3Com TMX 10031161 User Manual

U.S. Robotics® Cable
Modem TMX
Getting Started Guide

http://www.3com.com/

Part No. 10031161
Published February 2000

3Com Corporation
3800 Golf Rd.
Rolling Meadows, IL
60008

Copyright © 2000 3Com Corporation. All rights reserved. No part of this documentation may be
reproduced in any form or by any means or used to make any derivative work (such as translation,
transformation, or adaptation) without written permission from 3Com Corporation.

3Com Corporation reserves the right to revise this documentation and to make changes in content
from time to time without obligation on the part of 3Com Corporation to provide notification of such
revision or change.

3Com Corporation provides this documentation without warranty of any kind, either express or
implied, including, but not limited to, the implied warranties of merchantability and fitness for a
particular purpose. 3Com may make improvements or changes in the product(s) and/or the program(s)
described in this documentation at any time.

If there is any software on removable media described in this documentation, it is furnished under a
license agreement included with the product as a separate document, in the hard copy documentation,
or on the removable media in a directory file named LICENSE.TXT or !LICENSE.TXT. If you are unable to
locate a copy, please contact 3Com and a copy will be provided to you.

UNITED STATES GOVERNMENT LEGEND

If you are a United States government agency, then this documentation and the software described
herein are provided to you subject to the following:

All technical data and computer software are commercial in nature and developed solely at private
expense. Software is delivered as “Commercial Computer Software” as defined in DFARS

252.227-7014 (June 1995) or as a “commercial item” as defined in FA R2.101(a) and as such is
provided with only such rights as are provided in 3Com’s standard commercial license for the Software.
Technical data is provided with limited rights only as provided in DFAR 252.227-7015 (Nov 1995) or FAR

52.227-14 (June 1987), whichever is applicable. You agree not to remove or deface any portion of any
legend provided on any licensed program or documentation contained in, or delivered to you in
conjunction with, this User Guide.

3Com, the 3Com logo, and U.S. Roboticsare registered trademarks and Connections is a trademark of
3Com Corporation.

Microsoft, Windows, and Windows NT are registered trademarks of Microsof tCorporation.

All other company and product names may be trademarks of the respective companies with which they
are associated.

C

ONTENTS

EFORE YOU BEGIN

B

1

Introduction 1
Cable Modem TMX Features 1
Contacting Your Broadband Service Provider (BSP) 2
Preparing Your Workspace 3
You Will Need These Items 4
Configuring the TCP/IP Protoco l5

Configuring the TCP/IP Protocol on a Windows P C5
Configuring the TCP/IP Protocol on a Macintosh P C7

ARDWARE INSTALLATION

H

2

Wall-Mount Installation 11
Desktop Installation 13
Stacking Installation with OfficeConnect Products 14
Connecting the Cable Modem to Your Computer 15

ABLE MODEM CONFIGURATION

C

3

Configuring Non-3Com U.S. Robotics Modems for Use with the
TMX 22

Using the Cable Modem TMX 24
Summary of Configuration Software Screens24

Dial/HangUp 25
Rescan Channels 25
Tune Frequency 26
DHCP Configuration 26
Enroll 27
Dial-Up Parameters 28

Dialing Parameters 29
Access Parameters30

DHCP/PPP Parameters 31
Cable Modem Configuration 32
Session Status 33

Message Log 33
Interpreting Your Cable Modem's LED Lights 34
Upgrading to CMX Functionality 35

ROUBLESHOOTING AND SUPPORT RESOURCES

T

4

Troubleshooting 37

The analog modem does not dial my cable company’s server

properly. 37

My computer went into “power save” mode. When it came

out of power save mode, my screen was frozen. 37

I see a delay when loading Web pages or downloading files

(Mac users only). 38

I cannot access the 149.112.50.65 URL after disconnecting

from my BSP .38

The Cable Status LED never stops blinking. 38
Support Resources 38

If You Are Still Having Problems 38

If You Need to Return the Modem to Us 39

World Wide Web 39

90-Day Free Installation Support 39

Technical Support Hotline 39

EGULATORY INFORMATION AND LIMITED WARRANTY

R

5

Manufacturer’s Declaration of Conformity 41

Caution to the User 41

Performance Specifications 41

Export Notices 41

License Agreement 42

Industry Canada (IC) 42

UL Listing/CUL Listing42

Radio and Television Interference 42
3Com Corporation Limited Warranty 43

Hardware 43

Software 44

Year 2000 Warranty 45

Obtaining Warranty Service 45

WARRANTIES EXCLUSIVE 46

LIMITATION OF LIABILITY 47

Disclaimer 47

Governing Law 47

ALL-MOUNTING TEMPLATE

W

6

1

Introduction

This guide provides all the information you need to use
your Cable Modem TMX and an analog modem to dial into
one-way Broadband Service Providers (BSPs).

Not all cable companies and BSPs provide two-way service.
In the event that you have a one-way cable provider or BSP,
you need to use an analog modem to send data to the
provider, and then receive data from the provider over the
cable line using a cable modem like the TMX.

BSPs who currently offer one-way service may choose to
upgrade to two-way service at some point in the future.
Your new Cable Modem TMX is software upgradable to
the full operation of the 3Com
Modem CMX. See the chapter in this guide about two-way
access for more information.

If you purchased the TMX Dialup Kit, the external analog
modem required for dialing into your provider is included.
If you purchased the TMX modem alone, you will need a
compatible external serial analog modem. (This product
will not work with an internal or USB-only analog modem.)
The diagrams and instructions in this guide assume you
have purchased the Dialup Kit.

B

EFORE YOU BEGIN

®

U.S. Robotics® Cable

Installation using a modem other than the one included in
the Dialup Kit should be very similar to the procedures
described in this guide. Consult your analog modem's
documentation for more details concerning its operation
and setup.

