Paradyne KeepInTouch 3760 User manual

You have accessed an older version
of a Paradyne product document.
Paradyne is no longer a subsidiary
of AT&T. Any reference to
AT&T Paradyne is amended to
read Paradyne Corporation.
3760-A2-GB92-00
Issue 1
November 1994
Paradyne
t
KeepInTouch Card Modem
Model 3760-B2
User’s Guide
Printed on recycled paper
Important Regulatory Information
E
COPYRIGHT
1994 AT&T Paradyne
Corporation*
All Rights Reserved
Printed in U.S.A.
Notice
This publication is protected by federal copyright law. No part of
this publication may be copied or distributed, transcribed, stored
in a retrieval system, or translated into any human or computer
language in any form or by any means, electronic, mechanical,
magnetic, manual or otherwise, or disclosed to third parties
without the express written permission of AT&T Paradyne
Corporation, 8545 126th Ave. N., P.O. Box 2826, Largo, Florida
34649-2826.
AT&T Paradyne Corporation makes no representation or
warranties with respect to the contents hereof and specifically
disclaims any implied warranties of merchantability or fitness for
a particular purpose. Further, AT&T Paradyne Corporation
reserves the right to revise this publication and to make changes
from time to time in the contents hereof without obligation of
AT&T Paradyne Corporation to notify any person of such
revision or changes.
Changes and enhancements to the product and to the
information herein will be documented and issued as a new
release to this manual.
A Reader’s Comments form is provided at the front of this
publication and your comments are appreciated. If the form has
been removed, address comments to AT&T Paradyne
Corporation, Technical Publications, 8545 126th Ave. N., P.O.
Box 2826, Largo, Florida 34649-2826. AT&T Paradyne may use
or distribute any of the information supplied, as appropriate,
without incurring any obligation whatsoever.
* AT&T Paradyne is a member of AT&T’s Multimedia Products
and Services Group.
A
Issue 1 November 1994
Important Regulatory Information
Trademarks
Bell is a registered trademark of the Regional Bell Operating
Company.
KeepInTouch is a trademark of AT&T.
MNP is a registered trademark of Microcom, Inc.
PKUNZIP is a registered trademark of PKWARE, Inc.
All other product names are copyrighted and registered trademarks
of their respective owners.
Warranty
A limited warranty is provided with this product. Refer to the
enclosed Warranty Card for more information.
Important Safety Instructions
1. Read and follow all warning notices and instructions
marked on the product or included in the manual.
2. Do not attempt to service this product yourself, as opening
or removing covers may expose you to dangerous high
voltage points or other risks. Refer all servicing to qualified
service personnel.
3. General purpose cables are provided with this product.
Special cables, which may be required by the regulatory
inspection authority for the installation site, are the
responsibility of the customer.
4. When installed in the final configuration, the product must
comply with the applicable Safety Standards and
regulatory requirements of the country in which it is
installed. If necessary, consult with the appropriate
regulatory agencies and inspection authorities to ensure
compliance.
5. A rare phenomenon can create a voltage potential
between the earth grounds of two or more buildings. If
products installed in separate buildings are
interconnected, the voltage potential may cause a
hazardous condition. Consult a qualified electrical
consultant to determine whether or not this phenomenon
exists and, if necessary, implement corrective action prior
to interconnecting the products.
Issue 1 November 1994
B
Important Regulatory Information
In addition, if the equipment is to be used with
telecommunications circuits, take the following precautions:
–
–
–
–
–
–
Never install telephone wiring during a lightning storm.
Never install telephone jacks in wet locations 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 electric shock from lightning.
Do not use the telephone to report a gas leak in the
vicinity of the leak.
Government Requirements and Equipment Return
Certain governments require that instructions pertaining to
modem connection to the public switched telephone network be
included in the installation and operation manual. Specific
instructions are listed in the following sections.
United States
Notice To Users Of The Public Switched Telephone Network
1. This equipment complies with Part 68 of the FCC rules. On
the equipment is a label that contains, among other
information, the FCC registration number and ringer
equivalence number (REN) for this equipment. If requested,
this information must be provided to the telephone company.
2. The Universal Service Order Code (USOC) associated with
the services the equipment is to be connected is RJ11C.
3. The Ringer Equivalence Number (REN) is used to determine
the quantity of devices which may be connected to the
telephone line. Excessive RENs on the telephone line may
result in the devices not ringing in response to an incoming
call. In most, but not all areas, the sum of the RENs should
not exceed five (5.0). To be certain of the number of devices
that may be connected to the line, as determined by the total
RENs, contact the telephone company to determine the
maximum RENs for the calling area.
C
Issue 1 November 1994
Important Regulatory Information
4. If the modem causes harm to the telephone network, the
telephone company will notify you in advance that temporary
discontinuance of service may be required. But if advance
notice is not practical, the telephone company will notify the
customer as soon as possible. Also, you will be advised of
your right to file a complaint with the FCC if you believe it is
necessary.
5. The telephone company may make changes in its facilities,
equipment, operations, or procedures that could affect the
operation of the equipment. If this happens, the telephone
company will provide advance notice in order for you to
make the necessary modifications in order to maintain
uninterrupted service.
6. If your modem needs to be returned for repair or
replacement, follow the return policy as indicated on your
warranty card.
7. No repairs may be made by the end use customer.
8. This modem cannot be used on public coin service provided
by the telephone company. Connection to Party Line Service
is subject to state tariffs. (Contact the state public utility
commission, public service commission or corporation
commission for information.)
9. The Telephone Consumer Protection Act of 1991 makes it
unlawful for any person to use a computer or other
electronic device to send any message via a telephone fax
machine unless such message clearly contains in a margin
at the top or bottom of each transmitted page or on the first
page of the transmission, the date and time it is sent and an
identification of the business or other entity, or other
individual sending the message and the telephone number
of the sending machine of such business, or other entity, or
individual.
In order to program this information, follow the steps outlined
in the manual supplied with your fax software.
10. An FCC compliant telephone cord with modular plugs is
provided with this equipment. This equipment is designed to
be connected to the telephone network or premises wiring
using a compatible modular jack which is Part 68 compliant.
Issue 1 November 1994
D
Important Regulatory Information
EMI Warnings
! WARNING:
This equipment has been tested and found to comply with
the limits for a Class B digital device, pursuant to Part 15 of
the FCC rules. These limits are designed to provide
reasonable protection against harmful interference in a
residential installation. This equipment generates, uses, and
can radiate radio frequency energy and, if not installed and
used in accordance with the instruction, may cause harmful
interference to radio or television reception, which can be
determined by turning the equipment off and on. The user is
encouraged to try to correct the interference by one or more
of the following measures:
G
Reorient or relocate the receiving antenna
G
Increase the separation between the equipment and
receiver
G
Connect the equipment into an outlet on a circuit
different from that to which the receiver is connected
G
Consult the dealer or an experienced radio/TV technician
for help
! WARNING:
The authority to operate this equipment is conditioned by the
requirement that no modifications will be made to the
equipment unless the changes or modifications are expressly
approved by AT&T Paradyne.
To Users of Digital Apparatus in Canada:
This digital apparatus does not exceed the Class B limits for
radio noise emissions from digital apparatus set out in the
radio interference regulations of the Canadian Department of
Communications.
Le presént appareil numérique n’émet pas de bruits
radioélectriques dépassant les limites applicables aux
appareils numériques de la Classe B prescrites dans le
règlement sur le brouillage radioélectrique édicté par Le
Ministère des Communications du Canada.
E
Issue 1 November 1994
Important Regulatory Information
Canada
Notice To The Users Of The Canadian
Public Switched Telephone Network
The Canadian Department of Communications label identifies
certified equipment. This certification means that the equipment
meets certain telecommunications network protective,
operational and safety requirements. The Department 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.
Users should ensure for their own protection that the electrical
ground connections of the power utility, telephone line 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 for this equipment is listed on the modem’s
label. 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 devices does not exceed 100.
Issue 1 November 1994
F
Important Regulatory Information
If your equipment is in need of repair, return it to its place of
purchase or arrange to have your equipment repaired by
contacting Inventory Control Office, 100 York Blvd., Suite 200,
Richmond Hill, Ontario L4B1J8, telephone (416) 494-0453.
G
Issue 1 November 1994
Contents
1
Introduction
G Welcome to the World of Portable, High-Speed
Data Communications! . . . . . . . . . . . . . . . . . . .
G KeepInTouch Card Modem Package . . . . . . . . . . . .
Supplied Equipment . . . . . . . . . . . . . . . . . . . . . .
Additional Equipment You Will Need . . . . . . . .
G Where to Find Additional Information . . . . . . . . . . . .
2
1-1
1-2
1-2
1-3
1-3
Installation
G KeepInTouch Card Modem Installation
Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
G Fax Application Software . . . . . . . . . . . . . . . . . . . . . . 2-3
3
Using Your Modem
G
G
G
G
G
G
G
G
What is a Modem? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Operating Modes (Command and Data) . . . . . . . . . 3-2
Using AT Commands . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Making a Call with Your Modem . . . . . . . . . . . . . . . . 3-4
Dial Modifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Examples of Dial Command Strings . . . . . . . . 3-6
Disconnecting a Call . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Manually Answering a Call . . . . . . . . . . . . . . . . . . . . . 3-8
Using the Escape Sequence — Switching Between
Data Mode and Online Command Mode . . . . 3-9
Viewing, Selecting, and Saving Modem Settings . . 3-9
View User Profile Command (&V) . . . . . . . . . . 3-10
Save (Write to Memory) Command (&W) . . . . 3-10
Reload Factory Settings Command (&F) . . . . 3-11
Reload Settings from a User Profile (&Y) . . . . 3-12
Reset Modem and Load User Profile (Z) . . . . 3-12
Issue 1 November 1994
i
Contents
G An Overview of File Transfers and Fax
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
File Transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
Fax Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
4
AT Command Set and S-Registers
G AT Commands and S-Registers . . . . . . . . . . . . . . . . 4-1
A
Troubleshooting
A-1
B
Technical Specifications
B-1
C
Response Codes
C-1
D
Advanced Modem Concepts
G Changing Modem-to-Modem Connection
Data Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1
G Error Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-2
G Data Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3
G Flow Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-3
Modem-to-Computer Flow Control . . . . . . . . . D-4
Computer-to-Computer Flow Control . . . . . . . D-5
Modem-to-Modem Flow Control . . . . . . . . . . . D-6
GL Glossary
GL-1
IN
Index
IN-1
ii
Issue 1 November 1994
Figures
1
Introduction
G 1-1
2
Installation
G 2-1
3
Modem Installation . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Using Your Modem
G 3-1
D
Supplied Equipment . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Dial Data Network . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Advanced Modem Concepts
G D-1 Modem-to-Computer Flow Control . . . . . . . . . . . D-4
G D-2 Various Flow Control Methods . . . . . . . . . . . . . . . D-6
Issue 1 November 1994
iii
Tables
4
AT Command Set and S-Registers
G 4-1
G 4-2
A
Troubleshooting
G
G
G
G
G
B
AT Command Reference . . . . . . . . . . . . . . . . . . . . 4-2
S-Register Reference . . . . . . . . . . . . . . . . . . . . . 4-20
A-1
A-2
A-3
A-4
A-5
Modem Health . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Modem — Computer Connection . . . . . . . . . . . .
Modem — Telephone Line Connection . . . . . . . .
Online Operation . . . . . . . . . . . . . . . . . . . . . . . . . .
Fax Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A-2
A-2
A-3
A-7
A-7
Technical Specifications
G B-1 Technical Specifications . . . . . . . . . . . . . . . . . . . . B-1
C
Response Codes
G C-1 Response Codes Enabled by X and
\V Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2
G C-2 Basic Response Codes (\V0) . . . . . . . . . . . . . . . . C-2
G C-3 Modified Response Codes (\V1) . . . . . . . . . . . . . C-3
G C-4 V.42 Extended Response Codes (\V2) . . . . . . . . C-4
iv
Issue 1 November 1994
Introduction
1
Welcome to the World of
Portable, High-Speed Data
Communications!
Congratulations on your purchase of an AT&T Paradyne
KeepInTouch Card modem. The KeepInTouch Card is a credit
card size modem that combines high-speed V.32bis data
communications with send-and-receive fax capability. The
modem fits into any notebook or laptop personal computer that
has a Personal Computer Memory Card International
Association (PCMCIA) Type II socket, and allows you to keep in
touch with your home or office from anywhere in the United
States and Canada.
The KeepInTouch Card high-speed modem can transmit and
receive information over a standard telephone line at 14,400 bits
per second. It is compatible with a variety of modem standards,
allowing it to communicate with slower modems. To ensure
error-free data transfers, the KeepInTouch Card modem
employs V.42 and MNPr Levels 4–2 error control. To increase
effective data throughput and reduce the duration of calls, the
modem supports both V.42bis and MNP5 data compression
standards to achieve peak transmission rates up to 57,600 bps.
