Multi-Tech Systems MT3334HD8 User Manual
MT3334HD8 Modem
User Guide
MT3334HD8 User Guide
P/N 82063701, Revision B
Copyright © 1997 by Multi-Tech Systems, Inc.
All rights reserved. This publication may not be reproduced, in whole or in part, without prior expressed
written permission from Multi-Tech Systems, Inc.
Multi-Tech Systems, Inc. makes no representation or warranties with respect to the contents hereof and
specifically disclaims any implied warranties of merchantability or fitness for any particular purpose.
Furthermore, Multi-Tech Systems, Inc. reserves the right to revise this publication and to make changes
from time to time in the content hereof without obligation of Multi-Tech Systems, Inc., to notify any
person or organization of such revisions or changes.
Revision Date Description
A
B
3/31/97
5/29/97
Manual released.
Manual updated.
Multi-Tech, CommPlete, RASExpress, MultiExpress, MultiExpress Fax MultiModem, MultiModemZDX,
MultiModemManager, and the Multi-Tech logo are trademarks of Multi-Tech Systems, Inc. Other
trademarks and trade names mentioned in this publication belong to their respective owners.
Multi-Tech Systems, Inc.
2205 Woodale Drive
Mounds View, Minnesota 55112
(612) 785-3500 or (800) 328-9717
U.S. Fax (612) 785-9874
Technical Support (800) 972-2439 or Email to: tsupport@multitech.com
Internet Address: http://www.multitech.com
Federal Communications Commission Statement
This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant
to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful
interference when the equipment is operated in a commercial environment. This equipment generates,
uses, and can radiate radio frequency energy, and if not installed and used in accordance with the
instruction manual, may cause harmful interference to radio communications. Operation of this
equipment in a residential area is likely to cause harmful interference, in which case the user will be
required to correct the interference at his own expense.
Warning: Changes or modifications to this unit not expressly approved by the party responsible for
compliance could void the user’s authority to operate the equipment.
FCC Regulations for Telephone Line Interconnection
1. No repairs are to be made by you. Repairs are to be made only by Multi-Tech Systems or its
licensees. Unauthorized repairs void registration and warranty. Contact Multi-Tech Systems, Inc. for
details of how to have repairs made.
2. When trouble is experienced, you must disconnect your modem from the telephone company’s jack
to determine the cause of the trouble, and reconnect your modem only when the trouble is
corrected.
3. The modem cannot be connected to pay telephones or party lines.
4. If requested by the telephone company, you must notify them of the following before the
MT3334HD8 is installed:
a. The particular phone line (phone number) to which the connection is to be made.
b. The FCC Registration Number:
AU7USA-24457-DE-N
c. The manufacturer’s name and model number:
Multi-Tech Systems - Model CC9600 CommPlete Communications Server
5. If the telephone company notifies you that your device is causing harm, unplug it. The telephone
company may disconnect your service if necessary and also may change its facilities, equipment,
operations or procedures which may affect operation of your equipment. Where practical, the
telephone company must promptly inform you in writing of the temporary disconnect or change in
service, give you the opportunity to make changes allowing uninterrupted service, and inform you of
your rights to bring a complaint to the FCC.
CommPlete Communications Server iii
FCC Fax Warning
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 page or 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 or such business, other entity, or individual.
See your fax software manual for setup details.
Canadian Limitations Notice
Notice: The ringer equivalence number (REN) assigned to each terminal device provides an indication of
the maximum number of terminals allowed to be connected to a telephone interface. The termination of
an interface may consist of any combination of devices subject only to the requirement that the sum of the
ringer equivalence numbers of all the devices does not exceed 5.
Notice: The Industry Canada label identifies certificated equipment. This certification means that the
equipment meets certain telecommunications network protective, operational and safety requirements.
Industry Canada 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. 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 lines and internal metallic water pipe system, if present, are connected together. This precaution
may be particularly important in rural areas.