Cable Modem TMX Features

■

Downstream user data rates of up to 38 Mbps
(megabits per second), faster than 56K analog
modems, ISDN, or ADSL

2

HAPTER

■

EFORE YOU BEGIN

Plug and play operation ensures easy setup and

1: B

C

installation

■

3Com’s extensive user support organizations and our

5-year limited warranty

* Please note that the following factors affect the

speeds you may experience:

■

Your computer equipment and configuration,
including the speed of your processor, the amount
of RAM on your system, and your available hard disk
space.

■

The Internet browsing, e-mail, or other programs
you run at the same time, which use your
computer’s resources.

■

The capacity of the Internet service you order from
your provider.

■

Changing network traffic levels depending on when
you go online.

Contacting Your Broadband Service Provider (BSP)

In order to use your cable modem, you need to establish an
Internet access account with your local BSP. Before
contacting your BSP to establish an account, have the
following information handy:

■

The modem’s Media Access Control (MAC) address

(located on a bar code sticker on the back of the

modem). The MAC address consists of 12 characters

preceded by the text EA =. In the following example

label image, the

MAC address is 00104B377410. Write the MAC

address in the blank provided below.

Preparing Your Workspace

■

The modem’s model number (located on a sticker on

3

the bottom of the modem).

MAC address: EA = __________________
Model number: 3CR292B-TR56

You should now contact your BSP and verify the following:

■

You have cable service to your home that supports
cable modem access. If your BSP does not provide

cable modem access, the 3Com U.S. Robotics Cable
Modem TMX will not be able to communicate with your
BSP’s Internet access service. Visit the following URL for
additional information:

http://www.3com.com/cablemodem

■

Your BSP has set up your cable Internet access
account. Your BSP will establish an Internet access

account that will allow you to send and receive e-mail,
access the World Wide Web, and receive other Internet
services. This account must be established before you
can use your cable modem.

■

You have a cable line near your PC and it has been
prepared for cable modem service. If you do not

have a cable line in your home that supports cable
modem access or if your current cable connection is not
conveniently located near your computer, your cable
company can install one. If you use your cable line for
cable television access, your cable company can also
install an additional line for use with your cable modem.

Preparing Your Workspace

■

Position your computer so that it is located near your
cable outlet.

■

The cable modem should be located near your
computer and the cable outlet. There should be plenty
of room to guide the cables away from the modem
without crimping the cables.

■

The modem should be located where it has ample space
to allow constant airflow around the unit.

4

HAPTER

■

EFORE YOU BEGIN

Do not stack anything on top of the cable modem. (See

1: B

C

the instructions on page 14 concerning stacking this

modem with 3Com OfficeConnect products.)

■

The temperature in the room where the cable modem

will be operating should be between 0 and 40°C (32

and 104°F). Relative humidity should be between 5 and

95%, non-condensing.

■

Familiarize yourself with all of the materials in this box.

Please read these installation instructions thoroughly

before installing your cable modem.

CAUTION: Your cable company will provide a cable
connection. Do not attempt any rewiring without first
contacting your cable company.

You Will Need These Items

Included:

■

Cable modem

■

Cable modem power supply

■

Analog modem, power supply, and DB-25 to DB-9 cable

(TMX Dialup Kit only)

■

RJ-45 network cable

■

Rubber feet and stacking clips kit

■

This Getting Started Guide

Not Included:

■

A PC running Windows 95 operating system (or later)

or a Macintosh



computer running the System 7.5
operating system (or later) with TCP/IP protocol installed
(see the following two sections for more information on
installing TCP/IP)

■

An active cable line

■

An active Ethernet port or network interface card (NIC)
installed in your computer

■

A 7/16 inch (or adjustable) wrench for securing the
cable line to the modem

■

A screwdriver, pushpins, and screws (for optional
wall-mounting) The screw heads should be at least 0.2”
(5mm) in diameter for them to be properly captured in

Configuring the TCP/IP Protocol

the slot. If you are using wood screws, use #6 pan
heads or equivalent.

Configuring the TCP/IP Protocol

NOTE: If you are using a Macintosh computer, turn to the
instructions on page 7.

Configuring the TCP/IP Protocol on a Windows PC

You need to make sure that either an active Ethernet port,
Ethernet Network Interface Card (NIC), or an active USB
port and the TCP/IP communications protocol are installed
on your system before you install your cable modem.
Configure TCP/IP as described in the following set of
instructions.

1 Right-click the Network Neighborhood icon on your

desktop and then click Properties.

2 A list of installed network components appears. Look for

an entry named “TCP/IP”. This entry may be followed by an
arrow and a description of the NIC hardware device or USB
network interface installed in your computer. If an entry
similar to this is present, go to step 9.

.

5

3 If a similar entry is not present, click Add...

4 Click Protocol, and then click Add...

5 Click Microsoft in the "Manufacturers:" list and then click

TCP/IP in the "Network Protocols:" list. Click OK.

6

HAPTER

EFORE YOU BEGIN

1: B

C

6 "TCP/IP" will appear in the list of installed network

components. Click OK.

7 Windows will now ask you if you would like to restart your

computer. Click No.

8 Right-click on the Network Neighborhood icon on your

desktop then click Properties in the drop-down menu that
appears.

9 Double-click the entry in the "Configuration" menu that

reads "TCP/IP -->" followed by a description of your NIC or
dialup adapter.

10 Click the “Advanced” tab and then make sure the box next

to "Set this protocol to be the default protocol." is
checked. If it is not, click the box to put a check in it. (If this
option is grayed out, then you do not have TCP/IP installed
properly.)

11 Click OK and then click OK again.

12 Click the Windows Start button and then click Run.

13 When the “Run” screen appears, type winipcfg in the text

field and click the OK button.

14 The "IP Configuration" window will appear. Click the

Release button. A line of zeros will appear in the "IP

Address" and "Subnet Mask" fields.