For fax operation, the modem supports the Class 1 fax
standard. The modem also supports the CCITT V.17 fax
protocol which allows fax transfers to occur over standard
telephone lines at 14,400 bps. To take advantage of the
14,400 bps data rate, you must connect to a fax machine or fax
modem that also supports the V.17 protocol.
Issue 1 November 1994
1-1
Introduction
KeepInTouch Card Modem
Package
The following sections describe what equipment is supplied and
what equipment is required to install and operate the modem
(see Figure 1-1).
Supplied Equipment
The following hardware and software is included with the
modem:
G
One KeepInTouch Card modem.
G
One user’s guide.
G
A 2-pin modular telephone cord.
The following items are optional and may not be packaged with
your modem:
G
Diskettes and user’s guides for software which allows
you to send data and fax transmissions.
G
A technical information update sheet (if applicable).
Figure 1-1. Supplied Equipment
1-2
Issue 1 November 1994
Introduction
Additional Equipment You Will Need
The following additional hardware and software is necessary to
install and operate your modem.
G
A notebook or laptop personal computer that supports a
PCMCIA Type II socket.
G
Card and Socket Services that comply with PCMCIA
Release 2.1. These are PCMCIA drivers which should
already be installed on your PC.
G
A communications software application to allow the PC
to control the modem (if not supplied with your modem).
This type of software application will allow you to use
your modem to transfer files to and from your PC,
receive electronic mail (e-mail), dial into bulletin boards,
etc.
G
If fax operations are desired, you will also need fax
application software to control fax operation (if not
supplied with your modem).
G
A telephone outlet (RJ11C in the USA, CA11A in
Canada).
Where to Find Additional
Information
You may have access to a Bulletin Board System (BBS) if there
is a BBS telephone number on your warranty card. Information
on software applications and compatible PC platforms may be
found on the BBS.
A technical support telephone number is provided on your
warranty card.
NOTE:
The first page in this User’s Guide contains space for
recording technical support and BBS telephone numbers.
Issue 1 November 1994
1-3
Installation
2
KeepInTouch Card Modem
Installation Procedures
This section describes how to install your Model 3760-B2
KeepInTouch Card modem. Please take a minute to review
these procedures before installing your modem.
Use Figure 2-1 and the following procedures to install your
modem.
1. Locate an unused PCMCIA socket on your PC. Refer to
your PC’s user’s guide for more information about the
PCMCIA socket.
2. Hold the modem so that the product logo label is facing up,
and the 68-pin connector is facing the PCMCIA socket.
! CAUTION:
Use care when inserting the modem into the socket.
Do not force the modem, as that may damage the pins on
the connector.
Insert the modem into the socket, pushing it all the way in so
that all 68 pins are engaged.
Issue 1 November 1994
2-1
Installation
Figure 2-1. Modem Installation
3. Connection to a Telephone Outlet
Plug the modular cord’s 2-pin connector into the modem’s
2-pin rear edge connector. Since the 2-pin connector is not
keyed, it does not matter which way it is plugged in.
Next, plug the cord’s modular telephone plug into the
telephone jack.
! CAUTION:
If you need to remove the modem from the PCMCIA socket,
be sure to unplug the modular cord’s 2-pin connector from
the modem before removing the modem from the PC. Refer
to your PC’s documentation for instructions on removing the
modem from the socket.
2-2
Issue 1 November 1994
Installation
4. Make sure that your modem is installed and that your
PCMCIA slot is set-up for modem operation before using a
communications or fax application.
5. Your PC must now be set up to recognize the modem. This
task is performed automatically by the PCMCIA card
enablers, also called Card and Socket services, which are
installed on your PC by the manufacturer. Refer to the
documentation provided with your PC for more information
on the Card and Socket Services installed on your PC.
NOTE:
The COM port and IRQ setting for your modem are
determined by the PCMCIA card enablers on your PC.
You will need to know these values when you set up your
communications and fax software applications. Refer to
your PC’s documentation for information on where to find
the COM port and IRQ settings.
Fax Application Software
Some KeepInTouch Card modems ship with software which will
allow you to send and receive facsimiles. Before installing any
fax software, make sure the modem is installed and configured
in your computer. Follow the installation and operation
instructions which are packaged with your fax software. For
COM port and IRQ information, refer to your PC’s
documentation.
Issue 1 November 1994
2-3
3
This chapter highlights some of the basic functions and
commands necessary to operate your modem. Whether you
consider yourself a novice or an experienced user in data
communications, you may want to read through some of the
examples to become familiar with your modem’s operation. For
information on more advanced concepts such as altering data
rates, error correction, data compression, and flow control, see
Appendix D, Advanced Modem Concepts.
What is a Modem?
A modem is simply a device that facilitates the movement of
information back and forth from one computer to another using a
regular telephone line as a transmission path. Picture the
modem as a telephone for computers in that it performs many of
the telephone functions you are familiar with, such as dialing,
answering and disconnecting a call. However, to do this for
computers your modem must go one step further.
A modem translates the way a computer communicates, using
digital signals, into a format acceptable for transmission over a
telephone line, which uses analog signals. Once information is
sent from your modem across the telephone line to another
modem, the analog signal is converted back into a digital signal
so that the receiving computer can use it. This process of
modulating (converting) and demodulating (detecting) a signal
gives us the acronym, modem (see Figure 3-1).
Issue 1 November 1994
3-1
Using Your Modem
Figure 3-1. Dial Data Network
Operating Modes (Command
and Data)
Before a modem goes online (establishes a successful
connection with a remote modem), it is considered to be in
Command mode, an idle state where you can modify its
operating parameters or issue modem commands. (Any
command issued is acknowledged with a response in either
words or digits. These are known as response codes and are
listed in Appendix C.)
Once the modems are online, either by answering or placing a
call, they automatically switch to Data mode. Data mode is a
state where any entries made from the computer are considered
data and are transmitted and received between modems. The
modems remain in Data mode until the connection is broken or
until they are forced into online Command mode using the
escape sequence (+++).
The escape sequence is a series of characters you type in to
switch from Data mode to online Command mode. Use the
escape sequence when you want to enter a command to the
modem while it is in Data mode. The connection between the
modems will not be broken. Think of the escape sequence as a
way to get the modem’s attention when it is sending or receiving
data.
The escape sequence consists of three plus signs (+++). When
you enter the escape sequence, you must precede the +++ by a
small amount of idle time, known as an escape guard time.
3-2
Issue 1 November 1994
Using Your Modem
Another period of idle time must also follow the escape
sequence before you enter any AT commands. This idle time
before and after the escape sequence prevents the escape
sequence characters from being misinterpreted as part of the
data stream being sent between the modems. An example of
how to use the escape sequence is provided on page 3-9.
Using AT Commands
The KeepInTouch Card modem uses AT commands and
S-Registers to control its operation. These commands are
issued to your modem from your computer through your
communications software package.
To use AT commands, the modem must be in either Command
mode or online Command mode. If the modem is in Data mode,
you will need to enter the escape sequence (+++) to switch to
Command mode (see page 3-9) before entering a command.
Please review the following guidelines before using any
AT commands.
G
All commands (except A/ (which is used to repeat the
last command) and +++ (escape sequence)) must begin
with the characters AT and end by pressing the Enter
key.
G
The AT (or at) prefix (which means attention) can be
upper- or lowercase, but the modem will not recognize
mixed case prefixes (At or aT).
G
The data character format (how your data is structured)
for the AT command set must be one of the following. It
can be set using your communications software:
— 8 data bits + no parity + 1 stop bit.
— 7 data bits + parity + 1 stop bit (parity can be
odd, even, mark, or space).
G
S-Registers also require the AT prefix. To change an
S-Register, use the ATSn=x command, where n is the
number of the S-Register and x is the new value to be
stored in that register. S-Registers are described in
Table 4-2. which begins on page 4-20.
Issue 1 November 1994
3-3
Using Your Modem
G
Commands can be entered one at a time or in strings
(several commands at once – for example, ATM1L2).
Strings can have up to 40 characters after the AT prefix.
Spaces, parentheses, and hyphens are not considered
characters.
G
Commands described in this manual which end with the
suffix n have several options associated with them. For
example, in the I command, I0 causes the modem to
report its product code while I1 causes the modem to
report its firmware version number. If no value is entered
for the n variable, the modem assumes a default value
for n. The default value is different for each command.
Refer to Chapter 4, AT Command Set and S-Registers,
for each commands’ default value (where applicable).
G
Valid commands are acknowledged with numeric or word
response codes (unless the response codes have been
disabled using the Q1 command). Appendix C,
Response Codes, lists all the response codes with
numeric and word equivalents.
NOTE:
All commands supported by the your modem are
described in Chapter 4, AT Command Set and
S-Registers.
Making a Call with Your
Modem
The dial command (D) is used to place a call. When the modem
receives this command, it goes off-hook and connects the
modem to the phone line so that a call can be made (similar to
picking up a telephone’s handset), and dials the telephone
number specified in the command string.
Dial command strings contain the dial command (D), dial
modifiers, and the telephone number. A dial modifier tells the
modem to perform additional tasks when dialing a telephone
number.
3-4
Issue 1 November 1994
Using Your Modem
Dial Modifiers
The following can be used as dial modifiers:
T – Touch-tone dialing. Any digit 0—9, * , # , A, B, C, or D can
be dialed as tone.
P – Pulse dialing. Only the digits 0—9 can be dialed in Pulse
Dial mode.
- , ( ), and Space. These characters are ignored by the dial
string and can be included in the dial string to enhance
readability.
, – Pause. Causes the modem to pause before processing the
next character in the dial string. The length of this pause is
determined by the value held in S-Register S8, the Pause Time
configuration option.
W – Wait for dial tone. The modem waits for a specified time
before expecting a second dial tone, then begins processing the
dial string. For example, if you must dial a 9 to reach an outside
telephone line, the W modifier delays the modem from dialing
until it receives a second dial tone for the outside line. The
amount of time the modem waits is determined by the setting of
S-Register S6. Once a dial tone is detected, or if the time period
runs out, the modem will then process the next command in the
dial string. If a busy signal is detected, the modem will respond
with a busy response code and then go into off-line command
mode.
R – Reverse Dial mode. Causes the originating modem to send
out an answer tone once it no longer detects ringback.
(Ringback is the ring you hear at the originating site when
making a call.) The R parameter must be the last character in
the dial string. For correct operation, at least one ringback must
be detected; therefore, the remote modem should be placed
off-hook into originate mode on the second ring or later.
S=n Dial Stored Telephone Number. Causes the modem to
dial the telephone number which was previously stored in
memory by an &Zn command.
@ – Wait for Quiet Answer. The modem will wait for a specified
amount of time (determined by S-Register S7), followed by five
seconds of silence before processing the next dial modifier. If
the silence is not detected, the modem sends a NO ANSWER
result to the computer.
Issue 1 November 1994
3-5
Using Your Modem
! – Hook flash. This causes the modem to go on-hook for a
0.75 seconds.
; – Return to Command mode. Modem returns to Command
mode after dialing a number without disconnecting the call. This
allows AT command strings that exceed the 40-character limit to
be linked together and is useful when using a calling card
number or an international telephone number.
Examples of Dial Command Strings
Local Call using Tone Dialing
In this example, D is the dial command, T is the Tone dialing
modifier, and 555-1234 is the telephone number.
TYPE:
ATDT 5551234
PRESS: Enter
Calling through a Private Branch
Exchange (PBX)
In this example, Tone dialing is selected, a 9 is dialed to pass
through the PBX (to get an “outside” line), the modem will wait
for a dial tone (due to the W modifier) and then dial the
telephone number 555-1234.
TYPE:
ATDT9W555-1234
PRESS: Enter
Dialing a Stored Telephone Number
This example shows how to dial a number which has been
stored in the memory of the modem. You can use the &Z
command to store up to four different telephone numbers in
memory. In this case, the modem will dial the number stored in
memory location 2. For more information on &Z, see page 4-17.
TYPE:
ATDS=2
PRESS: Enter
3-6
Issue 1 November 1994
Using Your Modem
Calling long distance
This is another example of using Tone dialing, this time to place
a long distance call. The spaces, parentheses, and dashes are
used to make the number easier to read, but are ignored by the
modem.
TYPE:
ATDT 1 (813) 555-1234
PRESS: Enter
If you would like to know more about the function of the dial
command, refer to the following commands in Chapter 4:
P (Pulse), T (Tone), &Z (Store Telephone Numbers), S6 (Blind
Dial Pause Time), S7 (No Answer Time-out), and S8 (Pause
Time Dial Modifier).
Disconnecting a Call
Two ways you can disconnect a call are the H command and
DTR disconnect.
