Black Box MD1621A User Manual

JUNE 2001

MD1621A

Mini-Modem

(33.6 kbps Data/Fax Modem)

CUSTOMER SUPPORT INFORMATION

Order toll-free in the U.S. 24 hours, 7 A.M. Monday to midnight Friday: 877-877-BBOX
FREE technical support, 24 hours a day, 7 days a week: Call 724-746-5500 or fax [phone]
Mail order: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
Web site: www.blackbox.com • E-mail: [e-mail]

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

FEDERAL COMMUNICATIONS COMMISSION

AND

INDUSTRY CANADA

RADIO FREQUENCY INTERFERENCE STATEMENTS

This equipment generates, uses, and can radiate radio frequency energy
and if not installed and used properly, that is, in strict accordance with the
manufacturer’s instructions, may cause interference to radio communication.
It has been tested and found to comply with the limits for a Class A computing
device in accordance with the specifications in Subpart J of Part 15 of FCC rules,
which are designed to provide reasonable protection against such interference
when the equipment is operated in a commercial environment. Operation of
this equipment in a residential area is likely to cause interference, in which case
the user at his own expense will be required to take whatever measures may be
necessary to correct the interference.

Changes or modifications not expressly approved by the party responsible
for compliance could void the user’s authority to operate the equipment.

This digital apparatus does not exceed the Class A limits for radio noise emission from
digital apparatus set out in the Radio Interference Regulation of Industry Canada.

Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites
applicables aux appareils numériques de classe A prescrites dans le Règlement sur le
brouillage radioélectrique publié par Industrie Canada.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

NORMAS OFICIALES MEXICANAS (NOM)

ELECTRICAL SAFETY STATEMENT

INSTRUCCIONES DE SEGURIDAD

1. Todas las instrucciones de seguridad y operación deberán ser leídas
antes de que el aparato eléctrico sea operado.

2. Las instrucciones de seguridad y operación deberán ser guardadas
para referencia futura.

3. Todas las advertencias en el aparato eléctrico y en sus instrucciones
de operación deben ser respetadas.

4. Todas las instrucciones de operación y uso deben ser seguidas.

5. El aparato eléctrico no deberá ser usado cerca del agua—por ejemplo,
cerca de la tina de baño, lavabo, sótano mojado o cerca de una alberca,
etc..

6. El aparato eléctrico debe ser usado únicamente con carritos o pedestales
que sean recomendados por el fabricante.

7. El aparato eléctrico debe ser montado a la pared o al techo sólo como sea
recomendado por el fabricante.

8. Servicio—El usuario no debe intentar dar servicio al equipo eléctrico más
allá a lo descrito en las instrucciones de operación. Todo otro servicio
deberá ser referido a personal de servicio calificado.

9. El aparato eléctrico debe ser situado de tal manera que su posición no
interfiera su uso. La colocación del aparato eléctrico sobre una cama,
sofá, alfombra o superficie similar puede bloquea la ventilación, no se
debe colocar en libreros o gabinetes que impidan el flujo de aire por los
orificios de ventilación.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

10. El equipo eléctrico deber ser situado fuera del alcance de fuentes de calor
como radiadores, registros de calor, estufas u otros aparatos (incluyendo
amplificadores) que producen calor.

11. El aparato eléctrico deberá ser connectado a una fuente de poder sólo
del tipo descrito en el instructivo de operación, o como se indique en
el aparato.

12. Precaución debe ser tomada de tal manera que la tierra fisica y la
polarización del equipo no sea eliminada.

13. Los cables de la fuente de poder deben ser guiados de tal manera que
no sean pisados ni pellizcados por objetos colocados sobre o contra ellos,
poniendo particular atención a los contactos y receptáculos donde salen
del aparato.

14. El equipo eléctrico debe ser limpiado únicamente de acuerdo
a las recomendaciones del fabricante.

15. En caso de existir, una antena externa deberá ser localizada lejos
de las lineas de energia.

16. El cable de corriente deberá ser desconectado del cuando el equipo
no sea usado por un largo periodo de tiempo.

17. Cuidado debe ser tomado de tal manera que objectos liquidos
no sean derramados sobre la cubierta u orificios de ventilación.

18. Servicio por personal calificado deberá ser provisto cuando:

A: El cable de poder o el contacto ha sido dañado; u

B: Objectos han caído o líquido ha sido derramado dentro

del aparato; o

C: El aparato ha sido expuesto a la lluvia; o

D: El aparato parece no operar normalmente o muestra

un cambio en su desempeño; o

E: El aparato ha sido tirado o su cubierta ha sido dañada.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

TRADEMARKS

The trademarks mentioned in this manual are the sole
property of their owners.

NAMING CONVENTIONS USED IN THIS MANUAL

In the software you received, the Mini-Modem is called
the Multi-Modem or the MT2834ADX. This is the
correct software for your Mini-Modem.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

CONTENTS

1. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.2 What the Package Includes . . . . . . . . . . . . 14

3. Quick Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . 16

3.2 Safety Warnings. . . . . . . . . . . . . . . . . . . . . . 16

3.3 What You’ll Need . . . . . . . . . . . . . . . . . . . . 17

3.4 Step 1: Assemble the Modem. . . . . . . . . . . 18

3.5 Step 2: Connect the Modem to Your

System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.5.1 RS-232 Connection . . . . . . . . . . . . . . 21

3.5.2 LINE Connection. . . . . . . . . . . . . . . . 21

3.5.3 PHONE Connection . . . . . . . . . . . . . 21

3.5.4 POWER Connection . . . . . . . . . . . . . 22

3.5.5 Power-On Test . . . . . . . . . . . . . . . . . . 22

3.6 Step 3: Install the Modem in Windows 95

or 98 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

3.6.1 Adding the Mini-Modem to

Windows 95 or 98 . . . . . . . . . . . . . . . . 23

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

3.6.2 Removing Your Old Modem from

Windows 95 or 98 . . . . . . . . . . . . . . . . 24

3.7 Step 4: Install and Configure Your

Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Third Party Communications Software . . . 25

4. Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4.1 What Can I Do with My Mini-Modem? . . . 29

4.2 Required Equipment . . . . . . . . . . . . . . . . . 32

4.3 Connections . . . . . . . . . . . . . . . . . . . . . . . . 34

4.3.1 Connecting to the Computer

(“RS-232”) . . . . . . . . . . . . . . . . . . . . . . 35

4.3.2 Connecting to the Telephone Line

(“LINE”) . . . . . . . . . . . . . . . . . . . . . . 35

4.3.3 Connecting a Telephone Set

(“PHONE”) . . . . . . . . . . . . . . . . . . . . 35

4.3.4 Connecting to Power (“POWER”) . . 36

4.3.5 Surge Protectors and Lightning . . . . 37

4.4 Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . 37

4.5 Speed Indicator Blink Rates. . . . . . . . . . . . 40

5. AT Commands, S-Registers and Result

Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

5.1 AT Commands . . . . . . . . . . . . . . . . . . . . . . 42

5.2 S-Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 74

5.3 Result Codes . . . . . . . . . . . . . . . . . . . . . . . . 77

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

6. Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . 79

6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . 79

6.2 None of the LEDs Light When the

Modem Is On. . . . . . . . . . . . . . . . . . . . . . . . 80

6.3 The Modem Does Not Respond to

Commands. . . . . . . . . . . . . . . . . . . . . . . . . . 81

6.4 The Modem Dials But Cannot Make a

Connection . . . . . . . . . . . . . . . . . . . . . . . . . 85

6.5 The Modem Disconnects While Online . . 89

6.6 The Modem Cannot Connect When

Answering . . . . . . . . . . . . . . . . . . . . . . . . . . 90

6.7 File Transfer Is Slower Than It

Should Be. . . . . . . . . . . . . . . . . . . . . . . . . . . 91

6.8 I Am Losing Data . . . . . . . . . . . . . . . . . . . . 92

6.9 I Am Getting Garbage Characters on

the Monitor . . . . . . . . . . . . . . . . . . . . . . . . . 93

6.10 My Fax and Communications Software

Won’t Run at the Same Time. . . . . . . . . . . 94

Appendix A: Regulatory Information . . . . . . . . . 95

A.1 Single-User Software License

Agreement . . . . . . . . . . . . . . . . . . . . . . . . . . 95

A.2 FCC Regulations for Telephone Line

Interconnection. . . . . . . . . . . . . . . . . . . . . . 95

A.3 Canadian Limitations Notice. . . . . . . . . . . 96

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Appendix B: Service and Calling for

Technical Support . . . . . . . . . . . . . . . . . . . . . . 98

B.1 Calling for Technical Support. . . . . . . . . . 98

B.2 About the Internet . . . . . . . . . . . . . . . . . . . 98

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

1. Specifications

Data Rates (Modem) — 33.6 kbps and 31.2 kbps,

28.8, 26.4, 24, 19.2, 16.8, 14.4, and 12 kbps,
9600 bps, 7200, 4800, 2400, 1200 and 0-300 bps

Data Rates (Fax) — 14,400, 9600, 4800

and 2400 bps

Data Format (Modem) — Serial, Binary,

Asynchronous

Compatibility (Modem) — ITU-T V.34, AT&T

V.32terbo, ITU-T V.32bis, V.32, Bell 212A and
103/113, ITU-T V.22, V.22bis, V.29, V.42, V.42bis