Configuring the TCP/IP Protocol

15 Click the Renew button. Numbers will replace the zeros.

Click OK and turn to "Hardware and Software Installation"
(page 11).

NOTE: The numbers on your screen SHOULD be different
than those shown in the following example.

Configuring the TCP/IP Protocol on a Macintosh PC

You need to make sure that the TCP/IP communications
protocol is installed on your system before you install your
cable modem.

7

1 Click the Apple icon in the upper left corner of the Finder.

Scroll down to Control Panels, and click TCP/IP.

8

HAPTER

EFORE YOU BEGIN

1: B

C

2 Click Edit on the Finder (gray bar) at the top of the screen.

Scroll down to the bottom of the menu and click User

Mode.

3 Click the Advanced button then click OK.

4 Click the Up/Down selector arrows (to the right of

“Connect Via”) and click "Using DHCP Server".

5 Click the Options button. Then click the Active button.

NOTE: In some cases, the Load only when needed
button will not appear. If it is visible, click the box. A check
mark should appear in the box.

Configuring the TCP/IP Protocol

9

6 Verify that the “Use 802.3” box is unchecked (circled in the

following image). If there is a check mark in the box, click it
to remove the check mark. Then click the Info button in
the lower left corner.

7 Ensure there is a Hardware Address listed in this window. If

there is, click the OK button and close the “TCP/IP Control
Panel” (click File and scroll down to click Close). If there is
no Hardware Address, you must shut down and power off
your computer. With the power off, simultaneously depress
and hold down the Command (Apple), Option, P, and R
keys on your keyboard. Keeping those keys depressed,
power on the Macintosh computer. The machine will start
and you will hear the Apple chime. Keep these keys
depressed for up to 3 chimes, then release the keys and
allow the computer to start-up. When fully rebooted,
ensure that all TCP/IP settings match those in the preceding
instructions. If your computer still does not have a

10

1: B

C

HAPTER

EFORE YOU BEGIN

Hardware Address, please contact your local Apple
authorized dealer or Apple support.

2

H

ARDWARE INSTALLATION

NOTE: Before installing your modem, write its serial
number in the space provided on the first page of this
manual. (You’ll find the serial number above the bar code
on the white sticker on the back of the modem and on the
outside of the modem’s box.) If you ever call our customer
support department, a representative will ask you for the
serial number. This will help to identify your modem.

Before you begin installing the cable modem hardware,
you need to determine how you want to incorporate the
modem into your work environment. There are three
installation options:

■

Wall-mount installation (this page)

■

Desktop installation (page 13)

■

Stacking installation with OfficeConnect products (page

14)

Wall-Mount Installation

Your cable modem is capable of being wall-mounted, if
you choose to do so. The bottom panel of the cable
modem has two raised brackets with slots as shown in the
following illustration.

NOTE: Before wall-mounting the cable modem, follow the
instructions in the section “Connecting the Cable Modem
to Your Computer” (pages 15-19). Then return to this point
to continue the process.

12

2: H

C

HAPTER

ARDWARE INSTALLATION

mounting

holes

These slots fit over the heads of wall-mounting screws to
secure the modem to the wall.

1 Remove the mounting template from this Guide.

2 Place the mounting template against the wall at the

location chosen for the cable modem. The template should
be parallel to and at least 20 inches (50 cm) from the floor.
Insert pushpins through the template cross hairs into the
wall to mark the locations for the screws.

®

3 Secure the mounting screws into the wall. Do not drive the

screws flush to the wall. The screw head should be at least
¼” (6 mm) away from the wall so it can lock into the slots
on the modem’s case.

4 Fit the slots in the brackets on the modem’s underside over

the screw heads and let the modem slide down into
position.

T

C

U

R

T

S

m

IN

e

T

g

in

t

b

n

r

u

o

f

o

e

m

-

d

l

i

l

s

u

a

r

r

t

W

e

s

h

t

in

o

e

t

e

e

e

l

p

S

m

o

c

r

o

F

20"

[ 50 cm ]

Desktop Installation

M

E

D

O

M

E

L

B

A

C

E

H

T

G

IN

T

N

U

O

-M

L

L

A

W

.

e

R

c

n

O

e

r

F

e

f

S

e

R

N

&

IO

e

id

.

u

s

G

n

o

i

's

t

e

r

t

c

e

a

u

l

s

r

t

p

U

s

e

in

h

t

c

i

s

e

a

e

s

,

s

n

io

t

c

®

13

If you have not already done so, turn to “Connecting the
Cable Modem to Your Computer” (page 15) to complete
your installation.

Desktop Installation

If you plan to place your modem on a flat surface, you can
use the four self-adhesive rubber feet included in your
modem’s package to prevent your modem from sliding
around. Stick the feet to the marked areas at each corner
of the underside of your modem. Turn to “Connecting the
Cable Modem to Your Computer” (page 15).

2: H

14

C

HAPTER

ARDWARE INSTALLATION

Stacking Installation with OfficeConnect Products

If you own 3Com OfficeConnect products, you can use the
four stacking clips included in your modem’s package to
neatly and securely stack your cable modem with the
OfficeConnect unit(s). If possible, your cable modem
should always be the top unit in a stack with OfficeConnect
products. Small hubs are the only units that should be
clipped to the top of a cable modem. Follow these
instructions to clip your modem to an OfficeConnect unit.

1 Place the OfficeConnect device you want at the bottom of

the stack on a flat surface. The supplied blue clips fit in the
positions on the side of the unit as shown in step 1 of the
illustration on the next page.

2 Position a clip over one of these holes and push it in until it

clicks into place, as shown in step 2 of the illustration on
the next page. Repeat this for the other clip position on the
same side.

3 Keeping the front of the units aligned, position the

top-most OfficeConnect device and rest the bottom of the
device on the clips' spikes, as shown in step 3 of the
illustration on the next page. Push the clips firmly until they
click into place.

