can verify that your
system has the necessary resources before
installing the modem:
1. Click the Windows 95 Start button, point
to Settings, and then click Control Panel.
2. Double-click the System icon.
3. When the “System Properties” screen
appears, click the Device Manager tab.
4. Double-click Computer and the
“Computer Properties” screen appears.
5. Select the option at the top of the screen to
show Interrupt Requests (IRQs).
You will see the IRQs your system is currently
using. If IRQs 3, 4, 5, and 7 are being used,
you need to free an IRQ before you begin
installation. This process involves moving a
device from the IRQ you want to use to a
different (and usually higher) IRQ setting.
Please read the documentation for (or contact
the manufacturer of) the device that is currently
using the IRQ you want to use for your modem
to learn more about how to free the IRQ for
your modem.

BEFOREYOUBEGIN(WINDOWS95 USERS)
4
Determining Your Version of
Windows 95
Follow these steps to determine your version
of Windows 95. This information will be
important during installation.
1. Click the My Computer icon on your
desktop with the right mouse button.
2. Click Properties.
3. In the “System Properties” screen, look at
the system information under the General
tab (circled in the following screen image).
The number following the text “Microsoft
Windows 95” will end with “950”, “950a”,
or “950b”. This indicates your version of
Windows 95. Write this number on the
blank below for later reference. Then click
OK.
Windows 95 version _________________

INTERNAL MODEM INSTALLATION WITH WINDOWS®
3.X
5
You will need these items from your
U.S. Robotics®modem box:
modem phone cord
Connections™CD microphone
Plus:
screwdriver (not included)
A Word about COM Ports and
IRQs
Most computer accessories — mouse, sound
card, enhanced graphics card, scanner, etc. —
require a special connection through which
they can communicate with the computer. For
some devices, this connection is called a
communications (or COM) port. Most
computers have 1 or 2 COM ports, though
they can have up to 4. Although internal
modems do not connect to COM ports
directly, they do require a COM port setting,
which is determined by the setting on the
modem’s COM jumper pins.

INTERNALMODEMINSTALLATIONWITHWINDOWS3.X
6
Each COM port uses an interrupt request
(IRQ). An accessory uses an IRQ to get the
attention of your computer’s centralprocessing
unit (CPU) so that the accessory can perform
a task. The computer stops what it’s doing,
depending on the priority of the request, to
help the accessory perform its task. When two
accessories share an IRQ, it’s like two people
asking different questions in unison to a third
person. Just as the person being asked the two
questions cannot understand either request, a
computer can lock up or otherwise fail to
communicate properly with your modem when
there is an IRQ conflict.
KEY POINT: Accessories cannot
share COM ports and should not share
IRQs. When accessories try to share
settings, they will either not work
properly or not work at all.
3Com has set your modem to a default Plug
and Play setting which is ideal for Windows 95
users. In this configuration, the shunts used to
set your modem’s COM port and IRQ settings
are hanging from single jumper pins and will
not affect your modem’s settings. As a
Windows 3.x user, you need to run the
ComTest program (on the ConnectionsCD)
to determine what settings your modem should
use.

INTERNALMODEMINSTALLATIONWITHWINDOWS3.X
7
NOTE: Somecommunications
softwareprogramsrequireaparticular
settingforyourmodem(theRapidComm
software,whichshippedwithyourmodem,
doesnot).Ifyouwishtouseaprogram
otherthanRapidComm,nowisagoodtime
toreadthatsoftware’smanualto
determinewhatsettingisrequired.
How to Use ComTest to Determine Your
Modem’s Settings
1. Insert the Connections CD into your CD-
ROM drive.
2. In Windows’ Program Manager,click File
and then click Run. Type d:\comtest.exe
and press ENTER. This starts ComTest, the
program that determines which COM ports
and IRQs are available for use by your
modem.
3. The screen in the next column appears when
ComTest starts.
• If there is a modem in your computer
which you are replacing with your new
U.S. Robotics modem, go to “Testing an
Installed Modem” on page 9 to
determine which COM and IRQ settings
the older modem is using.
• If a modem is not currently installed in
your computer, click Recommend
settings for a new modem. Then click
Next.