Compatibility (Fax) — ITU-T Group 3, T.4, T.30,

V.21, V.27ter, V.29, V.17, and EIA TR29.2

Error Correction — ITU-T V.42 (LAP-M or MNP 2,

3 or 4)

Data Compression — ITU-T V.42bis (4:1

throughput) or MNP 5 (2:1 throughput)

Speed Conversion — Serial-port data rates

adjustable to 300, 1200, 2400, 4800, and 9600 bps,

19.2 kbps, 38.4, 57.6, and 115.2 kbps

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Mode of Operation — Half- or full-duplex over dial-

up lines; automatic or manual dialing, automatic
or manual answer

Flow Control — XON/XOFF, hardware

(RTS/CTS), HP (ENQ/ACK)

Intelligent Features — Fully AT command

compatible, autodial, redial, repeat dial, pulse
or tone dial, dial pauses, call status display, auto
parity and data-rate selections, keyboard­controlled modem options, on-screen displays for
modem option parameters, command lines of up
to 60 characters each, and help menus

Command Buffer — 60 characters

Modem Modulations — FSK at 300 bps, PSK at

1200 bps, QAM at 2400, 4800, and 9600 bps (non­trellis), QAM with trellis-coded modulation (TCM)
at 9600 bps, 12 kbps, 14.4, 16.8, 19.2, 21.6, 24,

26.4, 28.8, 31.2, and 33.6 kbps

Fax Modulations — V.21 CH2 FSK at 300 bps,

V.27ter DPSK at 2400 and 4800 bps, V.29 QAM
at 7200 and 9600 bps, V.17 TCM at 7200 bps,
9600 bps, 12 kbps, and 14.4 kbps

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Carrier Frequencies, ITU-T V.34 — 1600, 1646,

1680, 1800, 1829, 1867, 1920, 1959, 2000 Hz

Carrier Frequencies, AT&T V.32 terbo/ITU-T

V.32bis/V.32 — 1800 Hz

Carrier Frequencies, V.22bis/V.22 or Bell 212A

Standard (2400 & 1200 bps) —Transmit originate:

1200 Hz; Transmit answer: 2400 Hz; Receive
originate: 2400 Hz; Receive answer: 1200 Hz

Carrier Frequencies, Bell 103/113 (300 bps)—

Transmit originate: 1270 Hz mark, 1070 Hz space;
Receive originate: 2225 Hz mark, 2025 Hz space;
Transmit answer: 2225 Hz mark, 2025 Hz space;
Receive answer: 1270 Hz mark, 1070 Hz space

Fax Carrier Frequencies — V.21 Ch2 (half duplex):

1650 Hz mark, 1850 Hz space for transmit
originate; 1650 Hz mark, 1850 Hz space for
transmit answer; V.27ter: 1800 Hz
originate/answer; V.29 QAM: 1700 Hz
originate/answer; V.17 TCM 1800 Hz
originate/answer

Transmit Level — -13 dBm

Frequency Stability — ±-0.01%

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Receiver Sensitivity — -43dBm under worst-case

conditions

AGC Dynamic Range — 43 dB

Interface Connectors — EIA RS-232C/ITU-T

V.24/V.28 DB25 RS-232C connector; two RJ-11
phone jacks (one RJ-11 jack on UK and
international modems), power jack

Cables — One 14-foot (4.3-m) RJ-11 phone cable

(USA); external power transformer and cord

NOTE

Any cables connected to the computer should be shielded
to reduce interference.

Diagnostics — Power-on self test, local analog loop,

local digital loop, remote digital loop

Indicators — LEDs for Transmit Data, Receive Data,

Carrier Detect, 33.6 kbps, 14.4 kbps, 9600 bps, Off
Hook, Terminal Ready, Error Correction, Fax

Speaker — Command-controlled speaker for call

progress monitoring

Manual Control — Power switch

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Enviromental — Temperature range 0 to 50 °C

(32 to 120 °F); Humidity range 20 to 90%
(non-condensing)

Power Requirements — 100-130 VAC, 50/60 Hz,

0.1A/5W; two-prong outlet-mounted transformer
(included); 230V/50 Hz optional (international)

Regulatory Compliance — UL, CUL, CSA, FCC

Size — 1.15"H x 4.25"W x 5.8"D

(2.9 x 10.8 x 14.8 cm)

Weight — 0.5 lb. (0.3 kg)

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

2. Introduction

2.1 General

The Mini-Modem (MD1621A) complies with the
enhanced V.34 standard for a top speed of 33,600 bps.
It’s downward-compatible with all previous standards,
including V.32terbo (19,600 bps), V.32bis (14,400 bps),
V.32 (9600 bps), V.22bis (2400 bps), and V.22 (1200
bps)—and it’s a full-duplex intelligent modem with V.42
error correction, V.42bis data compression, and V.17
(14,400 bps), Class 2, Group 3 fax capabilities.

2.2 What the Package Includes

Make sure you have all of the following components
before trying to operate your modem:

• One Mini-Modem (MD1621A)

• One DC power supply

• One set of four plastic feet

• One telephone cable

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

• This User manual

• Communications (datacomm) software

If any of these items are missing, please contact

Black Box immediately at 724-746-5500.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

3. Quick Start

3.1 Introduction

We know you’re eager to get your Mini-Modem up and
running, so we’ll skip the features for now, and show you
step-by-step how to set it up, check it out, and make your
first calls.

3.2 Safety Warnings

• Never install telephone wiring during a lightning
storm.

• Never install a telephone jack in a wet location
unless the jack is specifically designed for wet
locations.

• Never touch uninsulated telephone wires or
terminals unless the telephone line has been
disconnected at the network interface.

• Use caution when installing or modifying
telephone lines.

• Avoid using a telephone (other than a cordless
type) during an electrical storm; there may be a
remote risk of electrical shock from lightning.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

• Do not use a telephone in the vicinity of a gas leak.

3.3 What You’ll Need

Before starting, please make sure you have everything
you need:

We supply:

• The Mini-Modem (MD1621A)

• A DC power supply module

• One set of four plastic feet

• One telephone cable

• Communications (datacomm) software

• This user manual

You supply:

• A computer with an unused external serial port

• A shielded RS-232 serial cable with a male DB25
connector on one end and a connector to match
your computer’s serial port on the other end

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

• A nearby AC power outlet

• A nearby telephone line jack

If you are unfamiliar with computers, please see

Chapter 4, Features, for more information on the
required equipment before you proceed.

3.4 Step 1: Assemble the Modem

The only assembly required is to mount the feet on the
bottom of the modem. Simply peel the four self-adhesive
plastic feet off the backing strip and press them into the
recesses on the bottom of the modem. You can also use
self-adhesive Velcro patches (not included) to mount
the modem on a vertical surface or to keep it from being
dislodged on a horizontal surface. If you use Velcro
patches, we recommend that you mount them where
they will not obscure the labels on the bottom of the
modem.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Figure 3-1. Mounting the feet.

3.5 Step 2: Connect the Modem to Your System

Placing the Mini-Modem in a convenient location,
connect it to your computer’s serial port, to the
telephone line, to AC power, and, optionally, to your
telephone.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Figure 2-2. Mini-Modem connections.

POWER RS-232 PHONE LINE

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

3.5.1 RS-232 C

ONNECTION

Plug one end of the serial cable into the RS-232
connector on the modem, and the other end into a
serial port on your computer, such as COM1 or COM2.

3.5.2 LINE C

ONNECTION

Plug one end of the phone cable into the Mini-Modem’s
LINE jack, and the other end into a phone-line wall jack.

NOTE

The Mini-Modem’s LINE jack is not interchangeable with
the PHONE jack. Do not plug the phone into the LINE jack
or the line cable into the PHONE jack.

NOTE

The Federal Communications Commission (FCC), Industry
Canada, and the British Approvals Board for
Telecommunications (BABT) impose certain restrictions on
equipment connected to public telephone systems. See
Appendix A for more information.

3.5.3 PHONE C

ONNECTION

You may optionally plug a telephone into the Mini­Modem’s PHONE jack. This jack is provided as a
convenience; you may also plug a telephone into a
duplex jack inserted into your wall jack.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

3.5.4 POWER C

ONNECTION

Plug the power-supply module into an AC power outlet
or power strip. Plug the power supply’s cable into the
POWER jack on the modem.

NOTE

Use only the power supply supplied with the Mini-Modem.
Using any other power supply could damage the modem.

3.5.5 P

OWER

-ONT

EST

Test the modem by turning it on (a power on/off switch
is located on the right side). When you apply power, the
modem performs a diagnostic self-test, indicated by the
speed indicators flashing in sequence for a second or
two, after which the 33 indicator should light. If this
does not happen, check that the power switch is on, the
power supply is solidly connected, and the AC outlet is
live. If these measures do not work, see Chapter 7,
Troubleshooting.

3.6 Step 3: Install the Modem in Windows 95 or 98

If you are using Windows 95 or 98, you must install the
modem in the operating system. (If you are using
another operating system, you may skip this step.)

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

3.6.1 A

DDING THEMINI

-M

ODEM TOWINDOWS

95

OR

98

1. Click the Start button, point to Settings, and click
Control Panel.

2. Double-click the Modems icon. If no modem is
currently installed, the Install New Modem wizard
appears. If a modem is already installed, the
Modems Properties sheet appears; click Add to
go to the Install New Modem wizard.

3. Click Next in the Install New Modem wizard.
Windows searches for your new modem and asks
you to verify its selection.

NOTE

If Windows cannot find a modem, your modem may be
turned off, it may be plugged into the wrong connector on
your computer, or the serial cable may be faulty. See
Sections 5.2 and 5.3.