NOTE: To remove a clip, hold the units firmly with one hand
and hook the first finger of your other hand around the
back of the clip. Be careful not to pull so hard that you
break the clip.

4 Repeat these steps to secure the other side.

5 Turn to “Connecting the Cable Modem to Your Computer”

(page 15).

Connecting the Cable Modem to Your Computer

15

Connecting the Cable Modem to Your Computer

TIP: Before you unplug any cords, label them or make a
sketch of how they are connected. This can be helpful
when you plug them back in later.

CAUTION: To avoid risk of electric shock, make sure your
computer and all peripheral devices are turned off and
unplugged from electrical outlets.

NOTE: Refer to the diagram on the following page while
following these steps.

1 Turn off your computer and unplug it from the electrical

outlet.

2 Using the following illustrations as a guide, make the

following connections:

16

C

HAPTER

2: H

ARDWARE INSTALLATION

■

Connect your cable line to the cable modem’s CATV
cable connector. Be careful not to bend the wire in
the center of the cable line when you connect it to
the cable modem. After hand-tightening the CATV
cable connector, use your 7/16 inch or adjustable
wrench to firmly tighten the connector. Be careful
not to over-tighten the connector or you might
damage the connector or your cable modem.

■

Plug the cable modem’s power supply into a wall
socket or surge protector and into the cable
modem’s power jack (labeled with a graphic that
looks like this:

■

Plug one end of the RJ-45 network cable into the

+

-

).

cable modem’s RJ-45 jack and the other end into the
existing network interface card installed in your
computer.

10 BT

SERIAL

CATV

cable line (to cable
outlet)

■

Plug the included RS-232 connector cable to the

RJ-45 cable

RJ-45 Cable

(to NIC)

serial port on your cable modem and to the serial
port on your analog modem.

■

Plug the analog modem’s power supply into the
modem and into a wall socket or surge protector.

power supply
(to wall outlet)

Connecting the Cable Modem to Your Computer

Com

to an electrical

outlet
to an analog
phone jack

to a telephone

to serial jack on
the cable modem

■

Plug a phone cord into the analog modem’s TELCO
jack (marked with a on the bottom of the
modem’s case) and a wall phone jack. If you
purchased the TMX Dialup Kit, use the phone cord
included with the analog modem. If you would like
to use a phone on the same wall jack you intend to
use with the analog modem, plug your phone’s cord
into the jack marked with a on the bottom of the
modem’s case. When you are finished making all of
the necessary connections, your setup should
resemble the following diagram.

17

power supply cable
(to wall outlet)

RJ-45 cable
(to NIC)

U.S. Robotics

phone outlet

cable outlet

RS-232 cable

3

2

1
2
1

31

1

41

0

59

68
7

5

5
1

2

5

0

8

3

0
8

5
4

5
7

0

5

0
7

5

5

5

0

6

6

s

c

i

t

o

b

o

R

.

S

X

.

M

C

U

m

m

e

o

d

3

C

o

M

e

l
b
a

C

Cable

power supply cable
(to wall outlet)

PCLink

Cable

FCN

Modem

Activity

Activity

Status

Status

Power

3 Turn the analog modem on. The power switch is located on

the top front of the modem’s case.

4 Turn your computer on. You are now ready to configure

your Cable Modem TMX using our Web-based
configuration software. See the next chapter for details.

18

C

HAPTER

2: H

ARDWARE INSTALLATION

C

ABLE

M

ODEM

3

1 Open your Web browser and click on your home or

2 The “Configuration Screens” menu is the first that

C

ONFIGURATION

The first time you use your Cable Modem TMX, you must
configure it using our Web-based configuration software.

NOTE: If you do not currently have a Web browser installed
on your computer, you can find the two most popular
browsers, Netscape Navigator and Microsoft’s Internet
Explorer, on the Cable Connections
with your kit.

start-up page, which you should have set as the following
URL in the "Before You Begin" section of this manual:

http://149.112.50.65

appears. Click Enroll.

TM

CD-ROM included

3 On the "Enroll" screen, highlight your BSP in the

drop-down menu that appears and click Show.

20

C

HAPTER

3: C

ABLE MODEM CONFIGURATION

21

4 This brings up the “Dial-Up Parameters screen”. Click

Dialing Information.

5 Fill in the "Dialing Information" fields with the information

that should have been already provided to you by your BSP.
When you are finished entering the information, click

Submit.

22

C

HAPTER

3: C

ABLE MODEM CONFIGURATION

If you are using a 3Com U.S. Robotics external analog
modem in conjunction with your Cable Modem TMX, turn
to "Using the Cable Modem TMX" on page 24. Otherwise,
see the following section for information about configuring
non-3Com U.S. Robotics modems.

Configuring Non-3Com U.S. Robotics Modems for Use
with the TMX

The TMX cable modem is designed to work with a variety
of external V.34 modems. If you're using an external
modem other then a 3Com U.S. Robotics external modem,
please verify that your modem meets these minimum
requirements.

■

Modem must be AT command set addressable

■

Modem must support the V.34, V.34bis, or V.90
standard

Configuring Non-3Com U.S. Robotics Modems for Use with the TMX

■

Modem must have an RS-232 standard interface

■

Modem’s serial port rate must support 115.2 Kbps

■

Modem’s serial port must be configurable to support
hardware flow control

If your modem meets these minimum requirements, it may
be used with the TMX cable modem, but please remember
that the quality of your external analog modem directly
effects the performance of your cable connection.

In addition to meeting the basic requirements, your analog
modem may need to be configured to work properly with
the TMX cable modem. The included configuration
software provides a "Cable Modem Configuration" screen
which can be used to pass additional parameters to your
analog modem. These parameters are AT command strings
used during initialization. Since the parameters are often
manufacturer specific, list below is the optimal
configuration. The characters in brackets are the equivalent
3Com U.S. Robotics modem commands. Please refer to
your analog modem's user manual for the exact AT
commands. It is not necessary to enter AT into the
parameter field, only the command parameter.