To disconnect using the H command, enter online Command
mode and issue an ATH command to make your modem hang
up, or go on-hook.
TYPE:
+++
To exit Data mode and enter online Command
mode. (The +++ is an escape sequence,
described on page 3-2.)
TYPE:
ATH
To issue the command to hang up.
PRESS: Enter
The modem disconnects.
A third, and more subtle approach to hanging up a call, is to
make sure that the &D command is set to &D2 (the factory
default setting which is standard for EIA RS-232 operation). This
will allow your communications software to drop the DTR signal
to the modem and force the modem to disconnect the call. This
method is often used by communications software.
Also note that your modem will automatically disconnect when
the remote modem hangs up.
Issue 1 November 1994
3-7
Using Your Modem
If you would like to know more about disconnecting a call, refer
to the following commands in Chapter 4: +++ (escape
sequence), O (Return to Online Data Mode), X (Response
Codes, Dial Tone Detect, Busy Tone Detect), Y (Long Space
Disconnect), &D (DTR Control), \N (Set Operating Mode),
\T (Set Inactivity Timer), S7 (No Answer Time-out), and
S10 (No Carrier Disconnect).
Manually Answering a Call
The best way to answer a call is to set the Auto-Answer Ring
Number register (S0) to 1 or more rings. To enable this feature,
set the value of S0 to 1 or more rings. If S0 = 0 (which is the
default setting from the factory), you can use the ATA command
to manually answer incoming calls.
To use the A command to manually answer a call:
TYPE:
ATA (after the modem rings)
PRESS: Enter
NOTE:
DTR must be present (activated by the communications
software) for the modem to answer the call.
3-8
Issue 1 November 1994
Using Your Modem
Using the Escape Sequence —
Switching Between Data Mode
and Online Command Mode
To enter online Command mode while in Data mode, enter the
following sequence. For more information on Command and
Data modes, see page 3-2.
TYPE:
+++
The modem enters online Command mode and
responds with an OK.
NOTE:
The value of the escape sequence character (+++) and
the idle time required before and after an escape
sequence are determined by the S2 and S12 registers. If
you want to change these values, refer to the descriptions
of these S-Registers in Chapter 4.
To return to Data mode from online Command mode, use the
O command. Enter the following command:
TYPE:
ATO
PRESS: Enter
Viewing, Selecting, and Saving
Modem Settings
Modem settings determine how the modem functions. These
settings are known as configuration options and are stored in
two permanent memory areas, User Profile 0 and
User Profile 1.
When the modem is initially turned on, the contents of one of the
two memory areas are retrieved into a volatile work area of
memory known as the Active User Profile. (The &Y command
determines which of the two user profiles will be retrieved.) If
you should make changes to the modem’s configuration and
then turn the modem off without saving those changes, they are
lost forever.
Issue 1 November 1994
3-9
Using Your Modem
On the other hand, User Profile 0 and User Profile 1 are
nonvolatile memory areas that can permanently store
configuration options to the modem’s Electrically Erasable
Programmable Read Only Memory (EEPROM) chip. If your
modem requires a particular configuration to work with an
application, then those settings can be created and saved to one
of the two nonvolatile memory areas.
If you would like to know more about viewing, saving, and
reloading user profiles, refer to the following commands in
Chapter 4: &V (View Active and Stored User Profiles),
&W (Write Changes to Memory ), &F (Load Factory Defaults),
and Z (Reset and Load Stored Profile).
View User Profile Command (&V)
The &V command displays a summary of the modem’s Active
User Profile, as well either User Profile 0 or User Profile 1.
To use the &V command:
TYPE:
AT&Vn
where n is
0 to view the Active User Profile and
User Profile 0.
1 to view the Active User Profile and
User Profile 1.
PRESS: Enter
Save (Write to Memory) Command
(&W)
Anytime a change is made to a configuration option, it can be
saved to either the User Profile 0 or User Profile 1 memory area
using the &W command. (Remember that Active is a temporary
work area your modem operates out of. A loss of power or a
reset discards any changes made in the Active area.)
3-10
Issue 1 November 1994
Using Your Modem
To use the &W command:
TYPE:
AT&Wn
where n is 0 for User Profile 0 and 1 for User
Profile 1.
PRESS: Enter
The changes are saved and the modem responds
with an OK.
Reload Factory Settings Command (&F)
The modem ships from the factory ready to operate with your
computer and transfer data over a normal telephone line. If you
have changed several configuration options that no longer apply
to what you want to do, you can reload the original factory
template with the &F command.
To use the &F command:
TYPE:
AT&F
PRESS: Enter
The factory configuration is loaded into the Active User Profile
and the modem is set up for Data Mode.
These are some of the features and functions available to you
when the factory configuration is loaded:
G
V.32bis operation with a dial line data rate of 14,400 bps.
G
V.42 and V.42bis error control and data compression.
G
MNP 5 data compression.
G
RTS/CTS flow control.
G
CD and DTR set for standard RS232 operation.
G
DSR forced on.
G
“Word” response codes, response codes enabled.
G
V.32bis Automoding which allows the modem to connect
with non-V.32bis modems.
G
Busy and Dial tone detection enabled.
If you want to save this to a storage area, you can add the &W
command after the &F command listed above.
Issue 1 November 1994
3-11
Using Your Modem
Reload Settings from a User Profile (&Y)
Use the &Y command to select whether the contents of either
User Profile 0 or User Profile 1 are loaded into Active memory
each time the modem turns on or when a reset command (Z) is
issued.
To use the &Y command:
TYPE:
AT&Yn
where n is 0 for User Profile 0 and 1 for User
Profile 1.
PRESS: Enter
Reset Modem and Load User Profile (Z)
Use the Z command to reset the modem and load the contents
of User Profile 0 or User Profile 1 into the the modem’s Active
memory area.
To use the Z command:
TYPE:
ATZn
where n is
0 to reset the modem and load the User Profile 0
settings into Active memory.
1 to reset the modem and load the User Profile 1
settings into Active memory.
PRESS: Enter
The Z command must be the last command in the command
string, because any commands after it will be ignored.
An Overview of File Transfers
and Fax Operation
The purpose of this section is to make you aware of the basic
concepts involved when using your modem to transfer and
receive files and fax messages. For information on how to use
your communication or fax software, you will need to refer to the
documentation provided with your software package.
3-12
Issue 1 November 1994
Using Your Modem
File Transfers
Two terms essential to file transfers are download and upload.
A download occurs when you want to receive a file from a host
site (such as a BBS or another computer). An upload occurs
when you want to send a file to a host site. However, before you
can do this, the following must occur:
G
Your modem and PC must be configured for modem
operation before executing your communications
software.
G
You must have communications software that is
operating and in terminal mode.
G
Your modem must be online with another modem.
G
Determine whether you want to upload or download files.
G
Verify that the character format (7 data bits, odd parity,
1 stop bit; 8 data bits, no parity, 1 stop bit; and so on) is
the same for both the local and remote modems.
G
Select a file transfer protocol (ZMODEM, YMODEM,
XMODEM, Kermit, and so on) that is compatible with
your communications software and remote system.
Some protocols require simultaneous actions at both
ends of the link to start a transfer, while others permit
initiation of the transfer from one side only.
NOTE:
ZMODEM protocol is recommended for its speed and
reliability, if your data communications software supports
this protocol.
A file transfer protocol sets up the ground rules that your modem
and the remote system will use to move files back and forth.
Your communications software manual will describe the various
protocols it supports, and the software program will usually walk
you through the download/upload process.
Issue 1 November 1994
3-13
Using Your Modem
Fax Operation
Fax software essentially turns your computer and modem into a
fax machine and allows you to send a file to or receive a file
from another fax modem or fax machine.
Similar to your communications software, your fax software uses
basic AT commands for functions such as dialing and answering
calls and for speaker control and adjustments. Refer to your
communication software’s user’s guide for more information on
AT command support.
Before sending or receiving a fax, verify the following:
G
Your modem and PC must be configured for modem
operation before executing your fax software.
G
You must have fax software installed on your PC. (For
the KeepInTouch Card modem, if sending or receiving a
fax, the software must be operating.)
G
Some fax software packages require the modem to have
Auto-Answer disabled (S0 = 0) to receive a fax.
G
Some fax software packages require that the modem use
software flow control (\Q1) to send and receive a fax.
Refer to your fax software documentation for more on fax
operation.
3-14
Issue 1 November 1994
4
AT Commands and S-Registers
This chapter provides a list of all AT commands and S-Registers
supported by the KeepInTouch Card modem. This chapter first
lists AT commands in alphabetical order followed by S-Registers
listed in numerical order. Factory settings are listed in bold.
In general, AT commands are responsible for instructing the
modem to do a task, such as dialing, hanging-up, loading factory
default settings, etc. However, some AT commands, and most
S-Registers, are responsible for setting configuration options
which determine how the modem operates. You issue these
commands to your modem via your communications software.
When a modem receives a command, it responds with a
message, known as a response code, that displays on your
monitor. Response codes are described in Appendix C.
For a brief overview of command guidelines, refer to the Using
AT Commands section in Chapter 3, Using Your Modem.
The AT commands supported by the modem are described in
Table 4-1. S-Registers are described in Table 4-2.
Issue 1 November 1994
4-1
AT Command Set and S-Registers
Table 4-1. AT Command Reference (1 of 18)
AT
Command Description
+++
Escape sequence
The escape sequence allows the modem to exit Data mode
and enter online Command mode. For more information on this
command, see Chapter 3.
A/
Repeat Last Command
This command re-executes the last ‘AT’ command string
stored in the command buffer. The A/ command is the only
command not preceded by ‘AT’ and ended by a carriage
return.
A
Answer Command
Allows the modem to go off-hook and attempt to answer an
incoming call.
Bn
CCITT/Bell Mode
This command selects whether the modem is configured as a
CCITT or BELL modem.
Cn
B0
Selects CCITT V.22 when the modem is at 1200 bps.
B1
Selects Bell 212A when the modem is at 1200 bps,
and Bell 103J when the modem is at 300 bps.
Carrier Control Option
This command is reserved for selecting between controlled
carrier or constant carrier modes. This modem supports only
constant carrier mode.
4-2
C0
Transmit carrier always off (returns an ERROR
message).
C1
Normal Transmit carrier.
Issue 1 November 1994
AT Command Set and S-Registers
Table 4-1. AT Command Reference (2 of 18)
AT
Command Description
D
Dial
This command causes the modem to immediately go off-hook
and dial a telephone number with corresponding dial modifiers.
Dial modifiers are parameters that define how the modem
should dial the telephone number.
0–9
Dialing digits
A,B,C,D, *, # Tone Dial Characters
P
Pulse Dial — Configures the modem to use pulse
dialing to dial a telephone number.
R
Reverse Originate Mode — Places the modem in
answer mode. This modifier should be the last
character in the dialing string (e.g. ATDT 123-4567R)
S=n
Dial Stored Telephone Number — Causes the modem
to dial a telephone number that has been previously
stored in the modem’s memory with the AT&Zn=x
command.
T
Tone Dial — Configures the mode to use DTMF tones
to dial a telephone number.
W
Wait for Dial Tone — Causes the modem to look for
dial tone for a specified amount of time. If dial tone or
the amount of time specified by the S-Register S6
times-out, the modem will then process the next
command in the dial string. If a busy signal is detected,
the modem will respond back to the computer with a
busy response code, and then go into off-line
command mode.
,
Pause — Causes the modem to pause or delay
implementing the next parameter in the dial string by
the time specified in S-Register S8.
!
Flash Hook — Causes the modem to go on-hook for
0.75 seconds.
@
Wait for Quiet Answer — Causes the modem to wait for
specified amount of time (S-Register S7) followed by
5 seconds of silence before processing the next dial
modifier.
;
Return to Idle State — Causes the modem to enter
on-line command mode without initiating a data modem
handshake (used for phone directory auto-dialers).
–()
Ignored by Modem — These four characters are
ignored by the modem, but space may be included in
the dial string for separating area codes and numbers.
Issue 1 November 1994
4-3
AT Command Set and S-Registers
Table 4-1. AT Command Reference (3 of 18)
AT
Command Description
En
Command Character Echo
This command controls whether or not the characters you
enter from your computer’s keyboard are echoed back to your
monitor when the modem is in Command mode.
Fn
E0
Disables echo.
E1
Enables echo.
On-line Echo
This command is normally used to select whether the modem
echoes data back to the host during online data mode. This
device set does not support online data mode echo.
Hn
F0
Echo enabled (returns an error message).
F1
Echo disabled.
Hook
This command lets the modem go on-hook to disconnect a call
or off-hook to make the telephone line busy.
In
H0
The modem goes on-hook (disconnects a call).
H1
The modem goes off-hook.
Identification/Checksum Option
This command displays specific information about your
modem and allows you to verify the ROM checksum.
I0
Displays product code .