Caution: Users should not attempt to make such connections themselves, but should contact the
appropriate electric inspection authority, or electrician, as appropriate.
iv CommPlete Communications Server
v
Table of Contents
1 Introduction
Introduction ...................................................................................................................................................... 2
LED Indicators................................................................................................................................................... 2
Power Supply ..................................................................................................................................................... 2
Manual Organization......................................................................................................................................... 3
Technical Specifications .................................................................................................................................... 6
2 Installation
Introduction ...................................................................................................................................................... 8
Safety Warnings................................................................................................................................................. 8
Pre-Installation Notes ....................................................................................................................................... 9
Installation Procedure....................................................................................................................................... 9
3 AT Commands
Working with AT Commands ..........................................................................................................................12
Modes of Operation .....................................................................................................................................12
Command Structure ....................................................................................................................................12
Command Editing........................................................................................................................................13
Dialing Commands...........................................................................................................................................16
Dial Modifier Commands.................................................................................................................................16
Phone Number Memory Commands...............................................................................................................19
Configuration Storage and Recall Commands.................................................................................................20
Modem Response (Result Code) Commands..................................................................................................21
Online Connection Commands ........................................................................................................................24
V.34 Commands ...............................................................................................................................................28
RS-232 Interface Commands ...........................................................................................................................29
Error Correction and Data Compression Commands .....................................................................................31
Speed Conversion Commands .........................................................................................................................33
Immediate Action Commands .........................................................................................................................35
Flow Control Commands .................................................................................................................................36
Escape Sequences .............................................................................................................................................39
Remote Configuration Commands ..................................................................................................................40
Line Probe Commands.....................................................................................................................................41
Diagnostic Commands .....................................................................................................................................42
4 S-Registers
Introduction .....................................................................................................................................................46
S-Registers ........................................................................................................................................................46
Reading and Assigning S-Register Values .......................................................................................................51
Examples of Assigning Values.....................................................................................................................51
Examples of Reading Values .......................................................................................................................51
AT Commands that Affect S-Registers ............................................................................................................51
CommPlete Communications Server
5 Testing the MT3334HD8
Introduction .....................................................................................................................................................54
Local Analog Loopback Test (V.54 Loop 3) .................................................................................................... 54
Remote Digital Loopback Test (V.54 Loop 2) .................................................................................................55
Local Digital Loopback Test (V.54 Loop 2) .....................................................................................................57
6 Warranty, Service, and Technical Support
Limited Warranty.............................................................................................................................................60
Service...............................................................................................................................................................61
Technical Support ............................................................................................................................................61
Recording Product Information .................................................................................................................61
The Multi-Tech BBS .........................................................................................................................................62
Logging onto the Multi-Tech BBS ...............................................................................................................62
Downloading a File ......................................................................................................................................62
Reading a Message.......................................................................................................................................63
Leaving a Message .......................................................................................................................................63
Bulletins .......................................................................................................................................................63
About CompuServe ..........................................................................................................................................63
About the Internet............................................................................................................................................64
About the Multi-Tech Fax-Back Service ..........................................................................................................64
Upgrading the MT3334HD8 Firmware............................................................................................................ 65
Using FlashPro to Upgrade Firmware ........................................................................................................65
Appendix A ASCII Conversion Chart....................................................... 68
Appendix B Dial Pulses and Tones...........................................................69
Appendix C Result Code Summary...........................................................71
Appendix D S-Register Summary ................................................................73
Appendix E AT Command Summary....................................................... 75
Appendix F Remote Configuration.............................................................85
Index .........................................................................................................................................................87
vi CommPlete Communications Server
1 Introduction
CommPlete Communications Server 1
MT3334HD8 User Guide
Introduction
The Multi-Tech MT3334HD8 is a high speed, high density modem card for the CommPlete
Communications Server. Each MT3334HD8 card contains eight integrated 33,600 bps modems. Each
modem on the MT3334HD8 card can be configured independently of the others via the CommPlete
Communications Server’s MR9600 controller, which can support and control up to 12 cards per rack.
Users dial into the MT3334HD8’s modems through a T1 daughter card on the RASCard that controls the
segment. There are no external connectors on the MT3334HD8.
Up to three MT3334HD8 cards can be installed per T1 segment. With eight modems per card, the
CommPlete Communications Server can support up to 24 simultaneous data lines per segment, or 96 per
CommPlete Communications Server
The MT3334HD8 operates as an enhanced ITU-T V.34 dial-up modem with a maximum speed of 33,600
bits per second (bps). As such, it includes the advanced features of Multi-Tech standalone modems such as
the popular MultiModemZDXb.