4. If Windows identifies your modem correctly as a
MultiModem MT2834ZDX, click Next to install
the modem. After the modem is installed, click
Finish to exit.

5. If Windows cannot identify your modem (for
instance, if it identifies your modem as a “Standard

24

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Modem”), click Change. A dialog box with a list of
manufacturers and a list of modems appears.

6. Select “MultiTech Systems” from the
Manufacturers list box, then select “MultiModem
MT2834ZDX” from the Models list box.

7. Click Next. Windows installs and configures the
modem.

8. Click Finish to exit.

3.6.2 R

EMOVINGYOUROLDMODEM FROMWINDOWS

95

OR

98

When your Mini-Modem replaces another modem, the
old modem installation remains in Windows after you
install the new modem, and the old modem is still
selected in HyperTerminal and other Windows 95 or 98
applications. Although you can change the application
connection descriptions one at a time, it is easier to
force Windows 95 or 98 applications to use the Mini­Modem by removing the old modem from Windows.

1. Click the Start button, point to Settings, and click
Control Panel.

2. Double-click the Modems icon to open the
Modems Properties sheet.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

3. In the list box, select the old modem.

4. Click Remove, then click Close.

5. The next time you dial a HyperTerminal
connection, it will select your new modem
and ask you to confirm the selection.

3.7 Step 4: Install and Configure Your Software

You must have communications software installed in
your computer to use the Mini-Modem. If you wish to
use communications software that is already installed,
you should reconfigure it for the Mini-Modem;
otherwise, install the data and fax communications
software provided with the Mini-Modem.

T

HIRD-PARTYCOMMUNICATIONSSOFTWARE

1. Turn on your computer and run your
communications software.

2. Find the dialog box or menu that lets you specify
your modem. (In Windows Terminal, select
Settings, Modem Commands; in HyperTerminal,
select File, Properties, Phone Number; in
ProComm Plus for Windows, select Window,

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Setup, Advanced; and in MultiExpress Terminal
for Windows, select Setup, Terminal, Modem.)

3. Choose the MultiModemZDX or MT2834ZDX
from the software’s modem list.

4. Change the modem initialization string, if
necessary. In most circumstances, AT&FX4S0=0
works best for a PC, and AT&FX4&E13&D0S0=0
works best for a Macintosh. For CompuServe,
include &E0&E14S7=60 in the string; if you use
WinCIM, include &E5 for WinCIM’s software flow
control. If you want the modem to always answer
the phone, delete S0=0 from the string.
Depending on the software, you may have
to end the string with a carriage return (^M).

NOTE

To change the modem’s default initialization string, type the
new commands in the software’s terminal window, adding
the command &W to store it in the modem’s nonvolatile
memory; e.g., AT&FX4S0=0&W.

5. Select the port the modem is connected to
(normally COM1 or COM2).

6. Ideally, if you use data compression, you should
set your serial-port baud rate to four times the

27

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

modem’s maximum transmission speed or faster;
however, not all serial ports can handle speeds
that high. Set the serial-port baud rate to 115,200
bps if your computer has a high-speed serial port
with a 16550AFN UART or equivalent and
Windows 95 or 98; set it to 57,600 bps if it has
Windows 3.1x. If you have an older computer with
a 14550 UART, set it to 19,200 bps. Older
Macintosh computers can use a serial-port baud
rate of 57,600 bps, and newer ones, 115,200 bps.

To see what UART is in your serial port if you have
Windows 3.1x, select File, Run in Program
Manager, type MSD, and press RETURN. Select
COM Ports to see the UART type. If you have
Windows 95 or 98, select Start, Settings, Control
Panel, and double-click on the Modems icon. In
the Modems Properties dialog box, click the
Diagnostics tab, click the port the modem is
connected to, and click More Info to see the
UART type. Note: Both programs may identify a
14550 UART as an 8250A UART. If you have an
80386 or later computer, your UART is most likely
a 14550 or 16550AFN.

7. If the software has an autobaud selection, make
sure it is disabled. Autobaud applies only to older
modems, and can cause problems if enabled.

28

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

8. If the software allows you to edit the no-connect
messages (NO CARRIER, BUSY, NO ANSWER,
NO DIALTONE), make sure there is no space
between DIAL and TONE in NO DIALTONE.

9. Refer to the software manual or online Help for
other configuration choices; in most cases you can
accept the default values.

29

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

4. Features

4.1 What Can I Do with My Mini-Modem?

You can use your Mini-Modem to access commercial
online information services such as CompuServe,
America Online, Genie, and Prodigy. These services
provide access to databases, encyclopedias, stock reports,
news, weather, and shopping. They provide electronic
mail (e-mail) links to subscribers of the same and other
services. Public message areas called forums allow
subscribers to trade information and opinions on a vast
array of topics from A to Z, while vendor forums provide
hardware and software support from manufacturers.
Online services also allow you to upload and download
computer programs, data files, and updated software
such as video and printer drivers.

The Mini-Modem can also connect you to the
Internet, an international computer network of
universities, libraries, businesses, and government
agencies. Like the commercial online services, the
Internet provides e-mail services, public message areas,
and access to information and software, much of it easily
accessed through the World-Wide Web.

30

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

You can also use the Mini-Modem to dial into bulletin­board services (BBSs). BBSs offer some of the services
provided by online information services—usually email,
public message areas, and file transfers. Most are run as
hobbies by individuals, but some are services provided
by companies. Though some charge an annual fee,
many are free.

Other uses include direct links to friends with
modems, to banks, and to service bureaus. You can also
telecommute with your fax modem—work at home
while communicating with the office by modem or fax.

And, of course, you can use your Mini-Modem to send
and receive faxes anywhere in the world, enabling you to
communicate quickly with businesses and other
organizations that do not maintain BBSs.

The Mini-Modem automatically adjusts to line
conditions and to the capabilities of the modem it
connects to, resulting in the highest transmission speed,
the most accurate error correction, and the most
efficient data compression possible for each connection.
The Mini-Modem follows the most recent revision of the
V.34 specification for data rates up to 33,600 bps.

31

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

The Mini-Modem’s features include:

• Support of data rates of 33,600 and 31,200 bps,
28,800, 26,400, 24,000, 21,600, 19,200, 16,800,
14,400, 12,000, 9600, 7200, 4800, 2400, 1200, and
300 bps for communicating with older modems as
well as with other V.34 modems.

• Automatic fallback to slower speeds in noisy line
conditions, and fall-forward to faster speeds as
conditions improve.

• ITU-T V.42 LAP-M and MNP Classes 2–4 error
correction.

• Data-transfer rates up to 115,200 bps with V.42bis
data compression.

• Serial-port data rates adjustable to 115,200 bps.

• Autodial, redial, pulse (rotary), dial, and touch­tone dial.

• Dial-tone and busy-signal detection for reliable
call-progress reporting.

• Compatibility with the standard AT command set
used by most communication programs.

32

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

• On-screen help menus.

• Nonvolatile memory for storage of custom settings
and two telephone numbers.

• Sends and receives faxes from your computer at
14,400, 9600, 4800, and 2400 bps.

• Responds to EIA TR29.2 Class 2 fax commands.

4.2 Required Equipment

In addition to the contents of the Mini-Modem package,
you need the following equipment.

• Computer: You can connect the Mini-Modem to
any computer with an RS-232C/V.24 serial port,
such as the IBM PC, XT, AT, and PS/2 computers,
and most PC compatibles. It can also be connected
to the RS-422 serial ports on Apple Macintosh
computers. To use your Mini-Modem at its highest
speeds, a PC must have a serial port with a
16550AFN UART, which can safely handle data
at rates up to 115,200 bps. Almost all Macintoshe
computers can handle data rates up to 57,000 bps,
while the newer ones can handle data rates up
to 115,000 bps.

33

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

• Serial Cable: To connect the Mini-Modem to
your computer, you must provide a serial cable,
obtainable at computer stores and many office
supply stores. The cable should have a male DB25
connector at the modem end. For IBM and
compatible computers, the other end may have
a female DB25 connector or a female DB9
connector, depending on your computer. Most
Macintosh computers require a round, 8-pin, mini­DIN connector. The Macintosh serial cable should
be wired for hardware flow control. To reduce
electrical interference, the FCC requires that the
cable be shielded.

• Telephone Line: You must have a telephone line
with a jack (connector) that accepts the cable that
comes with the Mini-Modem. If you do not have a
telephone jack near your computer, you should
install one before proceeding.

In North America, do-it-yourself telephone
extension kits and accessories are available
wherever telephones are sold. You may also
hire an independent contractor or your local
telephone company to do the work. If you want
a separate line for your fax modem, you must
contact your telephone company.

34

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

• Communications Software: To operate the Mini­Modem, you must have data-communications
(datacomm) and fax-communications software.
The Mini-Modem comes with a data and fax
communications package. You must have
Microsoft Windows 3.1 or later to run this
software. If you require software for DOS or for
the Macintosh operating system, please contact
Technical Support at 724-746-5500. The Mini­Modem is also compatible with other datacomm
and fax programs.

4.3 Connections

All models connect to your computer (“RS-232”), to a
telephone line (“LINE”), and to a power source
(“POWER”).

Figure 4-1. Connectors.