INTERNALMODEMINSTALLATIONWITHWINDOWS3.X
8
4. Click Internal Modem. Then click Next.
5. If you have a free setting, you will see a
screen like this.
(COM2/IRQ3 is free in this example.)
Write down the displayed settings here:
COM Port_________ IRQ_________
You will need to know these settings later.
Click Next.
If you do not have a free setting, you will
see a screen like the follwoing. Click Finish
to exit ComTest. Go to “What to Do with
ComTest’s Recommendation” on page 10.

INTERNALMODEMINSTALLATIONWITHWINDOWS3.X
9
6. When you see this screen, click Finish to
exit ComTest.
If ComTest recommended COM 1/IRQ 4
or COM 2/IRQ 3, turn to “How to Change
the Modem’s Settings” on page 12.
Otherwise, go to “What to Do with
ComTest’s Recommendation” on page 10.
Testing an Installed Modem
If there is a modem already installed in your
computer, you can determine its COM and
IRQ settings by selecting the Test an
installed modem option. Follow the
instructions on screen until you see the screen
that tells you “Testing is complete.” This screen
will also tell you which COM and IRQ settings
your present modem is using. These are the
settings you want to use for your new U.S.
Robotics modem. Write down the displayed
settings here:
COM Port_________ IRQ_________
Turn off and unplug your computer and
remove your present modem using its
documentation as a guide. Go to “How to
Change the Modem’s Settings” on page 12.

INTERNALMODEMINSTALLATIONWITHWINDOWS3.X
10
What to Do with ComTest’s
Recommendation
NOTE: If your communications
software requires a modem setting that
ComTest does not recommend, there is
a good chance that the setting is being
used by another device in your system.
To free that setting in your system,
consult your computer’s manual. Go to
“How to Change the Modem’s Settings”
on page 12.
If ComTest recommended COM3/IRQ4
or COM4/IRQ3
Do not use either of these settings. While the
COM port part of the setting is acceptable
(ComTest only recommends COM ports that
are not being used), the IRQ part of the setting
is not acceptable. When ComTest
recommends either COM3/IRQ4 or
COM4/IRQ3, the IRQ in the setting is being
used by another accessory. You could use the
suggested IRQ for the modem, but you run the
risk that the modem and/or the other accessory
sharing the IRQ might not work properly.
If you do not have a sound card, use
COM3/IRQ5. Write “COM3” and “IRQ5”
where it will be convenient during the
software installation. You will have to change
the settings on your modem. Go to “How to
Change the Modem’s Settings” on page 12.
If you do have a sound card, use
COM2/IRQ3. To use this setting, you have to
first disable your computer’s second serial port
(COM2). This is a pronged socket on the
back of your computer.
• Go to your computer manufacturer’s
manual.

INTERNALMODEMINSTALLATIONWITHWINDOWS3.X
11
• Find out how to disable the COM port.
• Find out which of the sockets on the back
of your computer COM 2.
• If you have something plugged into that
port, find out if you can plug it in
somewhere else. Any accessory plugged
into that port will not work after the port
has been disabled.
• Then return to this point in this manual to
continue.
After disabling COM2, you can use the
COM2/IRQ3 setting.
Write “COM2” and “IRQ3” where it will be
convenient during the software installation and
go to “How to Change the Modem’s Settings”
on page 12.
If ComTest reports that “You do not
have any available COM ports and/or
IRQs”
We recommend you disable COM1 or
COM2. When you disable one of these COM
ports, you can use it and its default IRQ for
your modem. Go to your computer
manufacturer’s manual.
• Find out which socket is COM1 and which
is COM2.
• If nothing is plugged into either port, you
may choose either of the ports to disable.
Your computer manufacturer’s manual will
tell you how to disable the COM port.
• If one port does not have anything plugged
into it, note if the port is COM1 or COM2.
This is the port you’ll want to disable for
your modem.
• If both ports are being used, you may be
able to attach one of the plugged-in