The MT3334HD8 is registered by the FCC for direct connection to the public telephone networks. No Data
Access Arrangements (DAAs) are required.
The MT3334HD8 is fully compatible with the standard AT command set, and is therefore compatible with
all popular communications software packages.
This user guide will help you to install, configure, test, and use the MT3334HD8.
LED Indicators
The MT3334HD8 has 16 LED indicators on the front panel, two for each modem:
CD Carrier Detect. The CD LED lights when the modem detects a valid carrier signal.
OH Off Hook/Out of Service. The OH LED lights when the modem is off hook, which occurs when the
modem is dialing, online, or answering a call. The LED flashes when the modem is in the busy-out
or out-of-service state.
Power Supplies
DC voltages are supplied to all modems in the CC9600 rack through two PS9600 universal input switching
power supplies designed for conventional 115 or 230 VAC input. The power supplies are designed for
redundant, fail-safe operation. If one should fail, the other can supply the power requirements of the entire
CommPlete Communications Server. Each PS9600 power supply has one LED indicator that indicates the
presence of all supply voltages.
Manual Organization
Chapter 1 Introduction
This chapter describes the MT3334HD8 and its LED indicators, gives its technical specifications, and
provides a guide to the organization of the manual.
2 CommPlete Communications Server
1 Introduction
Chapter 2 Installation
This chapter describes how to install the MT3334HD8 into the CC9600 chassis.
Chapter 3 Command Mode Operation
This chapter provides an introduction to MT3334HD8 command mode fundamentals, followed by a
detailed explanation of each AT command, providing examples where applicable.
Chapter 4 S-Registers
This chapter describes the MT3334HD8’s S-registers, which are used to store various modem options.
Each S-register is defined and explained.
Chapter 5 Testing the MT3334HD8
This chapter describes loopback testing for the MT3334HD8.
Chapter 6 Warranty, Service, and Technical Support
This chapter provides the terms of the MT3334HD8’s warranty, instructions for obtaining factory service,
and information about Multi-Tech’s BBS and technical support. Information on upgrading the
MT3334HD8’s firmware is also provided.
Appendix A ASCII Conversion Chart
Appendix B Dial Pulses and Tones
Appendix C Result Code Summary
Appendix D S-Register Summary
Appendix E AT Command Summary
Appendix F Remote Configuration
CommPlete Communications Server 3
MT3334HD8 User Guide
j
g
Technical Specifications
Model Number MT3334HD8
Data Rates (Modem) Eight independent modems (Modem A, B, C, D, E, F, G, H), each operating at
33,600, 31,200, 28,800, 26,400, 24,000, 21,600, 19,200, 16,800, 14,400, 12,000,
9600, 4800, 2400, 1200, or 0-300 bps
Data Rates (Fax) 14,400, 9600, 4800, and 2400 bps
Data Format
(Modem)
Configuration Each of the card’s modems is independently configurable
Compatibility (Modem) ITU-T V.42bis, V.42, V.34plus, V.34, ITU-T V.32bis, V.32, V.25bis, V.21,
Compatibility (Fax) ITU-T Group 3, T.4, T.30, V.21, V.27ter, V.29, V.17, and EIA TR29.2
Error Correction ITU-T V.42 (MNP® Classes 3 and 4, and LAP-M)
Data Compression ITU-T V.42bis (4:1 throughput) or MNP 5 (2:1 throughput)
Speed Conversion Serial port data rates ad
Flow Control XON/XOFF, CTS/RTS, ENQ/ACK
Mode of Operation Half or full duplex over dial-up lines; automatic or manual dialin
Intelligent Features Fully AT command compatible; auto dial; redial; repeat dial*; dial linking*;
AT Commands 100% compatible with standard AT command set
Serial, binary, asynchronous at all data rates
V.22bis, V.22, V.23, V.17, Bell 212A* and 103/113*
ustable to 300, 1200, 2400, 4800,9600, 19,200, 38,400,
57,600, and 115,200 bps
, automatic
or manual answer
pulse or tone dial; dial pauses; call status display; auto-parity and data rate
selection; keyboard-controlled modem options; nonvolatile memory; onscreen displays of modem parameters, stored telephone numbers, and help
menus; and remote configuration.