POWER RS-232 PHONE LINE

35

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

4.3.1 C

ONNECTING TO THECOMPUTER

(“RS-232”)

Using a matching serial cable, connect the RS-232
connector on the modem to one of the serial ports on
the back of your computer. On an IBM PC or
compatible, there are usually two serial ports named
“COM1” and “COM2.” COM1 typically uses a DB9 male
connector, whereas COM2 may use a DB25 male
connector. Most Apple Macintosh computers use round
mini-DIN-8 connectors for the serial ports. Choose the
one marked with the icon of a telephone; the Macintosh
gives priority to that port and will not interrupt your
communications link. Be sure to tighten the mounting
screws on the DB connectors.

4.3.2 C

ONNECTING TO THETELEPHONELINE

(“LINE”)

Plug one end of the cable provided with the Mini­Modem into the telephone jack in your home or office.
Plug the other end into the LINE jack on the Mini­Modem.

4.3.3 C

ONNECTING ATELEPHONESET

(“PHONE”)

If you wish to connect a telephone to the same line
as the Mini-Modem, you may plug it into the latter’s
PHONE jack. This connector is provided as a

36

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

convenience; you may also connect your telephone to
a duplex jack inserted into your wall jack.

NOTE

The PHONE jack is not interchangeable with the LINE jack;
do not plug the telephone into the LINE jack or vice-versa.

4.3.4 C

ONNECTING TO

P

OWER

(“POWER”)

Low voltage DC power is supplied to the Mini-Modem
through a modular power supply included with the
modem. Plug the power supply module into a
convenient AC power outlet or surge protector. Plug
the connector on the other end of the power cord into
the POWER jack on the modem. A power on/off switch
is located on the right side of the modem.

NOTE

Use only the power supply supplied with the Mini-Modem.
Using any other power supply could damage the modem.

As soon as you apply power to the modem, it will
perform a diagnostic self-test, indicated by the speed
LEDs flashing in sequence for approximately two
seconds, after which the 33 indicator should light. If this
does not happen, check that the power switch is on, the
power supply is solidly connected, and the AC outlet is
live.

37

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

4.3.5 S

URGEPROTECTORS ANDLIGHTNING

Power surges and other transient voltages on power
lines, such as those caused by lightning strikes, can
damage or destroy your modem. Damaging voltages
can also enter your modem through the telephone line,
especially during an electrical storm. Therefore, we
recommend that you plug the Mini-Modem into a surge
protector rather than directly into a wall outlet,
preferably a surge protector that provides protection
against electrical spikes on the telephone line as well
as on the power line. Note that not even a surge
protector can guard against damage from a nearby
lightning strike. During an electrical storm, your safest
course is to unplug your computer equipment from
both the power outlet and the telephone line.

4.4 Front Panel

Figure 4-2. Mini-Modem front panel.

9633

38

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

The Mini-Modem has ten LED indicators on the front
panel that indicate status, configuration, and activity:

• TD: Transmit Data. The TD LED lights when the
modem is transmitting data to another modem.
The state of the LED matches the TD circuit on
pin 2 of the RS-232C/V.24 interface.

• RD: Receive Data. The RD LED lights when the
modem is receiving data from another modem.
The state of the LED matches that of the RD
circuit on pin 3 of the RS-232C/V.24 interface.

• CD: Carrier Detect. The CD LED lights when
the modem detects a valid carrier signal from
another modem. It is on when the modem is
communicating with the other modem and off
when the link is broken.

• 33: 28,800–33,600 bps. The 33 LED lights by itself
when the modem connects at 28,800 bps, blinks
slowly to indicate 31,200 bps, and blinks fast to
indicate 33,600 bps operation. This LED also
lights or blinks in combination with the 14 LED
to indicate speeds between 16,800 and 26,400 bps
(see the table on page 41).

39

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

• 14: 14,400 bps. The 14 LED lights by itself when
the modem connects at 14,400 bps. The 14 LED
lights or blinks in combination with the 28 LED
to indicate speeds between 16,800 and 26,400 bps
(see the table on page 41). It lights together with
the 96 LED to indicate a speed of 12,000 bps.

• 96: 9600 bps. The 96 LED lights when the modem
connects at 9600 bps. If no speed LED lights, the
modem is operating at less than 9600 bps.

• OH: Off-Hook. The OH LED lights when the
modem is off-hook, which occurs when the
modem is dialing, online, or answering a call.
The LED flashes when the modem pulse-dials.

• TR: Terminal Ready. The TR LED lights when

a datacomm program initializes the modem. It
means the modem is ready for an outgoing or
incoming call. It goes off when the datacomm
program disconnects the COM port. When it goes
off, a connected modem will disconnect. The state
of the TR LED matches that of the DTR circuit on
pin 20 of the RS-232C/V.24 interface.

• EC: Error Correction (V.42). The EC LED lights
continuously when the modem is in error-

40

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

correction mode, and blinks when compression is
activated.

• FX: Fax. The FX LED lights when the modem is in
fax mode.

NOTE

When you turn on the Mini-Modem, the speed lights flash
briefly as the modem does a self-test, then the LED for the
default modem baud rate lights. The default rate for the
Mini-Modem is 33,600 bps unless you select and store
another baud rate. After a call, the LEDs for the
connection’s baud rate remain lit until another call is made
or the modem is reset. If you connect at a rate under 9600
bps, all speed LEDs remain off after the connection is
broken, even though the modem is still turned on.

4.5 Speed Indicator Blink Rates

The 33, 14, and 96 speed indicators light singly or in
combination to indicate data rates. Data rates for the
Mini-Modem are shown in the following table.

41

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Mini-Modem Data Rates.

Data Rate (bps) 33 LED 14 LED 96 LED

<9.6K

9.6K

12.0K

14.4K

16.8K (V.32terbo)

19.2K (V.32terbo)

16.8K (V.34)

19.2K (V.34)

21.6K

24.0K

26.4K

28.8K

31.2K

33.6K
Off Slow blink (1/sec.)

On Fast blink (5/sec.)

42

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

5. AT Commands, S-Registers,
and Result Codes

5.1 AT Commands

This section summarizes your modem’s AT commands.

Command: AT Attention Code

Values: n/a
Description: The attention code precedes all

command lines except A/, A:,
and escape codes.

Command: RETURN Key

Values: n/a
Description: Press the RETURN (ENTER) key

to execute most commands.

Command: A Force Answer Mode

Values: n/a
Description: Answer call before final ring.

Command: A/ Repeat Last Command

Values: n/a
Description: Do not precede this command

43

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

with AT. Do not press RETURN
to execute.

Command: A: Continuous Redial

Values: n/a
Description: Redial last number until

answered. Do not precede this
command with AT or press
RETURN to execute.

Command: &An Answerback

Values: n = 0 or 1
Default: 0
Description: &A0 Disables answerback.

&A1 Enables answerback reply to an ID

request.

Command: $An Auto-Reliable Buffering

Values: n = 0 or 1
Default: 0
Description: $A0 Discard data received during

establishment of a reliable
connection.

44

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

$A1 Buffer data received during

establishment of a reliable
connection.

Command: #An Auto Speed Detection in Answer

Mode

Values: n = 0–3
Default: 0
Description: #A0 Start at maximum speed and fall

back to a lower speed (26400,
24000, 21600, 19200, 16800,
14400, 12000, 9600, 7200, 4800,
2400, 1200, or 300 bps) as line

conditions warrant.
#A1 Maximum speed only.
#A2 Start at maximum speed and fall

back decrementally to 4800 bps

only.
#A3 Start at 2400 bps and fall back

to 1200 to 300 bps only.

Command: Bn Answer Tone

Values: n = 1
Default: 1

45

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Description: B1 Select Bell answer tones, including

Bell 103.

Command: &BSn Maximum Reliable Block Size

Values: n = 0 or 1
Default: 1
Description: &BS0 Maximum transmit block size

of 64 characters.
&BS1 Maximum transmit block size

of 256 characters.

Command: $BAn Baud Adjust

Values: n = 0 or 1
Default: 0
Description: $BA0 Set baud adjust off, speed

conversion on. (Serial-port speed

is independent of modem data

rate.)
$BA1 Set baud adjust on, speed

conversion off. (Serial-port speed

is same as modem data rate.)

Command: &Cn Carrier-Detect Control

Values: n = 0, 1, 2, or 4
Default: 1

46

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Description: &C0 Force Carrier Detect high.

&C1 Let Carrier Detect follow carrier

signal.
&C2 Let Carrier Detect drop on

disconnect, then go high again

(for some CBX phone systems).
&C4 Reset modem when Carrier Detect

drops.

Command: &CDn Cleardown at Disconnect

Values: n = 0, 1
Default: 0
Description: &CD0 Execute a cleardown at

disconnect.
&CD1 Do not execute a cleardown at

disconnect.

Command: Ds Dial

Values: s = dial string (phone number and dial

modifiers)

Default: none
Description: Dial telephone number s, where s

may include up to 60 digits and T,

P, R, comma, colon, and

semicolon characters.

47

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Command: DsNd Store Telephone Number

Values: s = dial string (phone number and dial

modifiers)

d = 0 or 1

Default: none
Description: To store, enter D followed by dial

string s, then N followed by

directory number d.

Example: ATDT9,5551212N1.

Command: &Dn Data Terminal Ready Control

Values: n = 0–3
Default: 2
Description: &D0 Modem ignores DTR signal.