I1
Displays firmware revision number.
I2
Verifies ROM Checksum.
I3
Displays device set name.
K
Reserved. (Should always be set to K1.)
L
Reserved.
Mn
Speaker On/Off Control
4-4
M0
Speaker always off.
M1
Speaker on until carrier signal becomes active.
M2
Speaker always on.
M3
Speaker off during dialing and on until carrier signal
becomes active.
Issue 1 November 1994
AT Command Set and S-Registers
Table 4-1. AT Command Reference (4 of 18)
AT
Command Description
Nn
Select Data Rate Handshake
This command allows you to select whether or not the
modem-to-modem data rate can be different than the local
computer-to-modem data rate. For more information on this
command, refer to Appendix D, Advanced Modem Concepts.
On
N0
Only communicate at the local computer-to-modem
data rate. This option is only needed for specialized
applications and is not recommended for most users.
N1
Attempt to use the local computer-to-modem data
rate, but if the remote modem does not support
that rate, fall down to the highest compatible data
rate.
Return to Online Data Mode
This command allows you to exit Online Command mode and
return to Data mode.
P
O0
Returns the modem to Data mode.
O1
Begins an equalizer retrain sequence, then returns to
Data Mode. This command is only valid for 2400 bps
connections.
Pulse Dial (Used with rotary telephone lines)
This command configures the modem for Pulse dialing. To
disable Pulse dialing issue the T (tone dial) command.
Qn
Response Codes
This command determines whether or not the modem will send
response codes to the computer.
Sn=x
Q0
Enables response codes.
Q1
Disables response codes.
Change S-Register
This command is used to change the value of an S-Register.
S-Registers are described in Table 4-2, which begins on
page 4-20.
n = the number of the S-Register you want to change.
x = the new value for S-Register n, in decimal format.
For example, ATS18=20 will load the value 20 into
S-Register 18.
Issue 1 November 1994
4-5
AT Command Set and S-Registers
Table 4-1. AT Command Reference (5 of 18)
AT
Command Description
Sn?
View S-Register
This command is display the contents of an current S-Register
(in decimal format).
n = S-Register.
T
Tone Dial (Touch-tone dialing method)
This command configures the modem for touch-tone dialing.
This is the default dialing method.
Vn
Response Codes Format
This command controls whether response codes appear as
words or as numbers.
4-6
V0
Displays as numbers.
V1
Displays as text.
Issue 1 November 1994
AT Command Set and S-Registers
Table 4-1. AT Command Reference (6 of 18)
AT
Command Description
Xn
Response Codes, Dial Tone Detect, Busy Tone Detect
This command controls three different configuration options.
Response Codes are the messages from the modem,
displayed as either words or numbers. This command controls
which response codes are reported from the modem.
Refer to Appendix C for more information on response codes.
Dial Tone Detect, if enabled, causes the modem to wait (up to
10 seconds) for a dial tone before dialing. If disabled, the
modem dials the call regardless of dial tone detection (also
known as blind dialing).
Busy Tone Detect, if enabled, sets the modem to monitor for a
busy tone. If disabled, the modem ignores busy tones.
X0
Enables response codes 0–4.
Disables busy and dial tone detect.
X1
Enables response codes 0–5 and 10–17.
Disables busy and dial tone detect.
X2
Enables response codes 0–6 and 10–17.
Disables busy detect.
Enables dial tone detect.
X3
Enables response codes 0–5, 7, and 10–17.
Enables busy detect.
Disables dial tone detect.
X4
Enables response codes 0–7 and 10–17.
Enables busy and dial tone detect .
For all settings except X0, additional response codes may also
be enabled by changing the setting of the \V command.
Response codes are listed in Appendix C.
\V0 enables response codes 10–17.
\V1 enables response codes 10–17 and 22–30.
\V2 enables response codes 10–17 and 32–70.
Issue 1 November 1994
4-7
AT Command Set and S-Registers
Table 4-1. AT Command Reference (7 of 18)
AT
Command Description
Yn
Reserved.
Zn
Reset and Load Stored Profile
This command causes the modem to go on-hook (hang-up),
performs a warm reset, and then load a User Profile (which
has been previously stored in the modem’s memory) into the
Active Profile. This command should be the last command in a
command string, because all subsequent commands are
ignored.
\An
Z0
Resets the modem and loads User Profile 0
options into the Active profile.
Z1
Resets the modem and loads User Profile 1 options
into the Active profile.
Maximum Frame Size
This command determines the maximum frame (or block) size
used for MNP 4–2 error control operation. If the telephone
connection is poor, a smaller frame size may improve the
modem’s performance.
\Bn
\A0
64 characters per frame.
\A1
128 characters per frame.
\A2
192 characters per frame.
\A3
256 characters per frame.
Transmit Break
This command causes the modem to send a break (Attention
signal), for a duration specified by n, to the remote modem.
When n = 0, the default break length is used.
n = 0–9 (break length in 100 msec intervals).
4-8
Issue 1 November 1994
AT Command Set and S-Registers
Table 4-1. AT Command Reference (8 of 18)
AT
Command Description
\Cn
Set Auto-reliable Buffer
In V.42 auto-reliable mode (set by the \N3 command), this
command is used to determine the fallback method and may
enable data buffering. The settings for this command are used
by the modem during the V.42 detection phase.
Online changes to this option do not take effect until a
disconnect occurs.
\Gn
\C0
No data buffering is performed.
\C1
Data is buffered for four seconds or until 200
characters have been received, then switches to
Reliable mode. If the buffer fills up, data passes to the
serial port.
\C2
No data buffering is performed. The modem switches
to normal mode upon receipt of the auto-reliable
fallback character (set by the %A command) and
passes it to the serial port. This feature is used to allow
non-V.42 modems to connect immediately to a V.42
modem without data loss.
Set Modem Port Flow Control
In normal mode (set by the \N0 command or after fallback),
this command enables modem-to-modem flow control using
XOFF (13 hex) and XON (11 hex) characters to stop and start
transmission between modems, respectively.
For more information on flow control, also refer to the \Q and
\X commands.
\G0
Disables modem-to-modem flow control.
\G1
Sets flow control to XON/XOFF.
Issue 1 November 1994
4-9
AT Command Set and S-Registers
Table 4-1. AT Command Reference (9 of 18)
AT
Command Description
\Jn
BPS Rate Adjustment
If enabled, the serial-port speed will automatically be changed
to the modem-connection speed, forcing the user to change
the bps rate of the DTE-to-modem, if needed. If disabled, the
serial-port speed is independent of the connection speed,
which allows much greater throughput when using error
correction and data compression.
For example, if the initial DTE rate is 38,400 bps and the
modem connects to the remote modem at 9600 bps, the
modem automatically lowers its DTE rate and expects to
receive characters from the DTE at 9600 bps. For data transfer
to occur, the DTE rate must then be lowered from 38,400 bps
to 9600 bps.
\Kn
\J0
Disables BPS rate adjustment.
\J1
Enables BPS rate adjustment.
Set Break Control
This command defines what action the modem takes when a
break (Attention signal) is sent or received, as described
below.
NOTE: Using this command is not recommended unless your
communications software supports the Break character and
your application requires you to send or receive break signals.
The break signal is a special character, much like any other
byte of data received by the modem. If expedited breaks are
enabled, the modem acts on the break as soon as it is
received. Non-expedited means that the modem acts on the
break only after clearing any buffered data.
If destructive breaks are enabled, the modem discards the
buffered data.
The serial port is the connection between the PC and its
attached modem. The modem port is the connection between
the modem and the telephone line.
4-10
Issue 1 November 1994
AT Command Set and S-Registers
Table 4-1. AT Command Reference (10 of 18)
AT
Command Description
\Kn
(cont’d)
If Connected and using a Reliable Mode (\N2, \N3, or \N4),
then transmit break to remote modem:
\K0, \K2, \K4
Enter command state but do not
send a break.
\K1
Destructive/expedited.
\K3
Non-destructive/expedited.
\K5
Non-destructive/non-expedited.
If in Command mode and using a Reliable Mode (\N2, \N3, or
\N4), then transmit break to remote modem:
\K0, \K1
Destructive/expedited.
\K2, \K3
Non-destructive/expedited.
\K4, \K5
Non-destructive/non-expedited.
If connected and using Direct Mode (\N1), then transmit break
to remote modem:
\K0, \K2, \K4
Expedited and enter Command
mode.
\K1, \K3, \K5
Expedited.
If connected, receive break from modem port, send break to
serial port:
\K0, \K1
Destructive/expedited.
\K2, \K3
Non-destructive/expedited.
\K4, \K5
Non-destructive/non-expedited.
Issue 1 November 1994
4-11
AT Command Set and S-Registers
Table 4-1. AT Command Reference (11 of 18)
AT
Command Description
\Nn
Set Operating Mode
This command determines the type of connection attempted
by the modem. For more information on this command, refer to
Appendix D, Advanced Modem Concepts.
\N0
Normal Mode — No data compression or error
correction, but uses speed buffering.
\N1
Direct Mode — No data compression, error correction,
or speed buffering.
\N 2
MNP Reliable Mode — The modem attempts to
negotiate an MNP error-correction ‘reliable’ link,
hanging up if it fails.
\N 3
V.42 Auto-reliable Mode — If V.42 detection is
enabled (by using the – J1) command, a LAPM or
MNP link can be detected and negotiated,
otherwise only LAPM will be attempted.
\N4
V.42 Reliable — The modem attempts to negotiate
LAPM error correction, hanging up if it fails.
NOTE: 300 bps does not support synchronous operation. The
mode will automatically fall back to MNP asynchronous
operation.
\O
Reserved.
\Qn
Set Serial Port Flow Control
This command specifies the DTE-to-modem flow control.
Software flow control uses the XOFF (13 hex) and
XON (11 hex) characters to stop and start data transmission,
respectively, both to and from the DTE.
Unidirectional hardware flow control uses the CTS control line
to stop/start data from the DTE only, while bidirectional
hardware flow control also uses the RTS control to stop/start
data from the modem.
For more information on flow control, also refer to the \G and
\X commands.
4-12
\Q0
Disables flow control.
\Q1
Enables XON/XOFF flow control.
\Q2
Enables unidirectional hardware flow control.
\Q3
Enables bidirectional hardware flow control.
Issue 1 November 1994
AT Command Set and S-Registers
Table 4-1. AT Command Reference (12 of 18)
AT
Command Description
\Tn
Set Inactivity Timer
During a normal or reliable connection, this command forces
the modem to disconnect if no data is transmitted or received
within a specified time period.
\Vn
\T0
Disable inactivity timer.
\T1 – 90
Length in minutes.
Change Response Code Set
This command is used to select which modem response codes
are supported. Refer to Appendix C for more information.
\Xn
\V0
Enables Basic response codes (see Table C-2).
\V1
Enables Modified MNP response codes (see
Table C-3).
\V2
Enables Extended V.42 response codes
(see Table C-4).
XON/XOFF Passthrough Flow Control
If software flow control is enabled (\Q1), this command
determines whether XON and XOFF characters received from
the DTE are sent to the remote modem. In addition, if flow
control is enabled (\G1) in normal mode, the command
determines whether the XON and XOFF characters received
from the remote modem are sent to the DTE. In both cases,
flow control operation is not affected.
\X0
Processes flow control characters and removes
them from the data stream.
\X1
Processes flow control characters and passes them
through to the local or remote modem to be processed
as characters.
\Y
Reserved.
\Z
Reserved.
&Cn
Data Carrier Detect (DCD) Control
This command controls the Data Carrier Detect signal.
&C0
State of carrier from the remote modem is ignored.
DCD is always on.
&C1
State of carrier from the remote modem is
tracked. DCD reflects the state of the received
carrier.
Issue 1 November 1994
4-13
AT Command Set and S-Registers
Table 4-1. AT Command Reference (13 of 18)
AT
Command Description
&Dn
Data Terminal Ready (DTR) Control
This command controls what actions are taken by the modem
based upon the Data Terminal Ready (DTR) signal.
&D0
The modem ignores DTR and assumes it is always
active.
&D1
The modem switches from data mode to command
mode when an on-to-off transition of DTR is detected.
(An ATO will return the modem to data mode.)
&D2
An off-to-on transition of DTR causes the modem
to go on-hook (hang-up) and disable auto-answer
mode. Auto-answer mode is enabled again when
DTR is turned back on.
&D3
An on-to-off transition of DTR re-initializes the modem
but does not perform a complete power reset.
NOTE: DTR has to remain off for a minimum amount of time
before the modem will perform any of the actions for this
command. This minimum time period is determined by the
setting of S-Register S25. If DTR is off for less than that time
period, no action is taken. See S25 for more information.
&F
Load Factory Defaults
This command loads the factory configuration options into the
Active Profile area and puts the modem in data mode.