Command Buffer 60 characters
Automatic Dialing Standard AT command asynchronous dialing
Modem Modulations FSK at 300 bps, PSK at 1200 bps, QAM at 2400, 4800, and 9600 bps (non-
trellis), QAM with trellis-coded modulation (TCM) at 9600, 12,000, 14,400,
16,800, 19,200, 21,600, 24,000, 26,400, 28,800, 31,200, and 33,600 bps
Fax Modulations V.21 CH2 FSK at 300 bps
V.27ter DPSK at 4800 and 2400 bps
V.29 QAM at 9600 and 7200 bps
V.17TCM at 14400, 12000, 9600, and 7200 bps
Carrier Frequencies
ITU-T V.34
Carrier Frequencies:
V.22bis/V.22 or
Bell 212A Standard
4 CommPlete Communications Server
1600, 1646, 1680, 1800, 1829, 1867, 1920, 1959, 2000 Hz
Transmit originate:
Transmit answer:
Receive originate:
1200 Hz
2400 Hz
2400 Hz
(2400 & 1200 bps) Receive answer: 1200 Hz
1 Introduction
Carrier Frequencies:
Bell 103/113
(300 bps)
Carrier Frequencies:
V.21
Carrier Frequencies:
V.23
Transmit originate:
Receive originate:
Transmit answer:
Receive answer:
Transmit originate:
Receive originate:
Transmit answer:
Receive answer:
Transmit originate:
Receive originate:
Transmit answer:
Receive answer:
1270 Hz mark
1070 Hz space
2225 Hz mark
2025 Hz space
2225 Hz mark
2025 Hz space
1270 Hz mark
1070 Hz space
980 Hz mark
1180 Hz space
1650 Hz mark
1850 Hz space
1650 Hz mark
1850 Hz space
980 Hz mark
1180 Hz space
390 Hz mark
450 Hz space
1300 Hz mark
2100 Hz space
1300 Hz mark
2100 Hz space
390 Hz mark
450 Hz space
Fax Modulations V.21Ch2 FSK at 300 bps
V.27ter DPSK at 4800 and 2400 bps
V.29 QAM at 9600 and 7200 bps
V.17 TCM at 14400, 12000, 9600, and 7200 bps
Fax Carrier
Frequencies
V.21 CH2 (half duplex)
1650 Hz mark, 1850 Hz space for transmit originate
1650 Hz mark, 1850 Hz space for transmit answer
V.27ter: 1800 Hz Originate/Answer
V.29 QAM: 1700 Hz Originate/Answer
V.17 TCM: 1800 Hz Originate/Answer
Transmit Level -13 dBm
Frequency Stability +0.01%
Receiver Sensitivity -43 dBm under worst case conditions
AGC Dynamic Range 43 dB
Serial Interface EIA RS-232C
Diagnostics Power-on self-test; ITU-T V.54 local analog loop, local digital loop, remote
digital loop.
Firmware Upgrades Flash memory; available on Multi-Tech’s BBS
Indicators LEDs for Carrier Detect and Off Hook/Out-Of-Service
Environmental Temperature range: 0°–50°
C (32°–120° F)
Humidity range: 20–90% (noncondensing)
CommPlete Communications Server 5
MT3334HD8 User Guide
Power
Requirements
5 VDC at 0.95 A
±16 VDC at 0.1 A
Power Consumption Approximately 6 watts
Dimensions 23.3 × 2.3 × 29.2 cm (9.2 × 0.9 × 11.5 in.) H × W × D
Weight 1.1Kg (2.5 lb.)
Limited Warranty Two years
Fuses F1 (+5 V), F2 (-16 V), F3 (+16 V)
6 CommPlete Communications Server
2 Installation
CommPlete Communications Server 7
MT3334HD8 User Guide
Introduction
This chapter describes how to install the MT3334HD8 modem card into a CommPlete Communication
Server CC9600 chassis. This equipment should be installed only by a qualified service person.