&D1 When DTR drops, the modem

hangs up. While DTR is low, the

modem accepts commands but

will not dial or auto-answer until

DTR goes high again.
&D2 Same as &D1.
&D3 When DTR drops, the modem

hangs up and resets as if an ATZ

command were issued.

48

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Command: $Dn DTR Dialing

Values: n = 0 or 1
Default: 0
Description: $D0 Do not dial when DTR goes high.

$D1 Dial stored number N0 when DTR

goes high.

Command: %DCn AT Command Control

Values: n = 0 or 1
Default: 0
Description: %DC0 The modem responds to AT

commands.
%DC1 The modem ignores AT

commands.

NOTE

The modem will respond to AT%DC for 10 seconds after powerup.

Command: %DFn Format Line Probe Data

Values: n = 0 or 1
Default: 0
Description: %DF0 Display data in graph format. Y

axis is gain shown in dBm.
%DF1 Display data in table format. Gain

is shown numerically in dBm at

49

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

75Hz increments from 150Hz to

3750Hz.

Command: %DPn Read Line Probe Data

Values: n = 0 or 1
Default: 0
Description: %DP0 Do not read and store line probe

information from DSP during

handshake.
%DP1 Read and store line probe

information from DSP during

handshake.

Command: >DTn DTMF Detection

Values: n = 0 or 1
Default: 0
Description: >DT0 The modem will not detect DTMF

tones.
>DT1 The modem will detect and report

DTMF tones when it is off-hook.

Command: En Echo Command-Mode Characters

Values: n = 0 or 1
Default: 1

50

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Description: E0 Do not echo keyboard input to

the terminal.
E1 Do echo keyboard input to the

terminal.

Command: &En V.42 Error-Correction Modes

Values: n = 0, 1, or 2
Default: 1
Description: &E0 V.42 non-error-correction mode

(V.42 disabled).
&E1 V.42 auto-reliable mode.
&E2 V.42 reliable mode (V.42

enabled).

Command: &En Modem-Initiated Flow Control

Values: n = 3, 4, or 5
Defaults: 4
Description: &E3 Flow control disabled.

&E4 CTS/RTS hardware flow control.
&E5 XON/XOFF software flow

control.

Command: &En XON/XOFF Pass-Through

Values: n = 6 or 7
Defaults: 6

51

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Description: &E6 Respond to and discard

XON/XOFF characters when &E5

is selected.
&E7 Respond to and pass through

XON/XOFF characters when &E5

is selected.

Command: &En Hewlett-Packard ENQ/ACK

Pacing

Values: n = 8 or 9
Default: 8
Description: &E8 Ignore ENQ/ACK pacing

characters.
&E9 Respond to ENQ/ACK pacing

characters.

Command: &En Non-Error-Correction Mode Flow

Control

Values: n = 10 or 11
Default: 10
Description: &E10 Disable non-error-correction

mode flow control.
&E11 Enable non-error-correction

mode flow control.

52

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Command: &En Pacing (Computer-Initiated Flow

Control)

Values: n = 12 or 13
Default: 13
Description: &E12 Pacing disabled.

&E13 Pacing enabled.

Command: &En Data Compression

Values: n = 14 or 15
Default: 15
Description: &E14 Data compression disabled.

&E15 Data compression enabled.

Command: $En V.42 Error Correction at 300 bps

Values: n = 0 or 1
Default: 0
Description: $E0 V.42 error correction at 300 bps

disabled.
$E1 V.42 error correction at 300 bps

enabled.

Command: $EBn Asynchronous Word Length

Values: n = 0 or 1
Default: 0
Description: $EB0 10-bit mode enabled.

53

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

$EB1 11-bit mode enabled.

Command: %En Escape Sequence Options

Values: n = 0–5
Defaults: 1 and 4
Description: %E0 Modem won’t escape.

%E1 +++AT<CR> method.
%E2 <BREAK>AT<CR> method.
%E3 Both +++AT<CR> and

<BREAK>AT<CR> methods.
%E4 No OK response to +++AT<CR>.
%E5 OK response to +++AT<CR>.

Command: &Fn Load Default Configurations

Values: n = 0, 8, or 9
Default: 8
Description: &F0 Load factory-default values from

ROM if &F8 was previously stored;

load user default values from non-

volatile memory if &F9 was

previously stored.
&F8 Read factory-default values when

&F is issued (effective only if you

store &F8 using &W0).

54

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

&F9 Read values stored in non-volatile

memory when &F is issued

(effective only if you store &F9

using &W0).

Command: $Fn Enable/Disable Auto-Reliable

Fallback Character

Values: n = 0 or 1
Default: 0
Description: $F0 Do not fall back to non-error-

correction mode connect if <CR>

is received during handshake.
$F1 Fall back to non-error-correction

mode connect if <CR> is received

during handshake.

Command: %Fn Echo-Canceller Frequency-Offset

Compensation

Values: n = 0 or 1
Default: 0
Description: %F0 Disable echo-canceller frequency-

offset compensation.
%F1 Enable echo-canceller frequency-

offset compensation.

55

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Command: #Fn Fallback Modes When On Line

Values: n = 0, 1, or 2
Default: 2
Description: #F0 No fallback when on line.

#F1 Fall back decrementally from

maximum speed to 4800 bps as

line conditions deteriorate.
#F2 Fall back decrementally to 4800

bps; fall forward when line

conditions improve.

Command: &Gn Guard Tones

Values: n = 0, 1, or 2
Default: 0
Description: &G0 Turn off ITU-T guard tones.

&G1 Turn on ITU-T 550-Hz guard

tone.
&G2 Turn on ITU-T 1800-Hz guard

tone.

Command: Hn On Hook/Off Hook

Values: n = 0 or 1
Default: None
Description: H0 Go on hook (hang up).

H1 Go off hook.

56

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Command: $Hn Help Screens

Values: n = 1, 2, or 3
Default: None
Description: $H1 Display Help Screen #1.

$H2 Display Help Screen #2.
$H3 Display Help Screen #3.

Command: In Inquire Product Codes

Values: n = 0, 1, or 2
Default: None
Description: I0 Display modem ID number.

I1 Display firmware version number.
I2 Display modem description.

Command: #Ix Enter Login Password

Values: x = password (6 to 10 characters)
Default: MULTI-TECH
Description: Enters the remote-configuration

login password.

Command: #I=x Store Login Password

Values: x = password (6–10 characters)
Default: MULTI-TECH

57

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Description: Stores a new remote-configuration

login password.

Command: Ln List Commands

Values: n = 0, 5–8
Default: None
Description: L List stored telephone numbers.

L5 List current operating parameters.
L6 List current S-register values.
L7 List additional current operating

parameters.
L8 List DSP code version number,

processor speed, and online

diagnostic parameters.
L9 List signal-strength information.
L10 List signal-to-noise ratio

information (SNR).
L11 List noise information.

Note: For L9, L10, and L11, you

must first type +++AT<CR> (on-

line escape command while

maintaining command mode),

then type the command prefixed

by an AT (e.g., ATL10).

58

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Command: #Ln V.42 Mode Selection in Originate

Mode

Values: n = 0, 1, 2, or 3
Default: 0
Description: #L0 Modems negotiate V.42 mode.

#L1 MNP on & LAP-M off.
#L2 LAP-M on & MNP off.
#L3 Disable detection phase and go

directly to LAP-M.

Command: Mn Modem Speaker Control

Values: n = 0, 1, 2, or 3
Default: 1
Description: M0 Speaker always off.

M1 Speaker on until carrier signal

detected.
M2 Speaker always on.
M3 Speaker on during dialing, off

during handshaking.

Command: $MBn Modem Baud Rate

Values: n = speed
Default: 33600
Description: $MB75 Originate call in ITU-T V.23 mode

$MB300 Originate call at 300 bps.

59

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

$MB1200 Originate call at 1200 bps.
$MB2400 Originate call at 2400 bps.
$MB4800 Originate call at 4800 bps.
$MB7200 Originate call at 7200 bps.
$MB9600 Originate call at 9600 bps.
$MB14400 Originate call at 14,400 bps.
$MB16800 Originate call at 16, 800 bps.
$MB19200 Originate call at 19,200 bps.
$MB28800 Originate call at 28,800 bps.
$MB33600 Originate call at 33,600 bps.

Command: Nd Dial a Stored Number

Values: d = 0 or 1
Default: None
Description: Dial stored telephone number d.

Command: NdNe... Number Linking

Values: d = 0 or 1; e = 1 or 0
Default: None
Description: Dial stored number d; if it is busy,

dial stored number e.

Command: O Go Back On Line

Values: n/a

60

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Description: Return to online mode after you

have used an escape sequence to

go from online mode to

command mode.

Command: P Pulse Dial

Values: n/a
Default: Yes
Description: The modem pulse-dials numbers

that follow P in the dialing

command.

Command: &Pn Set Pulse-Dial Ratios

Values: n = 0 or 1
Default: 0
Description: &P0 60:40 break/make pulse ratio.

&P1 67:33 break/make pulse ratio.

Command: Qn Result Codes Enable/Disable

Values: n = 0, 1, or 2
Default: 0
Description: Q0 Enable result codes.

Q1 Disable result codes (quiet).
Q2 Enable no-response answer mode,

which leaves originate mode

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

intelligent while turning off

answer-mode responses and echo.

Command: &Qn Multi-Tech or Standard Result

Codes

Values: n = 0 or 1
Default: 0
Description: &Q0 Multi-Tech responses with

modifiers.
&Q1 Standard AT responses with no

modifiers.