23

■

Return result codes in words [V]

■

Serial port rate higher than connect rate [&B1]

■

Transmit data Hardware flow control [&H1]

■

Receive data Hardware flow control [&R2]

■

Auto enable V.42 Error correction [&M4]

■

Auto enable V.42bis data compression [&K1]

■

ITU-T (formerly CCITT) answer sequence [B0]

■

Carrier Detect follows connection (&C1)

For example, in order to program your analog modem as
described by these commands, you would enter the
following string into the "Use User Initial" field on the
"Cable Modem Configuration" screen:

V&B1&H1&R2&M4&K1B0&C1

Since the quality of analog modems and telephone lines
varies greatly, in most cases V.42 error correction and
V.42bis data compression should be used. In other

3: C

24

C

HAPTER

ABLE MODEM CONFIGURATION

situations, where the analog modem and telephone line
quality are both satisfactory, you can disable V.42 error
correction and V.42bis data compression. Disabling V.42
error correction and V.42bis data compression while using a
quality analog modem on a quality telephone line can
improve analog response time and thereby improve your
data throughput.

After you have configured your modem with these
parameters, you should be ready to connect to your cable
data service provider.

Using the Cable Modem TMX

You are now ready to point your browser at any site you
wish or launch your Internet software. As soon as you
initiate Web-based activity, the Cable Modem should dial
out to your BSP's server and establish your connection. This
should happen every time you start your computer now
that you have configured your TMX.

Some Internet applications may produce a “time out” error
while waiting for your connection to be established. This is
normal. Once you’ve established a connection, refresh or
restart your Internet software.

See page 34 for information about interpreting the LEDs on
the front of your TMX.

Summary of Configuration Software Screens

The following is a brief summary of the screens you can
access from the main menu and how they can help you
configure your cable modem and your connection.

Dial/HangUp

If you would like to hang up the current connection, you
can do so by accessing this menu and clicking HangUp
Phone. Once you are ready to establish a new connection,
click Dial Phone.

Summary of Configuration Software Screens

25

Rescan Channels

3: C

26

C

HAPTER

This menu allows you to manually start a scan for an open
channel by clicking the Scan Now button. This is useful if
for some reason the cable modem is not currently locked
on to an active signal.

Tune Frequency

ABLE MODEM CONFIGURATION

This screen allows you to tune the cable modem to an
exact frequency. Type the frequency you want to tune to in
the “Frequency (Hz)” box and then click Tune Now to set
the modem to that frequency.

DHCP Configuration

Enroll

Summary of Configuration Software Screens

27

This screen allows you to select options for
detecting/selecting source IP addresses for out-bound
DHCP packets. Choose your method of detection and then
click Submit.

Access this screen to enroll into a new cable modem access
account with a Broadband Service Provider (BSP).

3: C

28

C

HAPTER

ABLE MODEM CONFIGURATION

Dial-Up Parameters

This screen provides links to screens which allow you to
modify the dial-up parameters for your cable modem.
Here’s an overview of these screens.

Summary of Configuration Software Screens

Dialing Parameters

29

This screen allows you to enter primary and backup phone
numbers into which your analog modem can dial to access
your Broadband Service Provider’s (BSP’s) cable modem
service. Your BSP should provide you with numbers for
these fields.

30

3: C

C

HAPTER

ABLE MODEM CONFIGURATION

Access Parameters

This screen allows you to modify your account’s login
name, password, and radius realm information.

Summary of Configuration Software Screens

DHCP/PPP Parameters

31

Here you can view your curent provider information, select
authentication and server IP address, and set PPP
authentication to PAP only, CHAP only, or a negotiated
setting.

3: C

32

C

HAPTER

ABLE MODEM CONFIGURATION

Cable Modem Configuration

This screen displays information concerning your cable
modem’s configuration and allows you to edit your user
initial.

Session Status

Summary of Configuration Software Screens

33

This option displays information concerning your cable
modem’s current connection.

Message Log

3: C

Com

1

2

3

4

5

6

34

C

HAPTER

ABLE MODEM CONFIGURATION

The Message Log documents the events of each cale
modem session (establishing connections, failures to
connect, file transfers, etc.). In Internet Explorer, a new
window opens to capture activity reports and in Netscape
Navigator, the browser creates and saves an HTML file
containing the information. The information generatied by
the Message Log can be helpful if you need to troubleshoot
problems with our technical support staff.

Click Refresh to show the messages generated since the
last time the screen was accessed. Click Clear Log to
delete all existing messages. Click Start Log Capture to
open a new browser window that monitors generated
messages in real time. The Message Log will continue to
show generated messages until you click Stop Log
Capture. This option is helpful for analyzing a specific
period of time during a given connection when
troubleshooting problems.

Interpreting Your Cable Modem's LED Lights

Here’s a quick overview of the LED lights on the front panel
of your modem and what they can tell you about the
performance of your modem and the condition of your
connection.

s

c

i

t

o

b

o

R

.

S

X

.

M

C

U

m

m

e

o

d

3

C

o

M

e

l

b

a

C

Cable

PC Link

Power

Cable

Modem

Status

Status

Activity

Activity

FCN

1 Cable Modem Power - Indicates power is applied to the

cable modem. This light is solid green when the modem is
on.

2 Cable Modem Status - This LED varies in color (orange

and green) and indicates the modem’s status as described
in the following chart:

Upgrading to CMX Functionality

LED STATE REPEATING DESCRIPTION

SHORT OFF, LONG
ORANGE

ORANGE NO Failed power on self test

SHORT OFF, SHORT
ORANGE

LONG ORANGE, SHORT
GREEN

SHORT OFF, SHORT
GREEN

GREEN NO Fully operational state

YES Startup, power on self test

YES Downstream hunt

YES Acquisition in process

YES Offline/not authorized for service

3 PC Link Status - Indicates that the cable modem is

connected to the Ethernet card in your computer. This light
is solid green when this link is established and your
computer is on.