The MT3334HD8 assembly consists of a high-density modem card and a front panel. Figure 1 shows the
layout of the MT3334HD8 card. The MT3334HD8 assembly plugs into power and data, Ethernet, and T1
bus connectors on the inside of the CC9600 chassis. There are no external connectors.
LEDs
Connectors
Figure 1. MT3334HD8 modem card.
Safety Warnings
✔ Never install telephone wiring during a lightning storm.
✔ Never install telephone jacks in wet locations unless the jacks are specifically designed for wet
locations.
✔ Never touch uninsulated telephone wires or terminals unless the telephone line has been disconnected
at the network interface.
✔ Use caution when installing or modifying telephone lines.
✔ Avoid using a telephone (other than a cordless type) during an electrical storm. There may be a remote
risk of electrical shock from lightning.
✔ Do not use the telephone to report a gas leak in the vicinity of the leak
✔ Ports that are connected to other apparatus are defined as SELV. To ensure conformity to EN 41003,
ensure that these ports are only connected to the same type on the other apparatus.
8 CommPlete Communications Server
Pre-Installation Notes
Warning: Interconnection directly, or by way of other apparatus, of ports marked “SAFETY WARNING
see instructions for use” with ports marked or not so marked may produce hazardous conditions on the
network. Advice should be obtained from a competent engineer before such a connection is made.
• All installation must be done by a qualified service person.
• To reduce emissions, be sure to use blanking plates to cover empty slots in the CC9600 chassis.
• Any other apparatus, including cable and wiring, connected between the MT3334HD8K modem and
the point of connection to any speech band circuit shall comply with the following:
1. The overall characteristics of this apparatus shall be such as to introduce no material effect upon
the electrical conditions presented to one another by the modem and he speech band circuit.
2. The apparatus shall comprise only
a. apparatus approved for the purpose of connection between the modem and a speech band
circuit; and
b. cable and wiring complying with a code of practice for the installation of equipment
covered by this part of BS 6328 or such other requirements as may be applicable.
2 Installation
Note: Such apparatus may have been approved subject to limitations in its use.
Installation Procedure
1. Unpack the MT3334HD8 assembly from its packaging and save the packaging for possible future
use. Perform a visual inspection of the MT3334HD8. If you are concerned about its condition, call
Technical Support for instructions.
2. Turn off
3. The MT3334HD8 must be installed in a segment in which a RASCard with a T1 module is installed.
Remove a blank device panel or previous MT3334HD8 card from that segment.
4. Supporting the MT3334HD8 by the front panel and the bottom edge of the card, place it into the
CC9600’s open device slot. Make sure the edges of the MT3334HD8 card mate properly with the
guides of the device slot.
5. Slide the MT3334HD8 into the CC9600 chassis until you feel the MT3334HD8’s connectors mate with
the CC9600’s bus connectors.
6. Tighten the MT3334HD8’s retaining screws.
7. Turn on the PS9600 power supplies.
8. Note the PS9600 LED indicators. If they are not lit, see Chapter 5. If they are lit, proceed with
MultiModemManager operation (Chapter 4 of the MultiModemManager
both
PS9600 power supplies.
Owner’s Manual
).
Note: A self-test runs each time the CommPlete Communications Server is turned on. Refer to Chapter 5
of the MultiModemManager Owner’s manual for more details on the power-on self-test.
CommPlete Communications Server 9
3 AT Commands
CommPlete Communications Server 11
MT3334HD8 User Guide
Working with AT Commands
The MT3334HD8’s modems are controlled by instructions called
attention characters
send commands to the modem from your keyboard while in terminal mode, or you can use communications software to issue these commands automatically.
A MT3334HD8 modem is in command mode when it is not dialing or online. When it is in command
mode, you have access to a complete communications system that allows you to use several features,
including the basic AT command set described in this chapter. Using the basic AT command set, you can
enter phone numbers for automatic dialing, configure modem options, and monitor telephone activity. In
addition, you can command your modem to perform advanced features such as error correction, data
compression, speed conversion, and more.
This chapter describes the MT3334HD8’s operational modes, and shows you how to use each of the
MT3334HD8’s AT commands. MT3334HD8 commands and responses are compatible with all systems and
with all data communications software using the AT command set.