Command: Rn Reverse Originate/Answer Modes

Values: n = 0 or 1
Default: 0
Description: R0 Modem will not reverse modes.

R1 Modem will reverse modes when

R is added to the dial string.

Command: &Rn Clear to Send Control

Values: n = 0, 1, or 2
Default: 1
Description: &R0 Let CTS state follow RTS state

when on line.
&R1 Force CTS high (on).

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

&R2 Let CTS drop on disconnect for

time set by S24, then go high

again.

Command: &RAn Asymmetrical Bit Rate

Values: n = 0 or 1
Default: 0
Description: &RA0 Enable asymmetrical bit rate in

V.34 mode.
&RA1 Disable asymmetrical bit rate in

V.34 mode.

Command: &RDn Square-Wave Ring Detect

Values: n = 0 or 1
Default: 1
Description: &RD0 Modem detects only sine-wave

rings.
&RD1 Modem detects both sine- and

square-wave rings.

Command: &RFn CTS/RTS Interaction Control

Values: n = 0 or 1
Default: 1
Description: &RF0 Let CTS follow RTS.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

&RF1 Let CTS act independently (use

with &R).

Command: &RN Rate Negotiation

Values: n/a
Description: Forces the modem to perform a

rate renegotiation while on line.

You must escape to command

mode to issue this command.

Command: &RP Immediate Line Probe

Values: n/a
Description: Initiates a retrain that makes the

processor read line-probe

information if %DP1 is selected.

Valid only when on line in V.34

mode.

Command: &RR Immediate Retrain

Values: n/a
Description: Forces the modem to perform an

immediate retrain while on line.

You must escape to command

mode to issue this command.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Command: $Rn Retransmit Count

Values: n = 0 or 1
Default: 0
Description: $R0 Disconnect after 50 retransmits of

a data block.
$R1 Do not disconnect after 50

retransmits.

Command: Sr=n Set Register Value

Values: r = S-register number; n varies
Default: None
Description: Set value of register Sr to value of

n, where n is entered in decimal

format.

Command: Sr? Read Register Value

Values: r = S-register number
Default: None
Description: Read value of register Sr and

display value in 3-digit decimal

form.

Command: &Sn Data Set Ready Control

Values: n = 0, 1, or 2
Default: 1

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Description: &S0 Force DSR high (on).

&S1 Let DSR follow CD.
&S2 DSR drops on disconnect, then

goes high again. (Used by some

CBX phone systems.)

Command: &SFn DSR/CD Interaction Control

Values: n = 0 or 1
Default: 0
Description: &SF0 Select DSR to follow CD.

&SF1 Select DSR to be independent.

Command: $SBn Serial-Port Baud Rate

Values: n = speed
Default: 57600
Description: $SB300 Set serial port to 300 bps.

$SB1200 Set serial port to 1200 bps.
$SB2400 Set serial port to 2400 bps.
$SB4800 Set serial port to 4800 bps.
$SB9600 Set serial port to 9600 bps.
$SB19200 Set serial port to 19200 bps.
$SB38400 Set serial port to 38400 bps.
$SB57600 Set serial port to 57600 bps.
$SB115200 Set serial port to 115200 bps.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

NOTE: Baud adjust must be off ($BA0) to

enable fixed baud rate.

Command: #Sy Enter Setup Password

Values: y= password (6–10 characters)
Default: MODEMSETUP
Description: Enters the remote configuration

setup password.

Command: #S=y Store Setup Password

Values: y= password (6–10 characters)
Default: MODEMSETUP
Description: Stores a new remote configuration

setup password.

Command: T Tone-Dial

Values: n/a
Default: P command
Description: Modem will tone-dial numbers

following a T in the dialing

command.

Command: &Tn Respond to Remote Digital

Loopback Signal

Values: n = 4 or 5

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Default: 5
Description: &T4 Enable response to remote digital

loopback signal.
&T5 Disable response to remote digital

loopback signal.

Command: #Tn Trellis-Coded Modulation

Values: n = 0 or 1
Default: 1
Description: #T0 Disable trellis-coded modulation.

#T1 Enable trellis-coded modulation.

Command: Un Loopback Test Modes

Values: n = 0, 1, 2, or 3
Default: None
Description: U0 Enable local analog loopback

originate mode.
U1 Enable local analog loopback

answer mode.
U2 Enable remote digital loopback

mode.
U3 Enable local digital loopback

mode.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Command: Vn Result Codes (Verbose/Terse)

Values: n = 0 or 1
Default: 1
Description: V0 Result codes sent as digits (terse

response).
V1 Result codes sent as words

(verbose response).

Command: #Vn V.32terbo Handshake Tones

Values: n = 0 or 1
Default: 1
Description: #V0 Include V.32terbo tones in

handshake.
#V1 Exclude V.32terbo tones from

handshake.

Command: W Wait for New Dial Tone

Values: n/a
Description: Inserted in dialing command,

causes modem to wait for a new

dial tone. (X2 or X4 must be

selected.)

Command: &Wn Store Configuration

Values: n = 0 or 1

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Default: 1
Description: &W0 Store current settings in NVRAM;

load them at power-on or

following the ATZ command

instead of loading the factory

defaults from ROM.
&W1 Clear user default settings from

NVRAM.

Command: Xn Result Codes and Call-Progress

Selection

Values: n = 0–4
Default: 0
Description: X0 Basic result codes (CONNECT

only); does not look for dial tone

or busy signal.
X1 Extended result codes

(CONNECT 28800, CONNECT

33600, etc.); does not look for dial

tone or busy signal.
X2 Extended result codes with NO

DIALTONE; does not look for

busy signal.
X3 Extended result codes with BUSY;

does not look for dial tone.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

X4 Extended result codes with NO

DIALTONE and BUSY.

Command: #Xn Number of XOFF Characters Sent

Values: n = 0 or 1
Default: 0
Description: #X0 Single XOFF character sent after

buffer is full.
#X1 Multiple XOFF characters sent

(one for every character received

after buffer is full).

Command: Yn Long Space Disconnect

Values: n = 0 or 1
Default: 0
Description: Y0 Disable sending or responding to

long-space break signal on

disconnect.
Y1 Enable sending or responding

to long-space break signal on

disconnect. (Both modems must

have Y1 set.)

Command: Z Modem Reset

Values: n/a

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Description: Reset modem to default values.

Defaults come from user NVRAM

if &W0 is set, from factory ROM if

&W1 is set.

Command: , Dialing Pause

Values: n/a
Description: Placed in dialing command,

comma causes dialing pause

for time set by S8.

Command: : Continuous Redial

Values: n/a
Description: Placed at end of dial command,

a colon causes continuous redial

of a number until answered.

Command: ; Return to Command Mode

Values: n/a
Description: Placed at end of dial command,

a semicolon causes an immediate
return to command mode after
dialing.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Command: ! Flash On-Hook

Values: n/a
Description: Placed in dial command,

exclamation point causes
modem to flash on-hook.

Command: @ Quiet Answer

Values: n/a
Description: Placed in dial command, @ causes

modem to wait for a ringback,
then 5 seconds of silence, before
processing next part of command.

Command: $ Call-Card Tone Detect

Values: n/a
Description: Placed in dial command, causes

modem to wait for a call-card tone
before processing next part of
command (such as a call-card
number).

Command: %%%AT<CR> Remote-Configuration

Escape Sequence

Values: n/a

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Description: Initiates remote-configuration

mode while online with remote
modem. The remote­configuration escape character
(%) is defined in register S13.

Command: +++AT<CR> Escape Code

Values: n/a
Description: Puts modem in command mode

(and optionally issues a
command) while remaining on
line. Enter +++AT, up to ten
command characters (or as
defined by S34), and a RETURN.
Used mostly to issue hang-up
command: +++ATH<CR>.

Command: <BREAK>AT<CR> Escape Sequence

Values: n/a
Description: Alternate escape method. Puts

modem in command mode while
remaining on line. Send a
<BREAK> signal followed by
AT, then up to sixty command
characters, and a RETURN. You

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

must set the modem to %E2 or
%E3 before you can use this
escape method.

4.2 S-Registers

Certain modem values, or parameters, are stored in
memory locations called S-registers. Use the S command
to read or to alter the contents of S-registers (see
previous section).

Register Unit Range Default Description

S0 1 ring 0, 1–255 1 Sets the number of rings until the

modem answers. ATS0=0
disables autoanswer completely.

S1 1 ring 0–255 0 Counts the rings that have

occurred.

S2 decimal 0–127 43 (+) Sets ASCII code for the escape-

code character.

S3 decimal 0–127 13 (^M) Sets ASCII code for the RETURN

character.

S4 decimal 0–127 10 (^J) Sets ASCII code for the LINE

FEED character.

S5 decimal 0–127 8 (^H) Sets ASCII code for the

BACKSPACE character.

S6 1 sec. 2–255 2 Sets the time the modem

4–255 4 will wait for a dial tone before

aborting a call.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Register Unit Range Default Description

S7 1 sec. 1–255 45 Sets the time the modem

1–45 45 will wait for a carrier signal before

aborting a call.

S8 1 sec. 0–255 2 Sets the length of a pause

4–255 4 caused by a comma character in

a dialing command.

S9 100 ms 1–255 6 Sets delay between when the

modem detects a valid carrier
signal and when it turns on its CD
circuit.

S10 100 ms 1–254, 7 Sets how long a carrier

255 signal must be lost before the

modem disconnects. S10=255
causes the modem to not
disconnect with loss of carrier.