&Gn
Guard Tone
This command determines whether guard tones are sent out
while the modem is connected to a remote modem.
Guard tones are not used in North America but are mandatory
in some countries outside of North America.
&J
4-14
&G0
Disables guard tone.
&G1
550 Hz guard tone enabled.
&G2
1800 Hz guard tone enabled.
Reserved. Should always be set to &J0.
Issue 1 November 1994
AT Command Set and S-Registers
Table 4-1. AT Command Reference (14 of 18)
AT
Command Description
&Pn
Dial Pulse Ratio
This command determines the make/break (off-hook/on-hook)
ratio during pulse dialing.
&P0
Make = 39%, Break = 61% (for use in the United
States).
&P1
Make = 33%, Break = 67% .
(not recommended for use in the United States)
&Q
Reserved. Should always be set to &Q0.
&Sn
Data Set Ready (DSR) Control
This command controls the Data Set Ready (DSR) signal
output from the modem.
&Tn
&S0
DSR circuit is always on.
&S1
DSR circuit is on during handshaking, off in test or idle
modes. DSR remains on until the call is disconnected.
Tests
The &T command allows you to perform diagnostic tests on
your modem.
A test started by commands &T1–&T8 will run until the &T0
command is entered.
&T0
Stops any test in progress and displays results.
&T1
Local Analog Loopback test. This test can only be
performed when the modem is idle (in Command
mode).
&T3
Local Digital Loopback test.*
&T4
Accepts Remote Digital Loopback (RDL) test request
from remote modem.
&T5
Denies Remote Digital Loopback (RDL) test request
from remote modem.
&T6
Remote Digital Loopback test.*
&T7
Remote Digital Loop back test with self-test.*
&T8
Local Analog Loopback test with self-test.
* Test can only be performed when the modem is connected in
a non-error control mode (\N0 or \N1) and the remote
modem is set to allow a remote digital loopback (RDL) test
(&T4).
Issue 1 November 1994
4-15
AT Command Set and S-Registers
Table 4-1. AT Command Reference (15 of 18)
AT
Command Description
&U
Disable Trellis Coding
This command selects whether the modem will transmit and
receive modulated 9600 bps carrier with QAM or Trellis
encoding for V.32.
Trellis coding (forward error correction) is recommended for all
users. When Trellis coding is not used (disabled), the modem
is able to connect on noisier lines at 9600 bps, however, error
rates will increase without the Trellis coding enabled.
&Vn
&U0
Enabled (Trellis modulation with QAM modulation
as a fallback). This is the recommended setting.
&U1
Disabled (QAM modulation only)
View Active and Stored User Profiles
This command displays a summary of the command and
S-Register information in the Active Profile (currently being
used) and in one of the two stored User Profiles. The
telephone numbers which you saved to memory with the
&Z command are also displayed. The User Profile must have
been already saved to memory using the &W command. See
&W for a list of the command settings which are saved.
4-16
&V0
Displays summary of Active Profile, User Profile 0,
and Telephone Directory.
&V1
Displays summary of Active Profile, User Profile 1, and
Telephone Directory.
Issue 1 November 1994
AT Command Set and S-Registers
Table 4-1. AT Command Reference (16 of 18)
AT
Command Description
&Wn
Write (Save) Changes to Memory
This command allows you to save a subset of the Active
Profile configuration options (command and S-Register
settings) in a User Profile. This command stores the
information in the nonvolatile RAM of the modem.
The following command settings are saved:
B
E
L
M
N
P
Q
V
X
Y
&C
&D
&G
&J
&P
&Q
&U
&S
&Y
–C
–J
”H
”O
All S-Register settings are saved.
&Yn
&W0
Saves Active Profile configuration options in User
Profile 0.
&W1
Saves Active Profile configuration options to User
Profile 1.
Load User Profile on Power-up
This command allows you to select one of the two User
Profiles to be loaded into the Active Profile when the modem is
powered up. You must have saved a User Profile with the &W
command prior to using this command.
&Zn=x
&Y0
Selects User Profile 0 to be loaded on power up.
&Y1
Selects User Profile 1 to be loaded on power up.
Store Telephone Numbers
Stores telephone number x into directory n.
n = 0–3 (the directory location in which to store the number).
x = A telephone number and dial modifiers.
Up to 36 characters from the following set:
0–9, A, B, C, D, #, *, T, P, R, W, @, ,,!,;
Issue 1 November 1994
4-17
AT Command Set and S-Registers
Table 4-1. AT Command Reference (17 of 18)
AT
Command Description
%An
Set Auto-reliable Fallback character
In auto-reliable mode (\N3), with auto-reliable fallback
character enabled (\C2), receipt of the fallback character from
the line during the V.42 detection phase will cause the modem
to switch to normal mode. This allows a remote user with a
non-V.42 modem to connect immediately with a V.42 modem.
A space or carriage return (13) is usually chosen for the
fallback character.
n = 0 –127 (ASCII character code). The default is 13.
%Cn
MNP 5 Data Compression
This command enables or disables the use of MNP Level 5
data compression. MNP 5 data compression can improve
throughput by as much as 150%.
%En
%C0
Disables MNP5 data compression.
%C1
Enables MNP5 data compression.
Auto-retrain Control (V.22bis and V.32bis only)
This command controls whether the modem will automatically
initiate a modem retrain whenever the Received Data signal
quality falls below a threshold that may affect data reliability.
%Gn
%E0
Disables auto-retrain.
%E1
Enables auto-retrain.
Auto Fall Forward/Fall Back Control (V.32bis only)
This command selects whether the modem will automatically
initiate a change to a higher or lower speed depending on
received signal quality (i.e., Rate Negotiation). The modem
always responds to any rate change initiated by the remote
modem.
%Q
%G0
Disables rate negotiation.
%G1
Enables rate negotiation.
Line Signal Quality
This information indicates the quality of the telephone line
signal.
0 = Good signal quality
1 = Fair signal quality
2 = Poor signal quality
3 = Equalization loss
4-18
Issue 1 November 1994
AT Command Set and S-Registers
Table 4-1. AT Command Reference (18 of 18)
AT
Command Description
–Cn
Generate Data Modem Calling Tone
This command is used to select whether or not the modem will
send 1300 Hz calling tone when originating a Data Modem
connection.
–Jn
–C0
Disables calling tone.
–C1
Enables calling tone.
Set V.42 Detect Phase
In V.42 modes (\N3, \N4), if this option is enabled, the modem
detects V.42, MNP, or no error-correcting protocols from the
remote modem and changes to the appropriate mode. If this
option is disabled, the modem will detect only the V.42
error-correction protocol from the remote modem.
“Hn
–J0
Disables the V.42 detect phase.
–J1
Enables the V.42 detect phase.
V.42bis Compression Control
This command specifies whether the data in the LAPM frames
are compressed using the V.42bis data compression, which
can improve throughput by as much as 400%. Compression
can be negotiated to operate in only one direction, or in both
directions.
“On
“H0
Disables V.42bis.
“H1
Enables V.42bis only when transmitting data.
“H2
Enables V.42bis only when receiving data.
“H3
Enables V.42bis for both transmitting and receiving
data.
V.42bis String Length
This command specifies the maximum number of characters
that can be compressed into one V.42bis code word. The
default value of 32 optimizes throughput for most file types.
n = 6–250 (number of characters).
Issue 1 November 1994
4-19
AT Command Set and S-Registers
Table 4-2. S-Register Reference (1 of 6)
S-Register Description
S0=n
Auto-Answer Ring Number
This S-Register determines the number of rings the modem
will count before automatically answering a call. A ring count
of 0 will disable the auto answer feature.
n = 0–255. Factory setting is 0 (disables auto-answer).
S1
Ring Count
This S-Register reports the number of rings detected by the
modem. This register is cleared to zero if no rings are
detected within 8 seconds. Valid ring counts reported range
from 0 to 255.
S2=n
AT Escape Character
This S-Register determines the ASCII value used for an
escape sequence (+++).
Accepts an ASCII value from 0 to 127. Any value greater
than 127 will disable the escape sequence.
Factory setting is 43, an ASCII + character.
S3=n
Carriage Return Character
This S-Register determines the ASCII value used as the
carriage return (Enter key).
Accepts an ASCII value from 0 to127.
Factory setting is 13, an ASCII carriage return.
S4=n
Line Feed Character
This S-Register determines the ASCII value used as the line
feed character.
Accepts an ASCII value from 0 to 127.
Factory setting is 10, an ASCII line feed character.
S5=n
Backspace Character
This S-Register determines the ASCII value used as the
backspace (Backspace key).
Accepts an ASCII value from 0 to 32, and 127.
Factory setting is 08, an ASCII backspace character.
4-20
Issue 1 November 1994
AT Command Set and S-Registers
Table 4-2. S-Register Reference (2 of 6)
S-Register Description
S6=n
Blind Dial Pause Time
This S-Register determines how long (in seconds) the
modem waits, after going off-hook, before dialing a
telephone number when Dial Tone Detect has been disabled
(X0, X1, or X3). The dial modifier W causes the modem to
ignore the contents of this register. Result code types X2 and
X4 enable dial-tone detection, but do not use this register.
n = 2–255 (seconds). Factory setting is 2 seconds.
If a value less than 2 is entered, the default value (2) will be
used.
S7=n
No Answer Time-out
This S-Register determines how long (in seconds) an
originating modem waits before abandoning a call when no
answer tone is received. This register also determines the
time duration for the W dial modifier.
n = 1–255 (seconds). Factory setting is 60 seconds.
S8=n
“,” Pause Time for the Dial Modifier
This S-Register determines how long (in seconds) the
modem pauses when it encounters a comma (,) in the Dial
command string.
Accepts a value from 0 to 255 seconds.
Factory setting is 2 seconds.
S9=n
Carrier Detect Response Time
This S-Register determines how long the remote modem
carrier must be present on the telephone line before the
modem detects it and turns on Data Carrier Detect (DCD).
The longer the wait, the less likely that a false carrier
detection will occur due to noise on the line.
n = 1–255 (1/10 of a second).
Factory setting is 6 (0.6 seconds).
Issue 1 November 1994
4-21
AT Command Set and S-Registers
Table 4-2. S-Register Reference (3 of 6)
S-Register Description
S10=n
No Carrier Disconnect
This S-Register determines how long (in tenths of seconds)
the modem allows the carrier signal to be off before
disconnecting the call. This allows for a temporary loss of the
remote modem carrier without causing the local modem to
hang up. When set to 255, the modem will not disconnect
upon loss of the remote modem carrier.
n = 1–255 (1/10 of a second).
Factory setting is 14 (1.4 seconds).
S11=n
DTMF Tone Timer (ON)
This S-Register controls the length of the DTMF (touch tone)
ON time. This register is not used for pulse dialing.
n = 50–255 milliseconds.
Factory setting is 70ms.
S12=n
Escape Guard Time
This S-Register sets the value (in 20-millisecond increments)
for the required pause before and after the escape sequence
(+++) is issued.
Accepts a value from 0 to 255 in 20-millisecond increments.
Factory setting is 50 (1 second).
S14
Reserved.
S16
Reserved.
S18=n
Test Time-out
This S-Register sets the duration (in seconds) for any
modem loopback test issued by the &T command. After
timing out, the modem returns to Command mode. Setting
S18 to zero disables the modem test timer; the loopback test
must be terminated by issuing the appropriate escape
sequence followed by an ’AT&T0’ or ’ATH’ command.
0 = Disable
n = 0–255 (seconds). Factory setting is 0 seconds.
S21 – S23
4-22
Reserved.
Issue 1 November 1994
AT Command Set and S-Registers
Table 4-2. S-Register Reference (4 of 6)
S-Register Description
S25=n
DTR Detection
This S-Register defines the minimum amount of time that
DTR has to remain off (i.e., on-to-off-to-on transitions) before
the modem performs the function specified by ‘&Dn’
command. A change in DTR that persists for a shorter time
than the valued specified in S25 is ignored by the modem
(see the ‘&Dn’ command).
n = 0–255 (1/100 seconds).
Factory setting is 5 (50 msec).
S26 – S27
Reserved.
S30=n
Sleep Mode Timer
This S-Register determines when the modem enters sleep or
power-down mode. When enabled (S30
0), the modem
enters sleep mode whenever it has has been inactive for the
time delay specified by this S-Register. The modem is
considered to be in an inactive state when all of the following
three conditions are true:
1)
No internal processing is being performed.
2)
There is no activity between the computer and
the modem within the specified time period, n.
3)
The modem is off-line.
The modem exits sleep mode whenever the computer reads
or writes to the modem, or a ring signal is detected.
Sleep mode is disabled by setting S30 to a ‘0’.
n = 0–90 (seconds).
Factory setting is 10 seconds.
Issue 1 November 1994
4-23
AT Command Set and S-Registers
Table 4-2. S-Register Reference (5 of 6)
S-Register Description
S37=n
Maximum Allowable Data Rate
This S-Register selects the maximum allowable line speed.