For easy reference, the MT3334HD8 has a help command that provides you with short, on-screen
descriptions of the modem commands. The help command is explained later in this chapter.
Modes of Operation
The MT3334HD8 operates in two basic functional modes:
an in-between state,
When you power up the modem, it is in command mode, and is ready to accept and respond to commands
from your keyboard or software.
AT commands
AT
precede each command or command string (sequence of commands). You can
command mode
wait-for-carrier
, in which the modem is out of command mode but not yet online.)
, so called because the
and
online mode
. (There is also
An MT3334HD8 modem enters online mode after it dials, connects with another modem, and detects a
valid carrier signal. If it does not detect a carrier signal within the time frame controlled by register S7, the
modem abandons the call and re-enters command mode.
You can make the modem enter online mode without dialing by typing either the D command or the A
command.
The modem exits online mode if the carrier signal is lost or intentionally dropped. When this happens, the
modem hangs up and re-enters command mode.
By sending certain “escape” characters to the modem while online, you can make it enter command mode
without losing the carrier signal.
For auto answer-only applications, you can disable a modem’s ability to recognize AT commands by using
the %DC1 command. When you do this, the MT3334HD8 ignores all commands, and functions as a nonintelligent modem. The %DC1 command and other MT3334HD8 commands are explained later in this
chapter.
Command Structure
You can control a wide variety of modem operations and options when the modem is in command mode.
AT commands tell the modem to dial a number, to answer a call, to operate at a certain speed, to use a
certain compression technique, and many other functions. AT commands consist of one or two letters,
which may be preceded by an ampersand (
character (
modem returns result codes, while the &Q command selects which AT command set the modem uses.
&
), a dollar character ($), a pound character (#), a percent
%
), or a greater-than character (>). The Q command, for example, determines whether the
12 CommPlete Communications Server
A parameter after a command (0, 1, 2, etc.) tells the modem which option to use. If you do not specify a
parameter, the modem assumes the 0 (zero) option. E, for example, is the same as E0. You can issue
several commands on a single line (a command string) as long as the line does not exceed 60 characters.
Note that though Q1 is one command, it counts as two characters in the command line.
Each command has a valid range of parameters; for instance, &W can have only 0 or 1 as a parameter.
Valid commands generate an
parameters. An invalid command, such as &W3, which has a parameter outside the valid range, generates
ERROR
an
turned on or reset with the ATZ or AT&F command. Factory defaults are stored in read-only memory
(ROM), and cannot be changed. User-defined defaults can be stored in nonvolatile random-access
memory (NVRAM), and can be changed or deleted at will.
Command Editing
Always begin a command with the letters AT. You may type the command in upper case or lower case, but
not both. The AT command is not executed until you press the E
the previous command character; it will not erase the AT characters once they are typed. If your keyboard
has no B
to any other ASCII character by changing register S5.
3 AT Commands
OK result code. A few generate an additional response, such as a list of
result code. Most commands have a default parameter, one that is enabled when the modem is
NTER key. Use the BACKSPACE key to erase
ACKSPACE key, use CTRL+H. You can change the character recognized by the modem as BACKSPACE
To cancel an entire command that has been typed but not yet executed, press C
TRL+X. This also clears the
command buffer. The effect is the same as backspacing the command, only quicker.
The MT3334HD8 stores characters entered in a command in the modem’s command buffer until they are
executed by pressing E
NTER. The command buffer’s capacity is 60 characters. The attention characters
(AT) do not count in the 60 allowed command characters. You may use spaces for increased readability
when typing a command; they are neither stored in the command buffer nor counted in the 60 allowed
characters. Hyphens, parentheses, etc., are not allowed.
If you exceed the 60-character limit or type invalid characters, the command buffer is automatically erased
ERROR
and an
message is displayed. You must then retype the command within the 60-character limit,
using only the allowed characters.
The commands in this chapter are organized by function. A brief summary follows.