S11 1 ms 1–255 70 Sets spacing and duration

80–255 80 of dialing tones. 50 ms is the

recommended minimum.

S13 decimal 0, 1–127 37 (%) Sets ASCII code for remote

configuration escape character.
S13=0 disables remote
configuration.

S17 10 ms 1–255 25 Sets the length of the break time

(space) sent to the local PC when
the modem receives a remote
break.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Register Unit Range Default Description

S24 50 ms 0–255 20 Sets the time the DSR, CTS, and

CD signals drop before going
high again. Used for some PBX
and CBX phone systems.

S25 100 ms 0, 1–255 0 Sets the time the DTR signal

must be dropped before the
modem disconnects. The 0
default equals 50 ms.

S30 1 min. 0, 1–255 0 Sets how long the modem waits

after the last character is received
or transmitted before it
disconnects. The 0 default
disables the timer.

S32 100 ms 0–255 20 Sets the time the modem will wait

for a RETURN to be entered
during escape-sequence
execution.

S34 1 char- 0–60 10 Sets the number of com-

acter mand characters allowed

after +++AT.

S36 1 sec. 0, 1-255 5 Sets the time between DTR

inactive and modem off-hook.
S36=0 disables DTR busy-out.

S37 1 sec. 0-255 5 Sets the time between DTR

active and modem on-hook.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Register Unit Range Default Description

S43 decimal 28, 26, 0 Sets fixed V.34 connect

24, 21, speed. 28 = 28800 bps;
19, 16, 26 = 26400 bps;. . . 48 =
14, 12, 4800 bps. 0 default disables
96, or 48 this feature.

S48 decimal 33, 31, 0 Sets maximum V.34 connect

28, 26, speed. 33 = 33600 bps;
24, 21, 31 = 31200 bps;. . . 48 =
19, 16, 4800 bps. 0 default disables
14, 12, feature (same as S48=33).
96, or 48

4.3 Result Codes

In command mode the Mini-Modem can send
responses, or result codes, to your computer. Result
codes are used by communications programs and can
also appear on your monitor.

AT&Q0 selects result codes with RELIABLE, LAPM, and
COMPRESSED modifiers (default).

AT&Q1 selects standard AT result codes without
modifiers.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

&Q0 Mini-Modem Result Codes &Q1 Standard AT Result Codes

Terse Verbose Terse Verbose
0OK 0 OK
1 CONNECT 1 CONNECT
2 RING 2 RING
3 NO CARRIER 3 NO CARRIER
4 ERROR 4 ERROR
5 *CONNECT 1200 5 CONNECT 1200
6 NO DIALTONE 6 NO DIAL TONE
7 BUSY 7 BUSY
8 NO ANSWER 8 NO ANSWER
9 CONNECT 2400

10 CONNECT 2400
11 *CONNECT 4800 11 CONNECT 4800
12 *CONNECT 9600 12 CONNECT 9600
13 *CONNECT 14400 13 CONNECT 14400
19 *CONNECT 19200 19 CONNECT 19200
21 *CONNECT 21600 21 CONNECT 21600
24 *CONNECT 24000 24 CONNECT 24000
26 *CONNECT 26400 26 CONNECT 26400
28 *CONNECT 28800 28 CONNECT 28800
31 *CONNECT 31200 31 CONNECT 31200
33 *CONNECT 33600 33 CONNECT 33600

* With error correction on, RELIABLE (or R) or LAPM (or L) is added to these result
codes. With data compression on, COMPRESSED (or C) is added.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

6. Troubleshooting

6.1 Introduction

Your Mini-Modem was thoroughly tested at the factory
before it was shipped. If you are unable to make a
successful connection, or if you experience data loss or
garbled characters during your connection, it is possible
that the modem is defective. However, it is more likely
that the source of your problem lies elsewhere. The
following symptoms are typical of problems you may
encounter:

• None of the LEDs light when the modem is on.

• The modem does not respond to commands.

• The modem dials but is unable to make a
connection.

• The modem disconnects while online.

• The modem cannot connect when answering.

• File transfer is slower than it should be.

• You are losing data.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

• You are getting garbage characters on the
monitor.

• You can’t run your fax and communications
software at the same time.

If you experience problems, please check the
following possibilities before calling Tech Support
(see Appendix B).

6.2 None of the LEDs Light When the Modem Is On

When you turn on the Mini-Modem, the LED indicators
on the front panel should flash briefly as the modem
runs a self-test. If the LEDs remain off, the modem is
probably not receiving power.

• Make sure the modem’s power switch is on,
especially if you normally turn on the modem by
turning on a power strip.

• If the power supply is plugged into a power strip,
make sure the power strip is plugged in and its
power switch is on.

• Make sure the power-supply module is firmly
connected to the modem and to the wall outlet or
power strip.

81

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

• If the power strip is on and the modem switch
is on, try moving the modem power supply to
another outlet on the power strip.

• Test that the outlet is live by plugging a lamp
into it.

• The modem or power supply may be defective. If
you have another modem, try swapping modems.
If the problem goes away, the first modem or
power supply may be defective. Call Tech Support
for assistance.

CAUTION

Do not under any circumstances replace the power-supply
module with one designed for another product, as it may
damage the modem.

6.3 The Modem Does Not Respond to Commands

• Make sure the modem is plugged in and turned
on. (See Section 6.2.)

• Make sure you are issuing the modem commands
from the data-communications software, either
manually in terminal mode (you cannot send
commands to the modem from the DOS prompt).

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

• Make sure you are in terminal mode in your data
comm software. Type AT and press ENTER. If you
get an OK response, your connections are good
and the problem likely is in your phonebook entry
or session settings.

• Try resetting your modem by turning it off and on.
Make sure there is a reset command (&F) in your
initialization string, or your modem may not
initialize correctly.

• If you don’t get an OK, the problem may still be
in the communications software. Make sure you
have done whatever is necessary in your software
to make a port connection. Not all communi­cations programs connect to the COM port
automatically. Some connect when the software
loads and remain connected until the program
terminates. Others can disconnect without exiting
the program or allow multiple terminals to be
open, but only one can access the modem at a
time. If the terminal reports that it cannot make
a connection, yet the modem’s TR indicator is on,
click on the Window menu to see if more than
one terminal is open. The modem’s TR indicator
shows that the software has made a connection
with the modem through the COM port.

83

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

• Your communications-software settings may not
match the physical port the modem is connected
to. The serial cable may be plugged into the wrong
connector—check your computer documentation
to make sure. Or you may have selected a COM
port in your software other than the one the
modem is physically connected to—compare the
settings in your software to the physical
connection.

• If the modem is on, the cable is plugged into the
correct port, the communications software is
configured correctly, and you still don’t get an
OK, the fault may be in the serial cable. Make sure
it is firmly connected at both ends.

• Is this the first time you have used the cable? If so,
it may not be correct. Check the cable description
on the packaging to make sure the cable is the
right one for your computer.

• Peripheral expansion cards, such as bus-mouse
and sound cards, may include a serial port
preconfigured as COM1 or COM2. The extra
serial port, or the card itself, may use the same
COM port, memory address, or interrupt request
(IRQ) as your communications port. Be sure to
disable any unused ports.

84

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

To look for address or IRQ conflicts if you use
Windows 3.1x, select File, Run in Program Manager,
type MSD, and press ENTER. Then select Mouse, COM
Ports, and IRQ Status and note the addresses and IRQs
that are in use. If you find an IRQ conflict, note which
IRQs are not being used, then change one of the
conflicting devices to use one of the unused IRQs. If you
find an address conflict, change the address of one of
the conflicting devices.

To change a port address or IRQ in Windows 3.1x,
double-click the Control Panel icon, then the Ports icon.
Click on the port you want to change, click Settings,
click Advanced, and select the new port address and/or
interrupt. If you wish to use COM3 or COM4, note that
COM3 shares an IRQ with COM1, as does COM4 with
COM2, so you should change their IRQs to unused
ones, if possible.

If you use Windows 95 or 98, right-click on My
Computer, select Properties from the menu, click on the
Device Manager tab, double-click on Ports, then double­click on the Communications Port your modem is
connected to. In the port’s Properties sheet, click on the
Resources tab to see the port’s Input/Output range and

85

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Interrupt Request. If another device is using the same
address range or IRQ, it will appear in the Conflicting
Device List. Uncheck Use Automatic Settings to change
the port’s settings so they do not conflict with the other
device, or select the port the conflicting device is on and
change it instead. If you need to open your computer to
change switches or jumpers on the conflicting device;
refer to the device’s documentation.

• The serial port may be defective. If you have
another serial port, install the modem on it,
change the COM-port setting in your software,
and try again.

• The modem may be defective. If you have another
identical modem, try swapping modems. If the
problem goes away, the first modem is possibly
defective. Call Tech Support for assistance (see
Appendix B).

6.4 The Modem Dials But Cannot Make a Connection

There can be several reasons the Mini-Modem fails to
make a connection:

• lack of a physical connection to the telephone line

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

• a wrong dial tone.

• a busy signal.

• a wrong number.

• no modem at the other end.

• a faulty modem, computer, or software at the
other end.

• incompatibility between modems.

You can narrow the list of possibilities by using
extended result codes. To enable them, enter ATV1X4
and press ENTER while in terminal mode, or include
V1X4 in the modem’s initialization string.