4 PC Link Activity - Indicates that data is being transmitted

to or from your PC over the Ethernet port. Flashing orange
indicates traffic. This LED should blink when data is being
transmitted or received over the Ethernet port.

35

Upgrading to CMX Functionality

If your BSP decides to upgrade their service to two-way
functionality, they may automatically upgrade your TMX to
CMX functionality. You will be alerted if this happens. In
this even, you will want to download our 3Com U.S.
Robotics Cable Modem CMX documentation at:

http://consumer.3com.com/cable

36

C

HAPTER

3: C

ABLE MODEM CONFIGURATION

T

ROUBLESHOOTING AND

4

S

UPPORT RESOURCES

Troubleshooting

The analog modem does not dial my cable company’s server
properly.

■

Make sure that the power supplies for both the analog
modem and the TMX are plugged into electrical outlets
and make sure the analog modem is turned on.

■

Make sure your phone line is active. Plug a telephone
into the analog phone jack and listen for a dial tone.

■

Make sure there are no devices between the analog
modem and the phone jack.

■

If you have voice mail, there may be messages waiting
for you, altering the dial tone. Answer any messages to
return the dial tone to normal.

■

Make sure you are dialing the correct access number for
your cable company’s cable modem service.

■

Make sure the telephone cord is plugged into the
analog modem you have connected to the TMX.

My computer went into “power save” mode. When it came
out of power save mode, my screen was frozen.

If the upstream (analog modem) connection is active when
a computer goes into power save mode, the computer may
freeze when coming out of power save mode. Either hang
up the analog modem before your computer goes into
power save mode or disable power save on your PC. If you
choose to disable power save, disable it in both the
Windows 95 Control Panel and the BIOS setup. To disable
power save in Windows 95, click Windows 95 Start, point
to Settings, and click Control Panel. Double-click the
Power icon and select OFF in the “Power Management”
box. Click Apply. To disable power save in the BIOS setup,
you usually must press a function key while booting up to

4: T

38

C

HAPTER

ROUBLESHOOTING AND SUPPORT RESOURCES

enter the setup menu. Consult you computer’s manual for
exact instructions.

I see a delay when loading Web pages or downloading files
(Mac users only).

■

Close your Internet software and restart it.

■

If you are attempting to access a Web page, refresh or
reload the page you are trying to access in your
browser.

I cannot access the 149.112.50.65 URL after disconnecting
from my BSP.

You may need to renew your DHCP lease.

WINDOWS USERS: Click Start, click Run, type
winipcfg, and press ENTER. Select the NIC card that

your cable modem is plugged into in the drop down
menu that appears. Click Release and then click
Renew. Exit out of the "IP Configuration" window and
attempt to access the 149.112.50.65 URL again.

IMAC AND LINUX USERS: Restart your computer or
wait for your current DHCP lease to expire.

The Cable Status LED never stops blinking.

The signal from your cable company's equipment may be
too weak or the cable line may not be properly attached to
the modem. If the cable line is properly connected to the
modem, call your cable company to verify whether or not a
weak signal may be your problem.

Support Resources

If You Are Still Having Problems

■

Review this manual.

■

Call or visit your modem dealer. They may be able to
assist you.

■

If your dealer can't help you, contact 3Com Technical
Support. When you call, specify your modem's serial
number (found on the modem and on the outside of
the box) and the software being used.

If You Need to Return the Modem to Us

Contact 3Com Technical Support. If the support
representative determines that you need to return the
modem, you will receive a USO (User Service Order)
number. You must have a USO number before returning
the modem to us. Ship the unit, postage paid, in a strong
box made of corrugated cardboard with plenty of packing
material. DO NOT send the modem back in the original
box. Send ONLY the modem (NOT manuals, diskettes, CDs,
etc.). Include your USO number, name, and address on the
shipping label as well as inside the package. If possible,
send the package via a courier capable of tracking the
progress of the shipment. Ship to the following address:

3Com

USO #________

Dock 15

1800 W. Central Ave.

Mount Prospect, IL 60056

World Wide Web

To visit our online support home page, log on to:

http://consumer.3com.com/cable/

Support Resources

39

You can send a message to technical support by clicking

Contact Us in the “Site Tools” section of this Web site.

90-Day Free Installation Support

3Com offers free installation support for this product 90
days after purchase. Please call the following toll-free
number.

888-877-5040

After the 90-day period, refer to our regular Technical
Support Hotline (below).

Technical Support Hotline

Technical questions about 3Com cable modems can also be
answered by technical support representatives. Regular
telephone charges apply. The hours service is available are
7:00 AM - 11:00 PM CST seven days a week.

847-262-2550

40

C

HAPTER

4: T

ROUBLESHOOTING AND SUPPORT RESOURCES

R

EGULATORY INFORMATION

5

Manufacturer’s Declaration of Conformity

1 this device may not cause harmful electromagnetic

2 this device must accept any interference received including

Caution to the User

AND LIMITED

3Com
3800 Golf Road
Rolling Meadows, IL 60008
U.S.A.

declares that the product 3Com U.S. Robotics Cable

Modem TMX conforms to the FCC’s specifications:

Part 15

Operation is subject to the following two conditions:

interference, and

interference that may cause undesired operations.

The user is cautioned that any changes or modifications
not expressly approved by the party responsible for
compliance could void the user’s authority to operate the
equipment.

W

ARRANTY

Performance Specifications

This equipment has a bit-error rate (BER) less than 10-8
when the signal-to-noise ratio (SNR) is 23.5 dB or greater
when operating in 64 QAM mode, and when the SNR is

30.0 dB or greater when operating in 256 QAM mode.

Export Notices

■

Unlawful to export from the US or Canada without an
approved US Department of Commerce export license.