CommPlete Communications Server 13
MT3334HD8 User Guide
Table 1. AT Commands by Function
Topic Command Description Page
Dialing Action D Dial 16
Dial Modifiers P Pulse dialing 16
Phone Number D...N Store a phone number 19
Memory N Dial a stored number
A: Continuous redial
H On-hook/off-hook
T Tone dialing
W W ait for new dial tone
R Reverse originate/answer mode
, Dialing pause
: Continuous redial
; Return to command mode after dialing
! Flash on-hook
@ Quiet answer
$ Call card tone detect
N...N Number linking
L List stored telephone numbers
Configuration &W Store configuration 20
Storage & Recall &F Load default configuration
Z Reset modem
Modem Responses E Echo command mode characters 21
(Result Codes) Q Result codes: enable/disable
&Q Result codes: Multi-Tech or standard
V Result codes: verbose/terse
X Result codes and call progress
&A Answerback
Online Connection #A Auto speed detection 24
B Answer tone
%DC Command mode control
&CD Cleardown at disconnect
>DT DTMF detection
#F Fallback modes when online
&G Guard tones
*H Busy-Out After Disconnect
&P Pulse dial ratios
&RD Square wave ring detect
$T Calling tones
#T Trellis-coded modulation
Y Long space disconnect
V.34 Controls %F Echo canceler frequency offset comp. 28
&RA Asymmetric bit rate
RS-232 Interface &C Carrier Detect control 29
Controls &D Data Terminal Ready control
&R Clear to Send control
&S Data Set Ready control
&RF CTS/RTS interaction control
&SF DSR/CD interaction control
14 CommPlete Communications Server
3 AT Commands
Error Correction & &E0 Non-error correction mode 31
Data Compression &E1 Auto-reliable mode
&E2 Reliable mode
&E14 Data compression disabled
&E15 Data compression enabled
#L V.42 error correction modes
$E V.42 error correction at 300 bps
$A Auto-reliable buffering
$F Auto-reliable fallback character enable
$R Retransmit count
Speed Controls $BA Baud adjust 33
$MB Modem baud rate
$SB Serial port baud rate
Immediate Action A/ Repeat last command 35
I Inquire product code
L5 List current operating parameters
L6 List S-register values
L7 List current operating parameters
L8 List online diagnostics
&RN Rate renegotiation
&RR Retrain
Flow Control &BS Maximum reliable block size 36
$EB Asynchronous word length (10/11-bit)
&E3 Flow control disabled
&E4 Hardware flow control
&E5 XON/XOFF flow control
&E6 XON/XOFF no pass-through
&E7 XON/XOFF pass-through
&E8 Hewlett Packard ENQ/ACK pacing off
&E9 Hewlett Packard ENQ/ACK pacing on
&E10 Non-error correction mode flow control off
&E11 Non-error correction mode flow control on
&E12 Pacing off
&E13 Pacing on
#X Number of XOFF characters sent
Escape +++AT<CR> Default in-band escape sequence 39
Sequences <BREAK>AT<CR> Alternate out-of-band escape sequence
%E Escape sequence selection
A Force answer mode
O Go back online
Remote %%%AT<CR> Remote configuration escape sequence 40
Configuration #I Change login password
#S Change setup password
Line Probes %DP Read line probe data 41
%DF Format line probe data
&RP Immediate line probe
L9 Display signal strength
L10 Display signal to noise ratio
L11 Display noise strength
Diagnostics &T Respond to remote digital loopback signal 42
U Loopback test modes
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MT3334HD8 User Guide
Dialing Commands
Dialing commands are used to dial and to hang up.
Ds Dial
s
= phone number
Default: none
D
The letter
example, if you type ATD5551212<CR>, the modem dials the number 555-1212.
The MT3334HD8 supports several dialing methods. With the D command, you can specify either pulse
(ATDP) or tone (ATDT) dialing. You can also modify the dialing command with several characters that
are explained in “Dial Modifier Commands” in this chapter.
The MT3334HD8 lets you select either smart (wait-for-dial-tone) dialing or blind dialing. With smart
dialing, the modem waits for and detects dial tones and busy signals. With blind dialing, the modem works
with timed pauses (determined by the value of register S6), not dial tone and busy signal detection. See the
X command for more information on blind and smart dialing.