• If the modem reports NO DIALTONE, check that
the modem’s telephone line cable is connected to
both the modem’s LINE jack (not the PHONE
jack) and the telephone wall jack. If the cable
looks secure, try replacing it. If that doesn’t work,
the problem may be in your building’s telephone
installation. To test the building installation, plug
a telephone into your modem’s telephone jack
and listen for a dial tone. If you hear a dial tone,
your modem may be installed behind a company

87

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

phone system (PBX) with an internal dial tone
that sounds different from the normal dial tone.
In that case, the modem may not recognize the
dial tone and may treat it as an error. Make sure
your modem’s square wave ring detection is
turned on (&RD1). Check your PBX manual to
see if you can change the internal dial tone; if you
can’t, change your modem’s initialization string to
replace X4 with X3, which will cause the modem
to ignore dial tones (note, however, that X3 is not
allowed in some countries, such as France and
Spain).

• If the modem reports BUSY, the other number
may be busy, in which case you should try again
later, or it may indicate that you have failed to add
a 9, prefix to the phone number if you must dial 9
for an outside line.

• If you must dial 9 to get an outside line, the easiest
way to dial it automatically is to include it in the
modem’s dial prefix—for example, ATDT9,. Note
the comma, which inserts a pause before the
number is dialed. By inserting 9 and a comma into
the dial prefix, you do not have to include it in
each directory entry.

88

MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

To change the dial prefix in Windows Terminal,
select Settings, Modem Commands. To change it
in Windows 95 or 98 HyperTerminal, select Call,
Connect from the menu bar, click Dialing
Properties, and type 9 in the local and long­distance boxes in How I Dial from This Location.

• If the modem reports NO ANSWER, the other
system has failed to go off-hook, or you might have
dialed a wrong number. Check the number.

• If the modem reports NO CARRIER, the phone
was answered at the other end, but no connection
was made. You might have dialed a wrong number,
and a person answered instead of a computer, or
you might have dialed the correct number but the
other computer or software was turned off or
faulty. Check the number and try again, or try
calling another system to make sure your modem
is working. Also, try calling the number on your
telephone. If you hear harsh sounds, then another
modem is answering the call, and the modems
may be having problems negotiating because of
modem incompatibilities or line noise. Try
connecting at a lower speed.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

6.5 The Modem Disconnects While Online

• If you have call waiting on the same phone line

as your modem, it may interrupt your connection
when someone tries to call you. If you have call
waiting, disable it before each call. In most
telephone areas, you can disable call waiting
by preceding the telephone number with *70
(check with your local telephone company).

You can automatically disable call waiting by
including the disabling code in the modem’s dial
prefix (for example, ATDT*70,—note the comma,
which inserts a pause before the number is
dialed). To change the dial prefix in Windows
Terminal, select Settings, Modem Commands. To
change it in Windows 95 or 98 HyperTerminal,
select Call, Connect from the menu bar, click
Dialing Properties, check This Location Has Call
Waiting, and select the correct code for your
phone service.

• If you have extension phones on the same line as
your modem, you or someone else can interrupt
the connection by picking up another phone. If
this is a frequent problem, disconnect the exten­sion phones before using the modem, or install
another phone line especially for the modem. Or

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

you can install a device that prevents extensions
from accidentally interrupting your transmission—
for example, The Eliminator (product code
FA100).

• Check for loose connections between the modem
and the computer, the telephone jack, and AC
power.

• You may have had a poor connection because of
line conditions, or the problem may have
originated on the other end of the line. Try again.

• If you were online with a BBS, it may have hung
up on you because of lack of activity on your part
or because you exceeded your time limit for the
day. Try again.

6.6 The Modem Cannot Connect When Answering

• Auto-answer may be disabled. Turn on auto­answer in your datacomm program or send the
command ATS0=1 to your modem in terminal
mode.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

6.7 File Transfer Is Slower Than It Should Be

• You may have an older UART. For best
throughput, install a 16550AFN UART or an ISI
serial port card. See the “Quick Start” chapter for
information on how to identify your UART.

• If you are running under Windows 3.1 and have a
16550AFN UART, you must replace the Windows
serial driver, COMM.DRV, to take full advantage
of the UART’s speed.

• If you are using a slow transfer protocol, such as
Xmodem or Kermit, try Zmodem or Ymodem/G
instead.

• Is your line noisy? If there is static on your line,
the modem has to resend many blocks of data to
insure accuracy. You must have a clean line for
maximum speed.

• Are you downloading a compressed file with
MNP 5 hardware compression enabled? Since
hardware data compression cannot compress a file
already compressed by an archiving program, the
transfer can be marginally slower with data
compression enabled than with it disabled.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

• Try entering the L8 (List Online Diagnostics)
command in online mode, making a screen print
of the diagnostics listing, and checking for
parameters that may be unacceptable (number
of retrains, round-trip delay, etc.).

6.8 I Am Losing Data

• If you are using data compression and a high
speed serial port, set the serial port baud rate
to four times the data rate.

• Your UART may not be reliable at serial port
speeds over 9600 bps or 19,200 bps. Turn off
data compression, reset your serial-port speed
to a lower rate, or replace your serial port with
a faster one.

• Make sure the flow-control method you selected in
software matches the method selected in the
modem.

• If you are running under Windows 3.1 and have
a 16550AFN UART, you may need to turn on the
16550’s data buffers and/or replace the Windows
serial driver, COMM.DRV.

• Try entering the L8 (List Online Diagnostics)

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

command in online mode, making a screen print
of the diagnostics listing, and checking for para­meters that may be unacceptable (number
of retrains, round trip delay, etc.).

6.9 I Am Getting Garbage Characters on the Monitor

• Your computer and the remote computer may be
set to different word lengths, stop bits, or parities.
If you have connected at 8-N-1, try changing to
7-E-1, or vice-versa, using your communications
software.

• You may be experiencing line noise. Enable error
correction, if it is disabled, or hang up and call
again; you may get a better connection.

• At speeds above 2400 bps, the remote modem
might not use the same transmission or error
correction standards as your modem. Try
connecting at a slower speed or disabling error
correction. (With no error correction, however,
line noise can cause garbage characters.)

• Try entering the L8 (List Online Diagnostics)
command in online mode, making a screen print
of the diagnostics listing, and checking for para­meters that may be unacceptable (number of
retrains, round trip delay, etc.).

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

6.10 My Fax and Communications Software Won’t Run at the
Same Time

Communications devices can be accessed by only one
application at a time. Under DOS or Windows 3.1x, you
can run either your fax software or your datacomm
software, but not both at the same time. In Windows 95
or 98, you can have data and fax communication
applications open at the same time, but they cannot
use the same modem at the same time.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Appendix A: Regulatory

Information

A.1 Single-User Software License Agreement

Black Box grants Customer the right to use one copy
of the software on a single computer (the Licensed
System). You may not network the software or otherwise
use it on more than one computer or computer
terminal at the same time. Customer must treat the
software like any copyrighted material. The software
may not be assigned, sublicensed, translated or
otherwise transferred by Customer.

A.2 FCC Regulations for Telephone Line Interconnection

See page 1.

Model Number: Black Box part number

MD1621A

FCC Registration Number: AU7USA-20673-MM-E

Ringer Equivalence: 0.3B

Modular Jack (USOC): RJ11C or RJ11W (single line)

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

A.3 Canadian Limitations Notice

NOTICE: The Industry Canada label identifies certified
equipment. This certification means that the equipment
meets certain telecommunications network protective,
operational and safety requirements. The Industry
Canada label does not guarantee the equipment will
operate to the user’s satisfaction.

Before installing this equipment, users should ensure
that it is permissible to be connected to the facilities of
the local telecommunications company. The equipment
must also be installed using an acceptable method of
connection. In some cases, the company’s inside wiring
associated with a single line individual service may be
extended by means of a certified connector assembly
(telephone extension cord). The customer should be
aware that compliance with the above conditions may
not prevent degradation of service in some situations.

Repairs to certified equipment should be made by an
authorized Canadian maintenance facility designated by
the supplier. Any repairs or alterations made by the user
to this equipment; or equipment malfunctions, may give
the telecommunications company cause to request the
user to disconnect the equipment.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Users should ensure for their own protection that the
electrical ground connections of the power utility,
telephone lines and internal metallic water pipe system,
if present, are connected together. This precaution may
be particularly important in rural areas.

CAUTION

Users should not attempt to make such connections
themselves, but should contact the appropriate electric
inspection authority, or electrician, as appropriate.

The Load Number (LN) assigned to each terminal
device denotes the percentage of the total load to be
connected to a telephone loop which is used by the
device, to prevent overloading. The termination on a
loop may consist of any combination of devices subject
only to the requirement that the total of the Load
Numbers of all the devices does not exceed 100. The
Load Number for this product is 3.

This digital apparatus does not exceed the Class B
limits for radio noise for digital apparatus set out in
ICES-003 of Industry Canada.

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MINI-MODEM (33.6 KBPS DATA/FAX MODEM)

Appendix B. Service and

Technical Support

B.1 Calling for Technical Support

If you have any questions about the operation of
this unit, please call Black Box Technical Support
at 724-746-5500.

B.2 About the Internet

You can also email questions to Black Box at this
address:

[e-mail]

Visit the Black Box Web site at:

http://www.blackbox.com

1000 Park Drive • Lawrence, PA 15055-1018 • 724-746-5500 • Fax [phone]

© Copyright 2001. Black Box Corporation. All rights reserved.