■

The hardware contained in this product contains
encryption software which may not be exported or

5: R

42

C

HAPTER

EGULATORY INFORMATION AND LIMITED WARRANTY

transferred from the US or Canada without an
approved US Department of Commerce export license.

License Agreement

You agree that you will not export or re-export the
Software or accompanying documentation (or any copies
thereof) or any products utilizing the Software or such
documentation in violation of any applicable laws or
regulations of the United States or the country in which
you obtained them.

The software covered by this agreement may contain
strong data encryption code that cannot be exported
outside of the U.S. or Canada. You agree that you will not
export/reexport, either physically or electronically, the
encryption software or accompanying documentation (or
copies thereof) or any products utilizing the encryption
software or such documentation without obtaining written
authorization from the U.S. Department of Commerce.

Industry Canada (IC)

This digital apparatus does not exceed the Class B limits for
radio noise emissions from digital apparatus set out in the
interference-causing equipment standard entitled Digital
Apparatus, ICES-003 of Industry Canada.

Cet appareil numérique respecte les limites de bruits
radioélectriques applicables aux appareils numériques de
Classe B préscrites dans la norme sur le matériel brouilleur:
Appareils Numériques, NMB-003 édictée par l'Industrie
Canada.

UL Listing/CUL Listing

This product is UL and CUL listed for the uses described in
this manual.

Radio and Television Interference

This equipment generates and uses radio frequency energy
and if not installed and used properly, in strict accordance
with the manufacturer’s instructions, may cause
interference to radio and television reception. This device
has been tested and found to comply with the limits for a
Class B computing device in accordance with the

3Com Corporation Limited Warranty

43

specifications in Part 15 of FCC rules, which are designed
to provide reasonable protection against such interference
in a residential installation.

However, there is no guarantee that interference will not
occur in a particular installation. If this device does cause
interference to radio or television reception, which you can
determine by monitoring reception when the modem is
installed and when it is removed from the computer, try to
correct the problem with one or more of the following
measures:

■

Reorient the receiving antenna (for televisions with
antenna reception only) or cable input device.

■

Relocate the computer with respect to the receiver.

■

Relocate the computer and/or the receiver so that they
are on separate branch circuits.

If necessary, consult your dealer or an experienced
radio/television technician for additional suggestions. You
may find the following booklet, prepared by the Federal
Communications Commission, helpful:

How to Identify and Resolve Radio-TV Interference
Problems

Stock No. 004-000-0345-4
U.S. Government Printing Office
Washington, DC 20402

In accordance with Part 15 of the FCC rules, the user is
cautioned that any changes or modifications to the
equipment described in this manual that are not expressly
approved by 3Com could void the user’s authority to
operate the equipment.

3Com Corporation Limited Warranty

Hardware

3Com warrants to the end user (“Customer”) that this
hardware product will be free from defects in workmanship
and materials, under normal use and service, for the
following length of time from the date of purchase from
3Com or its authorized reseller: 5 years.

44

Software

5: R

C

HAPTER

EGULATORY INFORMATION AND LIMITED WARRANTY

3Com’s sole obligation under this express warranty shall be,
at 3Com’s option and expense, to repair the defective
product or part, deliver to Customer an equivalent product
or part to replace the defective item, or if neither of the
two foregoing options is reasonably available, 3Com may,
in its sole discretion, refund to Customer the purchase price
paid for the defective product. All products that are
replaced will become the property of 3Com. Replacement
products may be new or reconditioned. 3Com warrants
any replaced or repaired product or part for ninety (90)
days from shipment, or the remainder of the initial
warranty period, whichever is longer.

3Com warrants to Customer that each software program
licensed from it will perform in substantial conformance to
its program specifications, for a period of ninety (90) days
from the date of purchase from 3Com or its authorized
reseller. 3Com warrants the media containing software
against failure during the warranty period. No updates are
provided. 3Com's sole obligation under this express
warranty shall be, at 3Com's option and expense, to refund
the purchase price paid by Customer for any defective
software product, or to replace any defective media with
software which substantially conforms to applicable 3Com
published specifications. Customer assumes responsibility
for the selection of the appropriate applications program
and associated reference materials. 3Com makes no
warranty or representation that its software products will
meet Customer’s requirements or work in combination
with any hardware or applications software products
provided by third parties, that the operation of the
software products will be uninterrupted or error free, or
that all defects in the software products will be corrected.
For any third party products listed in the 3Com software
product documentation or specifications as being
compatible, 3Com will make reasonable efforts to provide
compatibility, except where the non-compatibility is caused
by a "bug" or defect in the third party's product or from
use of the software product not in accordance with 3Com’s
published specifications or user manual.

THIS 3COM PRODUCT MAY INCLUDE OR BE BUNDLED
WITH THIRD PARTY SOFTWARE, THE USE OF WHICH IS
GOVERNED BY A SEPARATE END USER LICENSE
AGREEMENT. THIS 3COM WARRANTY DOES NOT APPLY
TO SUCH THIRD PARTY SOFTWARE. FOR THE APPLICABLE
WARRANTY, PLEASE REFER TO THE END USER LICENSE
AGREEMENT GOVERNING THE USE OF SUCH SOFTWARE.

Year 2000 Warranty

In addition to the Hardware Warranty stated above, 3Com
warrants that each product sold or licensed to Customer on
and after January 1, 1998 that is date sensitive will
continue performing properly with regard to such date
data on and after January 1, 2000, provided that all other
products used by Customer in connection or combination
with the 3Com product, including hardware, software, and
firmware, accurately exchange date data with the 3Com
product, with the exception of those products identified at
3Com's Web site,

http://www.3com.com/products/yr2000.html

3Com Corporation Limited Warranty

45

as not meeting this standard. If it appears that any product
that is stated to meet this standard does not perform
properly with regard to such date data on and after January
1, 2000, and Customer notifies 3Com before the later of
April 1, 2000, or ninety (90) days after purchase of the
product from 3Com or its authorized reseller, 3Com shall,
at its option and expense, provide a software update which
would effect the proper performance of such product,
repair such product, deliver to Customer an equivalent
product to replace such product, or if none of the
foregoing is feasible, refund to Customer the purchase
price paid for such product.