For more information on this command, refer to Appendix D.
n = 0 DTE rate
n=3
300 bps
n=5
1200 bps
n=6
2400 bps
n=7
4800 bps
n=8
7200 bps
n=9
9600 bps
n = 10 12000 bps
n = 11 14400 bps
S90=n
Disconnect Inactivity Timer
This S-Register sets the length of time, in minutes, that the
modem will stay on-line/off-hook before disconnecting when
no data is transmitted or received. Any data transmitted or
received between the computer and the modem resets the
timer. A value is zero disables this feature.
n = 0–255 (minutes).
Factory setting is 0 (timer disabled).
4-24
Issue 1 November 1994
AT Command Set and S-Registers
Table 4-2. S-Register Reference (6 of 6)
S-Register Description
S108=n
Retrain Signal Quality Selector
This S-Register controls when the modem should retrain.
n=0
Never retrains.
n=1
Low Quality — retrains after a large number of data
errors.
n=2
Medium Quality — retrains after a number of data
errors.
n=3
High Quality — retrains after a few data errors.
For V.32 operation, the factory setting is 1 (Low Quality). For
V.32bis operation, the factory setting is 2 (Medium Quality).
S109=n
Permitted Line Speeds
This S-Register is used to select all permitted line speeds.
The value to enter for n is determined by adding the
appropriate weighting factor for each speed you want to
allow. The weights to use for each data rate are shown in the
following table:
Data Rate to be Allowed
4800 bps
7200 bps
9600 bps
12000 bps
14400 bps
Weighting Factor to Add
2
4
8
16
32
For example, if you only want to connect at 4800 bps, the
value to enter for n is 2. However, if you want to allow data
rates of 4800 bps and 12000 bps, the value to use for n is 18
(2 + 16).
For V.32 operation, the default setting is 10 – this value
allows 4800 bps and 9600 bps. (The other rates are not
support by V.32.)
For V.32bis operation, the default setting is 62 – this value
allows all rates (4800, 7200, 9600, 12000, and 14400 bps).
Issue 1 November 1994
4-25
Troubleshooting
A
This appendix points out basic problems that can occur when
operating a modem. It begins with simple actions and
progresses to more detailed reasons as to why your modem
may not operate. Use the hints provided in Tables A-1 through
A-5 to troubleshoot problems you may encounter.
You may have access to a Bulletin Board System (BBS) if there
is a BBS telephone number on your warranty card. If so, you
may use the BBS to view help text files which may contain more
recent troubleshooting information.
If you are experiencing problems while configuring your modem
to use it for the first time, refer to the PCMCIA installation
information in your PC’s documentation.
If you are still experiencing difficulty after trying the actions
suggested in this appendix, contact your modem or PC dealer.
Check your warranty card for more information on how to obtain
assistance. The first page (page A) of this User’s Guide
contains a place for recording customer support telephone
numbers.
Issue 1 November 1994
A-1
Troubleshooting
Table A-1. Modem Health
Symptom
Action
Modem does not
respond
Make sure the modem is properly seated in the
PCMCIA slot.
Make sure the PC is PCMCIA compliant.
Make sure the PC is turned ON.
Make sure that the COM port selected by the card
enabler on your PC is available and is not being used
by another device.
Reinstall the modem.
Use Table A-2 isolate problems with the connection between
your modem and computer. This table focuses on the modem
not accepting AT commands from the computer.
Table A-2. Modem — Computer Connection
Symptom
Action
Modem does not
accept or echo
back AT
commands
Make sure that the communications software has the
correct COM port selected.
Make sure that the IRQ setting for the COM port is not
being used by any other COM ports.
Make sure that the communications software is set to
the DTE speed allowed by the modem.
Make sure that all AT commands are terminated with
a carriage return.
Use your communications software to verify:
G that the computer has a valid character format.
Valid format consists of 8 data bits with no parity
or 7 data bits with even, odd, mark or space
parity.
G that the computer’s nominal data rate
(57,600 bps–300 bps) is supported by the
modem.
Issue the ATE1 command to make sure that
characters can be echoed back to your monitor. An
OK response should appear. Then, enter an AT and
carriage return to make sure characters display to
your monitor.
A-2
Issue 1 November 1994
Troubleshooting
Table A-3 provides some solutions to problems that can occur
when your modem tries to answer or originate a call.
Table A-3. Modem — Telephone Line Connection (1 of 4)
Action
Symptom
Modem does
not go off-hook
and answer an
incoming call
CONNECTION PROBLEMS —
Dial Environments in Answer mode
Make sure the modem and PCMCIA socket are
configured for modem operation.
Make sure the telephone cord is connected to the
telephone line connector and the modem.
Make sure the telephone line connector is properly
connected to the modem.
Attach a standard telephone to the wall telephone outlet
and verify that it rings during incoming calls. Also verify
that outgoing calls can be made.
Verify that the Auto-Answer Ring Count configuration
option (S-Register S0) is set to a value other than 0
(disable).
Verify that the computer is providing DTR to the modem.
Set the modem’s DTR Control to Ignore (&D0).
Modem goes
off-hook,
answers, but
does not
connect
Verify that the originating modem supports your
modem’s modulation schemes. The modem recognizes
CCITT V.32bis, V.32, V.22bis, V.22, Bell 212A, Bell 103J,
and V.23. Note that the modem does not support other
vendors’ proprietary modulation schemes.
Determine the originating modem’s modulation scheme,
and then force your modem to operate at the same
modulation scheme as the originating modem.
Try using different operating modes (\N). Start with \N4 and
attempt to answer a call. Try to answer a call after stepping
down to each \N setting (\N3, then \N2, etc.)
Perform a Local Analog Loopback test (&T1) and verify
that data entered at the computer is echoed back to the
computer.
Issue 1 November 1994
A-3
Troubleshooting
Table A-3. Modem — Telephone Line Connection (2 of 4)
Action
Symptom
Modem does
not go off-hook
and begin
dialing
CONNECTION PROBLEMS —
Dial Environments in Originate mode
Make sure the modem and PCMCIA socket are
configured for modem operation.
Make sure the telephone line connector is connected to
the modem. Make sure you are using a supported
telephone line connector.
If using AT Dialing, refer to the Table A-2, Modem —
Computer Connection.
When the modem goes off-hook, a dial tone should be
heard though the speaker. When the modem starts
dialing, the dial tone should stop as the touch-tone
signals (or dialing pulse) are sent. If the dial tone does
not break, check the setting of S11.
Refer to the Making a Call with Your Modem section in
Chapter 3 to verify that you are using the proper
command format.
Modem dials
but does not
connect
Determine if you are calling out through a PBX. If so, you
need to dial a 9 and comma before the telephone
number. You can check this by trying to dial the number
from a telephone.
Verify whether Tone or Pulse dialing is needed.
Make sure both modems are using the same or
compatible types of operating modem (check the \N
settings of both modems). Note that \N2, \N3, and \N4
will cause the modem to hang up if a compatible error
correction mode is not detected for the remote modem.
Try calling in Normal mode (\N0).
A-4
Issue 1 November 1994
Troubleshooting
Table A-3. Modem — Telephone Line Connection (3 of 4)
Action
Symptom
Intermittent
disconnects,
high error rates,
or excessive
retransmissions
CONNECTION PROBLEMS —
Dial Environments in Originate mode
Use the &T7 command to perform a remote digital
loopback test with pattern test.
Perform a local analog loopback with a Pattern test.
If your modem is operating in Direct mode (\N1), make
sure that the modem port flow control is disabled (\G0).
Your telephone may have Call Waiting enabled. Refer to
your local phone book for procedures to disable this
feature.
If the modem passes the above tests and a problem still
exists, then the problem is likely not with your modem.
High error rates
occur when
running a local
loopback or
self-test
Incoming rings can cause data errors during a loopback
test. Abort the test, disconnect the modular telephone
cord, and restart the test.
Modem does
not receive a
dial tone and
sends a NO
DIALTONE
message to
your computer
Make sure the telephone cord is connected to the
telephone line connector.
Attach a telephone directly to the wall outlet to verify that
a dial tone exists.
Disable the Dial Tone Detect configuration option (X0,
X1, and X3) and dial the telephone number. This will
force the modem to dial without detecting a dial tone on
the telephone line. This type of dialing is known as Blind
Dialing.
Issue 1 November 1994
A-5
Troubleshooting
Table A-3. Modem — Telephone Line Connection (4 of 4)
Action
Symptom
Modem
establishes and
disconnects a call
CONNECTION PROBLEMS —
Dial Environments in Originate mode
You may have a poor telephone line connection. Try
dialing again.
The remote modem may have encountered an error
control disconnect, where the modem is configured to
establish a call using error correction. If the modems
cannot negotiate error control, then a disconnect
occurs. Try using Normal mode(\N0).
Your telephone may have Call Waiting enabled. Refer
to your local phone book for procedures to disable
this feature.
Perform a Local Analog Loopback (&T1) test to check
the modem’s hardware operation.
A-6
Issue 1 November 1994
Troubleshooting
If the modems are having trouble passing data after connecting,
check the recommendations and solutions to this problem in
Table A-4.
Table A-4. Online Operation
Symptom
Action
Data is scrambled
Use your communications software to verify that the
character format (data bits, parity, and stop bits) is set
to the same value in both modems.
Missing data
during a transfer
Verify that you are using the same method of flow
control for both the modem and the computer
(RTS/CTS or XON/XOFF).
If using XON/XOFF flow control, verify that the
modem’s parity matches the computer’s parity.
Garbage
characters appear
on your monitor
when your modem
connects to
another modem
Your modem is not using error control and the other
modem is using error control. The garbage characters
are part of the error control handshaking sequence.
Verify that you are using the same method of flow
control for both the modem and the computer
(RTS/CTS or XON/XOFF).
Modem hangs up, Make sure that the &D2 command is set.
but does not
Make sure that the &C1 command is set so that when
indicate a hang up the CD signal turns Off, the modem hangs up.
Table A-5 focuses on problems you may experience during fax
operation.
Table A-5. Fax Operation
Symptom
Action
Modem cannot
send or receive a
fax
Make sure the modem and PCMCIA socket are
configured for modem operation.
Refer to the Fax Operation section of Chapter 3 or
your fax application software user’s guide for more
information.
Issue 1 November 1994
A-7
B
Table B-1 lists technical specifications for the KeepInTouch
Card modem.
Table B-1. Technical Specifications (1 of 2)
Specifications
Description
APPROVALS
FCC Part 15
FCC Part 68
DOC CS-03
REN
UL
CSA
See modem label for identification number
See modem label for registration number
See modem label for certification number
0.5B
Listed to UL 1950
Certified to CSA C22.2 No. 950
COMPATIBILITY
Dial-Line Modulations
Fax Modulations
ENVIRONMENT
Operating Temperature
Relative Humidity
Shock and Vibration
Storage Temperature
CCITT V.32bis (14,400, 12,000, 9600, 7200,
4800 bps)
CCITT V.32 (9600, 4800 bps)
CCITT V.22bis (2400 bps)
CCITT V.22 (1200 bps)
Bell 212A (1200 bps)
Bell 103J (300 bps)
CCITT V.17 (14,400, 12,000, 9600, 7200 bps)
CCITT V.29 (9600, 7200 bps)
CCITT V.27 ter (4800, 2400 bps)
0°C to 55°C
95% maximum
Withstands normal shipping and handling
–20°C to +65°C
Issue 1 November 1994
B-1
Technical Specifications
Table B-1. Technical Specifications (2 of 2)
INTERFACES
PC Connection
68-pin PCMCIA Type II connector
Telephone Line
Connection
2-pin telephone line connector
(RJ11C in USA, CA11A in Canada)
4 pin connector (reserved for future use)
DIMENSIONS
Height
Width
Length
0.196 inches (5.0 mm)
2.126 inches (54.0 mm)
3.370 inches (85.6 mm)
TRANSMIT LEVEL
Dial Line
Permissive
DATA RATES
Dial Line
Computer Data Rates
ERROR CONTROL
14,400, 12,000, 9600, 7200, 4800, 2400, 1200,
or 300–0 bps.
57,600, 38,400, 19,200, 14,400, 9600, 7200,
4800, 2400, 1200, 300 bps.
CCITT V.42 and MNP 2–4
DATA COMPRESSION CCITT V.42bis and MNP 5
B-2
Issue 1 November 1994
C
Response codes are informational messages sent from the
modem and displayed on your monitor. These messages are the
modem’s response to commands you have sent to the modem.
They can inform you of the status of a call (Ring, No Answer), or
whether or not a command is valid (OK, Error), or whether or
not the modem has connected using error control (Connect
14,400 REL-MNP).