INTERNALMODEMINSTALLATIONWITHWINDOWS3.X
12
accessories elsewhere so that you can
disable its COM port. The accessory will
not work once its port is disabled.
If you’ve disabled COM1, you can now use
the COM1/IRQ4 setting. Write this setting
down where it will be convenient during the
software installation.
If you’ve disabled COM2, you can now use
the COM2/IRQ3 setting. Write the setting
down where it will be convenient during the
software installation. Go to “How to Change
the Modem’s Settings” (on this page).
How to Change the Modem’s
Settings
1. Always touch an unpainted metal part of
your computer (the back is usually
unpainted) to discharge static electricity
before handling the modem. Static can
damage your modem. Then take the
modem out of its plastic bag.
2. Find the COM and IRQ jumper shunts
(small black plastic pieces) on your
modem’s jumper pins (see the following
diagram).
3. To change the COM port and IRQ settings,
you need to reposition the jumper shunts on
the COM port and IRQ pins. To do this, lift
the jumper shunts off the pins.

INTERNALMODEMINSTALLATIONWITHWINDOWS3.X
13
TIP: Grasp the jumper shunts with
a tweezers or needle-nosed pliers. DO
NOT grasp too firmly, as you may crush
the jumper shunts. If a jumper shunt
seems stuck, gently rock it back and
forth as you lift. Do not touch any other
part of the modem or your computer
with the tweezers/pliers. A jumper
shunt needs to be sitting on both
jumper pins in order to effectively set
the modem to the desired setting.
4. Move the jumper shunt to the new setting.
• The COM port setting can involve one
to three shunts. The four possible COM
port settings are as follows:
0 1 SEL
COM 1
0 1 SEL
COM 3
0 1 SEL
COM4
0 1 SEL
COM2
• Unlike most COM port settings, the
IRQ setting involves only one jumper
shunt. Simply move the jumper shunt to
the pins labeled with the IRQ you need.

INTERNALMODEMINSTALLATIONWITHWINDOWS3.X
14
How to Insert the Modem into
the Computer
NOTE: Before installing your
modem, write its serial number in the
space provided here:
SERIAL
NUMBER:_____________
You will find the serial number
underneath the bar code on the white
sticker on the modem and on the
outside of the box the modem came in.
If you ever need to call our customer
support department, a customer
support representative will ask you
for the serial number. This will help
him or her identify your modem.
1. Turn off your computer and unplug it from
the electrical outlet.
2. Unplug any peripheral devices (printer,
monitor, keyboard, mouse, etc.) from the
computer.
TIP:Before you unplug anything,
label the cords or make a sketch of how
things are connected. This can be
helpful when you plug things back in
later.
CAUTION:To avoid the risk of
electric shock, make sure your computer
and all peripheral devices are turned off
and unplugged.

INTERNALMODEMINSTALLATIONWITHWINDOWS3.X
15
3. Remove the screws from your computer’s
cover and then remove the cover, as shown
in the following diagrams. Your computer
may differ in appearance from these
diagrams, but the basic principle for
removing the cover should be the same.
Contact your computer manufacturer or
review their manual if you need further
instructions.
4. Find an empty ISA expansion slot at least
as long as the gold edge of your modem.
(ISA slots are usually black plastic grooves
lined with silver metal.) Unscrew and
remove the expansion slot cover (the long
narrow piece of metal that keeps dust from
entering through the opening perpendicular
to the slot). Be careful not to drop the
screw into the computer. You will need it
later to screw the modem into place.

INTERNALMODEMINSTALLATIONWITHWINDOWS3.X
16
5. Holding the modem at each corner, with the
gold edge facing the slot, push the modem
down as gently as possible until it snaps into
the expansion slot. (The drawings show
horizontally aligned expansion slots. Some
computers have vertically aligned slots. The
instructions apply to both styles.)
You need to apply a little pressure to seat
the modem properly. Sometimes a gentle
back-and-forth motion helps to fit the
modem all the way into the slot. If you feel
resistance, the modem may not be properly
lined up with the slot. Do not force it into
the slot. Remove the modem and try again.
6. Once the modem is in the slot, fasten it
firmly into place using the screw that you
removed in step 4.
7. Replace the computer’s cover and fasten it
with the screws you removed in step 3.
8. If you currently have a phone plugged into
the wall jack you plan to use for the
modem, disconnect the phone’s cord from
the jack.