Any software update or replaced or repaired product will
carry a Year 2000 Warranty for ninety (90) days after
purchase or until April 1, 2000, whichever is later.

Obtaining Warranty Service

Customer must contact a 3Com Corporate Service Center
or an Authorized 3Com Service Center within the
applicable warranty period to obtain warranty service

5: R

46

C

HAPTER

EGULATORY INFORMATION AND LIMITED WARRANTY

authorization. Dated proof of purchase from 3Com or its
authorized reseller may be required. Products returned to
3Com's Corporate Service Center must be pre-authorized
by 3Com with a User Service Order (USO) number marked
on the outside of the package, and sent prepaid and
packaged appropriately for safe shipment, and it is
recommended that they be insured or sent by a method
that provides for tracking of the package. The repaired or
replaced item will be shipped to Customer, at 3Com's
expense, not later than thirty (30) days after 3Com receives
the defective product.

WARRANTIES EXCLUSIVE

IF A 3COM PRODUCT DOES NOT OPERATE AS
WARRANTED ABOVE, CUSTOMER'S SOLE REMEDY FOR
BREACH OF THAT WARRANTY SHALL BE REPAIR,
REPLACEMENT, OR REFUND OF THE PURCHASE PRICE
PAID, AT 3COM'S OPTION. TO THE FULL EXTENT ALLOWED
BY LAW, THE FOREGOING WARRANTIES AND REMEDIES
ARE EXCLUSIVE AND ARE IN LIEU OF ALL OTHER
WARRANTIES, TERMS, OR CONDITIONS, EXPRESS OR
IMPLIED, EITHER IN FACT OR BY OPERATION OF LAW,
STATUTORY OR OTHERWISE, INCLUDING WARRANTIES,
TERMS, OR CONDITIONS OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE, SATISFACTORY QUALITY,
CORRESPONDENCE WITH DESCRIPTION, AND
NON-INFRINGEMENT, ALL OF WHICH ARE EXPRESSLY
DISCLAIMED. 3COM NEITHER ASSUMES NOR AUTHORIZES
ANY OTHER PERSON TO ASSUME FOR IT ANY OTHER
LIABILITY IN CONNECTION WITH THE SALE, INSTALLATION,
MAINTENANCE OR USE OF ITS PRODUCTS.

3COM SHALL NOT BE LIABLE UNDER THIS WARRANTY IF
ITS TESTING AND EXAMINATION DISCLOSE THAT THE
ALLEGED DEFECT OR MALFUNCTION IN THE PRODUCT
DOES NOT EXIST OR WAS CAUSED BY CUSTOMER'S OR
ANY THIRD PERSON'S MISUSE, NEGLECT, IMPROPER
INSTALLATION OR TESTING, UNAUTHORIZED ATTEMPTS TO
OPEN, REPAIR OR MODIFY THE PRODUCT, OR ANY OTHER
CAUSE BEYOND THE RANGE OF THE INTENDED USE, OR
BY ACCIDENT, FIRE, LIGHTNING, OTHER HAZARDS, OR
ACTS OF GOD.

LIMITATION OF LIABILITY

TO THE FULL EXTENT ALLOWED BY LAW, 3COM ALSO
EXCLUDES FOR ITSELF AND ITS SUPPLIERS ANY LIABILITY,
WHETHER BASED IN CONTRACT OR TORT (INCLUDING
NEGLIGENCE), FOR INCIDENTAL, CONSEQUENTIAL,
INDIRECT, SPECIAL, OR PUNITIVE DAMAGES OF ANY KIND,
OR FOR LOSS OF REVENUE OR PROFITS, LOSS OF
BUSINESS, LOSS OF INFORMATION OR DATA, OR OTHER
FINANCIAL LOSS ARISING OUT OF OR IN CONNECTION
WITH THE SALE, INSTALLATION, MAINTENANCE, USE,
PERFORMANCE, FAILURE, OR INTERRUPTION OF ITS
PRODUCTS, EVEN IF 3COM OR ITS AUTHORIZED RESELLER
HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
DAMAGES, AND LIMITS ITS LIABILITY TO REPAIR,
REPLACEMENT, OR REFUND OF THE PURCHASE PRICE
PAID, AT 3COM'S OPTION. THIS DISCLAIMER OF LIABILITY
FOR DAMAGES WILL NOT BE AFFECTED IF ANY REMEDY
PROVIDED HEREIN SHALL FAIL OF ITS ESSENTIAL PURPOSE.

Disclaimer

Some countries, states, or provinces do not allow the
exclusion or limitation of implied warranties or the
limitation of incidental or consequential damages for
certain products supplied to consumers, or the limitation of
liability for personal injury, so the above limitations and
exclusions may be limited in their application to you. When
the implied warranties are not allowed to be excluded in
their entirety, they will be limited to the duration of the
applicable written warranty. This warranty gives you
specific legal rights which may vary depending on local law.

3Com Corporation Limited Warranty

47

Governing Law

This Limited Warranty shall be governed by the laws of the
State of California, U.S.A. excluding its conflicts of laws
principles and excluding the United Nations Convention on
Contracts for the International Sale of Goods.

48

C

HAPTER

5: R

EGULATORY INFORMATION AND LIMITED WARRANTY

3Com U.S. Robotics Cable Modem CMX Wall-mounting Template

6

For complete instructions, see the

Getting Started Guide

.

T

W

EMPLATE

ALL

-

MOUNTING

50

C

HAPTER

6: W

ALL-MOUNTING TEMPLATE