The KeepInTouch Card modem ships from the factory
configured to use the word format. If your computer requires
that you use the numbers format instead, refer to the V
command on page 4-6.
The Q command is used to enable and disable the reporting of
any response codes from the modem. When Q0 is set so that
response codes are enabled, the list of response codes reported
by the modem depends on the settings of the X and \V
commands. A summary of how X and \V affect the response
codes reported by the modem is shown in Table C-1.
Issue 1 November 1994
C-1
Response Codes
Table C-1. Response Codes Enabled by X and \V Command
Dial Tone
Detection
Busy Tone
Detection \V0
\V1
\V2
X0 Disabled
Disabled
0–4
0–4
0–4
X1 Disabled
Disabled
0–5, 10–17
0–5, 10–17,
22–30
0–5, 10–17,
32–70
X2 Enabled
Disabled
0–6, 10–17
0–6, 10–17,
22–30
0–6, 10–17,
32–70
X3 Disabled
Enabled
0–5, 7,
10–17
0–5, 7,
10–17,
22–30
0-5, 7
10–17,
32–70
X4 Enabled
Enabled
0–7, 10–17
0–7, 10–17,
22–30
0–7, 10–17,
32–70
Table C-2 describes the response codes supported by the
KeepInTouch Card modem.
Table C-2. Basic Response Codes (\V0) (1 of 2)
Numeric
Format
Word Format
Description
0
OK
Command Executed
1
CONNECT
Modem connect to line
2
RING
Modem receiving a ring voltage from the
line
3
NO CARRIER
Modem lost carrier signal, does not detect
carrier signal, or does not detect answer
tone
4
ERROR
Invalid command
5
CONNECT 1200
Connection at 1200 bps
6
NO DIAL TONE
No dial tone detected
7
BUSY
Busy or trunk busy signal detected
8
NO ANSWER
No answer
10
CONNECT 2400
Connection at 2400 bps
11
CONNECT 4800
Connection at 4800 bps
12
CONNECT 7200
Connection at 7200 bps
14
CONNECT 9600
Connection at 9600 bps
16
CONNECT 12000 Connection at 12,000 bps
C-2
Issue 1 November 1994
Response Codes
Table C-2. Basic Response Codes (\V0) (2 of 2)
Numeric
Format
Word Format
17
CONNECT 14400 Connection at 14,400 bps
+F4
+FCERROR
Description
Error in sending or receiving a fax.
(Invalid tone detected.)
Tables C-3 and C-4 list the response codes which can be turned
on by using the \V1 and \V2 commands, respectively.
Table C-3. Modified Response Codes (\V1)
Numeric Format
Word Format
22
CONNECT 300/REL
24
CONNECT 1200/REL
25
CONNECT 2400/REL
26
CONNECT 4800/REL
27
CONNECT 7200/REL
28
CONNECT 9600/REL
29
CONNECT 12000/REL
30
CONNECT 14400/REL
Issue 1 November 1994
C-3
Response Codes
Table C-4. V.42 Extended Response Codes (\V2)
Numeric Format
Word Format
32
CONNECT 300/REL–MNP
34
CONNECT 1200/REL–MNP
35
CONNECT 2400/REL–MNP
36
CONNECT 4800/REL–MNP
37
CONNECT 7200/REL–MNP
38
CONNECT 9600/REL–MNP
39
CONNECT 12000/REL–MNP
40
CONNECT 14400/REL–MNP
42
CONNECT 300/REL–MNP 5
44
CONNECT 1200/REL–MNP 5
45
CONNECT 2400/REL–MNP 5
46
CONNECT 4800/REL–MNP 5
47
CONNECT 7200/REL–MNP 5
48
CONNECT 9600/REL–MNP 5
49
CONNECT 12000/REL–MNP 5
50
CONNECT 14400/REL–MNP 5
54
CONNECT 1200/REL–LAPM
55
CONNECT 2400/REL–LAPM
56
CONNECT 4800/REL–LAPM
57
CONNECT 7200/REL–LAPM
58
CONNECT 9600/REL–LAPM
59
CONNECT 12000/REL–LAPM
60
CONNECT 14400/REL–LAPM
65
CONNECT 2400/REL–LAPM V.42 BIS
66
CONNECT 4800/REL–LAPM V.42 BIS
67
CONNECT 7200/REL–LAPM V.42 BIS
68
CONNECT 9600/REL–LAPM V.42 BIS
69
CONNECT 12000/REL–LAPM V.42 BIS
70
CONNECT 14400/REL–LAPM V.42 BIS
C-4
Issue 1 November 1994
D
Changing Modem-to-Modem
Connection Data Rates
Your modem is capable of communicating with other modems at
data rates of 300, 1200, 2400, 4800. 7200. 9600. 12000, or
14400 bits per second (bps). When you place a call to another
modem, the settings of two AT commands (B and N) and two
S-Registers (S37 and S109) are used to determine the data rate
of that connection.
S-Register S37 is used to set the maximum allowable data rate.
S-Register S109 is used to select all the permitted data rates.
The B command is used to select whether the modem is
configured as a CCITT or BELL modem. The N command is
used to select whether the modems may connect only at a
single data rate (N0), or whether the modems may connect at a
lower data rate (N1).
When the N0 command is used, the modems can only connect
if the answering modem supports the data rate specified in
S-Register S37 of the originating modem (the one which places
the call). If the answering modem cannot support the data rate
specified by the originating modem, no connection will be made.
When the N1 command is used (the default setting from the
factory), the modems will first attempt to connect at the data
rate specified by S37. but will fall back to a lower data rate if
required by the receiving modem.
If you would like to know more about how the modem uses
modulations and data rates, refer to the information on the B
and N commands and S-Registers S37 and S109 in Chapter 4.
Issue 1 November 1994
D-1
Advanced Modem Concepts
Error Control
Error control guarantees that data sent and received between
your modem and the remote modem arrives with 100%
accuracy. This is a much welcomed function since you can
never guarantee the quality of the telephone line you are using.
Your modem uses the CCITT standard V.42 (pronounced
vee-dot 42) and MNP 2–4 error control protocols. These
protocols make sure that errors are eliminated even if it means
retransmitting certain portions of data. This process occurs
between the modems and is completely transparent to you.
Once your modem is online, it negotiates error control and, if
enabled, data compression (discussed in the next section).
Five operating modes, selectable by the \N command, are
supported to allow your modem to communicate with remote
modems that may or may not support error correction and data
compression.
NOTE:
If one modem is configured for error control and the other
modem is not, the non-error control modem’s monitor may
display “garbage” characters immediately after
connecting. This is normal since the non-error control
modem interprets these characters as data instead of part
of the error control handshaking process.
D-2
Issue 1 November 1994
Advanced Modem Concepts
Data Compression
Data compression minimizes the amount of data sent over the
telephone line by removing redundant information, thereby
compressing the data it receives from the computer. To do this,
the modem uses the V.42bis or MNP 5 data compression
protocols. Once a file is compressed, it can be sent faster
across the telephone line since there is less data to send. Once
the file is received by the other modem, the file is decompressed
to its original form before being sent to its attached computer.
The amount of data compression achieved is dependent on the
type of file being transferred. The more repetitive the data, the
more compressible it is.
Data compression is useful when transferring uncompressed
files. However, if the MNP protocol is used, and the file has
been compressed by PC software, such as PKUNZIPr, prior to
the transfer, then data compression should be turned Off. Use
the %C command to turn data compression ON or Off.
The format for the command which controls data compression
is:
TYPE:
AT%Cn
where n is 0 for disable and 1 for enable.
Flow Control
Flow control is a method of stopping and starting data flow
between two devices. This prevents one device from accepting
so much data from another that its buffer (a temporary storage
area) fills and then overflows resulting in data loss or errors.
Flow control can occur between a modem and computer or
between two modems or between two computers. The following
sections use Figures D-1 and D-2 to help illustrate various
methods of flow control.
Issue 1 November 1994
D-3
Advanced Modem Concepts
Modem-to-Computer Flow Control
Often, your computer is able to send data to your modem faster
than the modem can transmit it across the telephone line. As a
result, the modem’s buffer begins to fill with data received from
the computer. To prevent the buffer from filling and overflowing,
which would result in data loss and errors, the modem tells the
computer to stop sending data.
When the modem’s buffer is almost full (usually 80%), it tells the
computer to stop sending data as illustrated in Figure D-1. Once
the modem has a chance to transmit its buffered data, it tells the
computer to continue sending data.
Figure D-1. Modem-to-Computer Flow Control
To do this, the modem can use either software characters
(XON/XOFF) embedded in the data stream or hardware
signals (CTS/RTS) on the serial connector to control data flow.
The \Q command lets you determine which flow control method
the modem uses to stop data from the computer, as well as
which method the computer uses to stop data from the modem.
In some situations, the computer can stop data flow from the
modem as illustrated in link A—B of computer-to-modem flow
control in Figure D-2. In this instance, if Computer A’s buffer
begins to fill, it can stop data flow by sending an XOFF to
Modem B or by lowering its RTS signal to Modem B.
D-4
Issue 1 November 1994
Advanced Modem Concepts
In turn, Modem B can use V.42 or MNP flow control techniques
(if using error control), or it can send an XOFF to Modem C to
stop data flow (if using modem-to-modem flow control). This is
illustrated in link B—C of computer-to-modem flow control in
Figure D-2.
If Modem C’s buffer begins to fill because of data sent from
Computer D, Modem C stops data flow either by issuing an
XOFF or by lowering its CTS signal to Computer D. This is
illustrated in link C—D of computer-to-modem flow control in
Figure D-2. Computer D then stops sending data to Modem C
resulting in a halt of all data transfer between Computer A and
Computer D.
Computer-to-Computer Flow Control
Flow control can be handled by the two computers. In this case,
if Computer A’s buffer begins to fill, it can stop data flow by using
an XOFF character to Computer D (see computer-to-computer
flow control in Figure D-2). In this situation, the modems are
configured to ignore and pass through any XON/XOFF
characters they may receive. To resume data flow, Computer A
issues an XON character.
For this type of flow control, the computers are normally
configured for XON/XOFF flow control, and the modems are
configured for XON/XOFF flow control (\Q command) with
XON/XOFF Passthrough enabled (refer to the \X command).
Issue 1 November 1994
D-5
Advanced Modem Concepts
Figure D-2. Various Flow Control Methods
Modem-to-Modem Flow Control
Finally, flow control can occur between two modems. If
Modem B’s buffer begins to fill, and error control is disabled, it
can issue an XOFF to Modem C (see modem-to-modem flow
control in Figure D-2). In turn, Modem C will tell Computer D to
stop sending data. Data flow can be resumed by Modem B
issuing an XON to Modem C.
In this case, the modems are normally configured for
XON/XOFF flow control and have modem-to-modem flow
control enabled (see the \G command).
D-6
Issue 1 November 1994
Glossary
A
Active Profile
A nonvolatile configuration area containing the most recently
saved configuration options. Any changes made to configuration
options can be saved by issuing a &W command.
analog signal
A type of signal used to transmit data over telephone lines.
Answer mode
The modem is in a state where it is ready to receive an incoming
call. For example, an ATA (Answer) command has been issued
to place the modem into online answer mode. The modem has
been forced off-hook and is generating an answer tone,
beginning the handshaking process with the calling modem.
asynchronous transmission
A data transmission that is synchronized by a transmission start
bit at the beginning of a character (five to eight bits) and one or
more stop bits at the end.
AT command set
A group of commands, issued from an asynchronous computer,
that allows control of the modem while in Command mode. All
commands must begin with the characters AT and end with a
carriage return.
AT command string
This consists of several AT commands issued at once. The
string is preceded with an AT prefix.
Issue 1 November 1994
GL-1
Glossary
autobaud
Modem automatically determines the asynchronous computer
data rate when using AT commands.
B
Bell 103J
An AT&T Bell standard for 300 bps data transmission.
Bell 212A
An AT&T Bell standard for 1200 bps data transmission.
bps
Bits per second. Indicates the speed at which data is transmitted
between devices.
buffer
A storage area used to compensate for differences in data flow
rate when transmitting data from one device to another.
C
CD
Carrier Detect. A signal between the local and remote ends of a
network indicating energy exists on the transmission circuit.
command line
Contains the command(s) instructing the modem to perform a
function. Command lines begin with the AT prefix, and are
executed when you press the Enter key.
GL-2
Issue 1 November 1994
Glossary
Command mode
One of two modem operating modes. When in Command mode,
the modem accepts commands instead of transmitting or
receiving data. See also Data mode.
COM port
Communications port. A computer’s serial communications port
used to transmit to and receive data from a modem. The
modem connects directly to this port.
communications software
Software installed on a computer that controls the modem.
configuration option
Modem software that sets specific operating parameters for the
modem. Sometimes referred to as straps.
CTS
Clear-to-Send. A signal sent to the computer indicating that the
modem is ready for the computer to transmit data.
D
data compression
The elimination of empty fields, redundancies, and gaps in order
to reduce storage capacity needs and the amount of data to be
transmitted. Anything that is eliminated is restored after the data
is received.
Data mode
One of two operating modes. When in Data mode, the modem
considers any input from the computer to be data and transmits
it across the telephone line to the remote modem. See also
Command mode.
Issue 1 November 1994
GL-3
Glossary
data rate
The speed at which data is transferred over the telephone line.
This rate is measured in bits per second.
DCE
Data Communications Equipment. A modem.
dial command modifiers
A modifier used in the dial string that instructs the modem how
to process a dialed telephone number.
dial string
A series of characters that consists of numbers and modifiers
used to dial a telephone number.
digital signal
A signal used to transfer data between a locally attached
computer and modem.
download
A file transfer in which a file is received from another computer.
DSR
Data Set Ready. A signal from the modem to the computer that
indicates the modem is turned on and connected to the
computer.
DTE
Data Terminal Equipment. The equipment that provides or
creates data. In this guide, the term DTE refers to the computer
in which the modem is installed.
DTR
Data Terminal Ready. A signal from the computer to the modem
that indicates the computer is turned on and connected to the
modem.
GL-4
Issue 1 November 1994
Glossary
E
error control
A method used by the modem to detect and correct data
transmission errors.
escape sequence
Default setting is +++. This sequence lets you switch your
modem from Data mode to Command mode.
extended result codes
An asynchronous message (in either numbers or words) that
includes VF data rate and error control information the modem
sends to the computer after executing or trying to execute a
command.
F
factory defaults
A predetermined set of configuration options containing the
optimum settings for operation on asynchronous dial networks.
fax software
Software installed on a computer that allows a modem to send
and receive facsimiles from another fax modem or fax machine.
flow control
A process in which devices stop and start the flow of data in a
network to avoid losing data.
Issue 1 November 1994
GL-5
Glossary
H
handshaking
The exchange of predetermined codes and signals (tones) to
establish a connection between two modems. The handshaking
process occurs when the two modems connect, and then spend
a brief period deciding how they will transfer data, the speed of
the transfer, and if error control will be used. This is usually
identified by the high-pitched tones emitted by your modem.
I
idle state
A state in which the modem’s configuration options can be
modified or commands can be issued to the modem using
AT commands.
L
loopback test
Any test that verifies the integrity of a device by sending data
from one device to another, and then checking the received data
for errors. Various loopback tests can be used to isolate a
problem to the computer, modem, or telephone line.
GL-6
Issue 1 November 1994
Glossary
M
MNP
Microcom Networking Protocol. Levels 2—4 of this protocol
detect and correct data errors caused by poor telephone line
conditions. Level 5 includes data compression.
modem
MOdulator/DEModulator. A device used to convert data from a
digital signal to an analog signal so that data can be transmitted
over a telephone line. Once the data is received, the analog
signal is converted back into a digital signal.
modem port
The modem port is the connection between the modem and the
telephone line.
modulation
A modem modulation is a set of guidelines that determines
how the modems connect and at what speed they communicate.
Modulations, such as V.32bis, V.32, V.22bis, V.22, Bell 212A,
and Bell 103, have a maximum and minimum data rate. See
also data rate.
N
Nonvolatile
This term describes memory which does not lose its contents
when the device is powered down. Modem options are saved in
nonvolatile memory when you use the &W command.
Issue 1 November 1994
GL-7
Glossary
O
off-hook
A telephone or modem is being used.
on-hook
A telephone or modem is not being used.
Originate mode
The modem is in a state where it is ready to transmit a call. In a
dial network, it is the modem that makes the call.
P
parity
A way of checking data accuracy by counting the number of bits
that have a value of one.
PBX
Telephone switching equipment (Private Branch Exchange)
dedicated to one customer. A PBX connects private telephones
to each other and to the public dial network.
PCMCIA
Personal Computer Memory Card International Association.
Standard used to define the physical and operational
characteristics of a ‘‘credit card” device.
protocol
The rules for timing, format, error control, and flow control during
data transmission.
GL-8
Issue 1 November 1994
Glossary
pulse dialing
One of two dialing methods, in which telephone numbers are
sent as pulses (brief changes in voltage or current intensity)
across the telephone line. Rotary telephones use pulse dialing.
R
register
A part of the modem’s memory that contains values that
determine the modem’s operating characteristics.
result code
An asynchronous message (in either numbers or words) that the
modem sends to the computer after executing or trying to
execute a command.
RAM
Random Access Memory. Read/Write memory which is volatile
(loses its contents when the device is powered down). The
modem uses this type of memory to buffer (temporarily store)
data.
ROM
Read Only Memory. This is nonvolatile memory which cannot be
written to. The modem’s operational firmware is stored in this
type of memory.
RTS
Request-to-Send. A signal from the computer to the modem that
states the computer has data to send.
RXD
Receive Data. A signal that is used by the computer to receive
data from the modem. Conversely, the modem uses TXD to
transmit data to the computer.
Issue 1 November 1994
GL-9
Glossary
S
S-Registers
Registers that contain information affecting the modem
parameters. All S-Registers must be preceded by the AT prefix.
serial port
The serial port is the connection between the PC and its
attached modem.
synchronous transmission
Data transmission that is synchronized by timing signals.
Characters are sent at a fixed rate. This type of transmission is
more efficient than asynchronous transmission.
T
tone dialing
One of two dialing methods, in which telephone numbers are
sent as tones across the telephone lines.
training
A process where two modems try to establish a connection over
the telephone line.
TXD
Transmit Data. A signal that is used by the computer to transmit
data to the modem. Conversely, the modem uses RXD to
receive data from the computer.
GL-10 Issue 1 November 1994
Glossary
U
upload
A file transfer in which you send a file to another computer.
User Profile 0
A user-defined configuration area containing customized
configuration options for a specific application.
User Profile 1
A user-defined configuration area containing customized
configuration options for a specific application.
V
Volatile
This term describes memory which loses its contents when the
device is powered down. See also RAM.
V.17
A standard for modems operating in fax mode, full-duplex with
asynchronous or synchronous data at 14,400 bps over dial
telephone lines.
V.22
A standard for modems operating full-duplex with asynchronous
or synchronous data at 1200 bps over dial telephone lines.
V.22bis
A standard for modems operating full-duplex with asynchronous
or synchronous data at 2400 or 1200 bps over dial telephone
lines.
Issue 1 November 1994 GL-11
Glossary
V.23
A standard for modems operating with asynchronous or
synchronous data at 1200 or 600 bps over dial or leased
telephone lines
V.32
A standard for modems operating full-duplex with asynchronous
or synchronous data at 9600 or 4800 bps on dial or leased
telephone lines.
V.32bis
A standard for modems operating full-duplex with asynchronous
or synchronous data over dial or leased telephone lines at
14,400, 12,000, 9600, 7200, or 4800 bps.
V.42
A standard for error control protocol.
V.42bis
A standard for data compression.
X
XOFF
A character that tells the computer or modem to stop
transmitting data.
XON
A character that tells the computer or modem to start or resume
transmitting data
GL-12 Issue 1 November 1994
Index
A
Active User Profile, 3-9
answering a call, 3-8
AT Commands.
+++ (escape sequence), 3-9,
4-2
A/ (repeat last command), 4-2
A (answer), 4-2
B (CCITT/Bell Mode), 4-2, D-1
C (carrier control option), 4-2
D (dial), 3-4, 4-3
E (command character echo),
4-4
F (on-line echo), 4-4
H (hook), 3-7, 4-4
I (identification/Checksum), 4-4
M (speaker on/off), 4-4
N (select data rate handshake),
4-5, D-1
O (return to online data mode),
4-5
P (pulse dial), 4-5
Q (response codes), 4-5, C-1
S (change/display S-register),
4-5
Sn? (view S-register), 4-6
T (tone dial), 4-6
V (response codes format), 4-6,
C-1
X (ext. result codes, dial tone
detect, busy tone detect),
4-7, C-1
Z (reset and load stored profile),
3-12, 4-8
\A (maximum frame size), 4-8
\B (transmit break), 4-8
\C (set auto-reliable mode), 4-9
\G (modem port flow control),
4-9
\J (BPS rate adjustment), 4-10
\K (set break control), 4-10
\N (set operating mode), 4-12
\Q (flow control of computer and
modem), 3-14, 4-12
\T (set inactivity timer), 4-13
\V (change response code set),
4-13, C-1
\X (XON/XOFF passthrough
flow control), 4-13
&D (Data Terminal Ready
control), 3-7, 4-14
&C (data carrier detect control),
4-13
&F (load factory defaults), 3-11,
4-14
&G (guard tone), 4-14
&P (dial pulse ratio), 4-15
&S (data set ready control), 4-15
&T (tests), 4-15, A-5, A-6
&U (disable Trellis Coding), 4-16
&V (view active and user
profiles), 3-10, 3-12, 4-7,
4-16
&W (write/save changes to
memory), 3-10, 4-17
&Y (load a user profile on
power-up), 3-9, 4-17
&Z (store telephone numbers),
3-6, 4-3, 4-17
%A (set auto-reliable fallback
character), 4-18
%C (MNP 5 data compression),
4-18
%E (auto-retrain control), 4-18
%G (auto-fall forward/fall back
control), 4-18
%Q (line signal quality), 4-18
–C (generate data modem
calling tone), 4-19
–J (set V.42 detect phase), 4-19
”H (V.42bis compression
control), 4-19
”O (V.42bis string length), 4-19
guidelines for use, 3-3
auto-reliable mode, 4-9, 4-12, 4-18
Issue 1 November 1994
IN-1
Index
B
blind dialing, 4-21
bulletin board system, 1-3, A-1
busy tone, 4-7
error correction, 4-16, D-2
escape guard time, 3-2
escape sequence (+++), 3-2, 3-9,
4-2, 4-20
examples of dial command strings,
3-6
F
C
Card and Socket Services, 1-3,
2-3
COM port, 2-3, A-2
command mode, 3-2, 3-3, 3-9
command strings, 3-4
communications software, 1-3
factory settings, 3-11, 4-1
fax, 1-3, 2-3, 3-14, A-7
file transfers, 3-13
flow control, 4-9, 4-12, 4-13, A-7,
D-3
H
D
hanging up, 3-7
data carrier detect, 4-13, 4-21
data compression, 4-18, 4-19, D-3
data mode, 3-2, 3-9
data rates, GL-7
dial modifiers, 3-5, 4-3
dial tone, 4-7
direct mode, 4-11, 4-12
disconnecting a call, 3-7
DTR, 3-7, 3-8, 4-23
DTR disconnect, 3-7
I
installation, 2-1
IRQ setting, 2-3, A-2
L
line signal quality, 4-18
long distance dialing, 3-7
E
equipment
required, 1-3
supplied, 1-2
error control, D-2
M
modem port, 4-10
modulations, A-3, B-1
IN-2
Issue 1 November 1994
Index
N
normal mode, 4-12, A-6
O
online command mode, 3-2, 3-3
operating modes, 4-12
P
PBX, 3-6
S25 ( DTR detection), 4-23
S3 (carriage return character),
4-20
S30 (Sleep Mode Timer), 4-23
S4 (line feed character), 4-20
S5 (backspace character), 4-20
S6 (blind dial pause time), 4-21
S7 (no answer time out), 4-21
S8 (pause time for dial modifier),
4-21
S9 (Carrier Detect response
time), 4-21
S90 (Disconnect Inactivity
Timer), 4-24
S37 (Maximum allowable data
rate), 4-24, D-1
serial port, 4-10
serial port – definition, GL-10
serial port speed, 4-10
sleep mode, 4-23
R
reliable mode, 4-11, 4-12
removing the modem, 2-2
response codes, 3-2, 3-4, 4-7, C-1
S
S-Registers, 3-3
S0 (auto-answer ring number),
3-8, 3-14, 4-20
description, 4-1
S1 (Ring Count), 4-20
S10 (loss of carrier disconnect),
4-22
S108 (Retrain Signal Quality
Selector), 4-25
S109 (Permitted Line Speeds),
4-25, D-1
S11 (DTMF tone timer ON), 4-22
S12 (escape guard timer), 4-22
S18 (test time-out), 4-22
S2 (AT escape character), 4-20
T
technical specifications, B-1–B-4
technical support telephone
number, 1-3
testing your modem, 4-15
troubleshooting, A-1–A-11
tutorials.
answering a call, 3-8
changing modem settings, 3-9
changing modulation and
speed, D-1
making a call, 3-4
operating modes, 3-2
sending files and faxes, 3-12
disconnecting a call, 3-7
using the escape sequence, 3-9
U
user profiles, 3-9, 3-10, 4-8, 4-16,
4-17
Issue 1 November 1994
IN-3
">