A: Continuous Redial
in a command causes the modem to dial the telephone number immediately following it. For
If you select smart dialing through the X3 or X4 command, the A: command lets you continuously redial a
busy number until your call is answered. (North American units have a maximum of 10 redials; this
command is not available on UK or International models.)
Use this command only if you have reached a busy number after executing a normal dial command. Type
AT
A: (you need not type
again reach a busy signal, the modem continues to redial until it gets through. You can stop the modem
from redialing by pressing any key.
To save a step when redialing a phone number, enter a colon (:) at the end of the phone number. The result
is the same as if you had entered A:
, nor do you need to press ENTER), and the modem redials the number. If you
Hn On-Hook/Off-Hook
n
= 0 or 1
Default: none
You can make the modem go on-hook (hang up) or go off-hook with the H command.
H0 (or H) hangs up the modem
H1 brings the line off-hook, just as if you had picked up the telephone handset.
It is not necessary to use the H1 command to bring the line off-hook when using the D command. The
modem automatically goes off-hook when you press E
Dial Modifier Commands
NTER at the end of the dial command.
The dial string can include the digits 0 through 9, the pound sign (#), the asterisk (*), and the letters A, B,
C
, or D. The latter are used by some PBXs; the exact function will depend on the PBX manufacturer’s
feature set and implementation. There are also several command characters, called “dial modifiers,” that
D
can be included within a dialing command after the letter
16 CommPlete Communications Server
. Their functions include pulse or tone dialing,
pauses in the dial sequence, automatic redials if a number is busy, and reverting to command mode or
switching to answer mode after dialing.
P, T Pulse or Tone Dialing
Default: P
The MT3334HD8’s modems can dial numbers by using pulse dialing, tone dialing, or a combination of
both methods. Pulse dialing, used by rotary-dial telephones, uses the timed opening and closing of a relay
to encode the numbers. Tone dialing, used by push-button (touch-tone) telephones, uses dual tone
multifrequency (DTMF) dialing.
P selects pulse dialing.
T selects tone dialing.
Insert P or T in the dialing command just before the digits you want to pulse- or tone-dial.
3 AT Commands
For example, to pulse-dial the number 555-1212, type ATDP5551212 and press E
same number, type ATDT5551212 and press E
dial command, the modem uses whatever method was used last.
Immediately after the modem has been turned on or reset, it uses pulse dialing, even if you do not include
P in your dial command.
As an example of combining pulse and tone dialing, assume you are calling out of a PBX (switchboard)
9
system where a
has to be pulse-dialed, then the rest of the number has to be tone-dialed after pausing for
a second dial tone. To dial this example, type ATDP9,T5551212 and press E
pause.)
W Wait for New Dial Tone
Inserting W into the dialing command causes the modem to wait for another dial tone before it resumes
dialing. (It is not necessary to enter W at the beginning of the dialing command.)
Because the modem must be able to detect the dial tone for this command to work, you also
must select wait-for-dial-tone dialing with the X2 or X4 command.
NTER. To tone-dial the
NTER. If neither pulse nor tone dialing is specified in the
NTER. (The comma causes a
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MT3334HD8 User Guide
Rn Reverse Originate/Answer Mode
n
= 0 or 1
Default: R0
The R command lets you reverse the modem’s mode of operation from originate to answer, or from
answer to originate; for example, if you need the modem to answer the phone but then go into originate
mode.
R (with no number) at the end of the dialing string reverses in originate mode.
R0 disables mode reversing.
R1 enables mode reversing when R is added to the dial string.
, Dialing Pause
Enter a comma in the dialing string to make the modem pause while dialing. This pause lasts two seconds
(North American models) or four seconds (U.K. and International models) for each comma entered. You
can force longer pauses by entering multiple commas, or you can change the length of the pause caused by
a comma by setting register S8 to any value from 0 through 255 seconds (North American models), 4 through
7 seconds (U.K. models) or 4 through 255 seconds (International models).
Each comma in a dialing command counts as one of the 60 allowed characters.
: Continuous Redial
Enter a colon (:) as the last character of a dialing command to cause the modem to continuously redial the
number, if it detects a busy signal, until the call is answered. North American models are limited to 10
redials. You must select smart dialing (X3 or X4) for this to work. (Not available in U.K. or International
models.)
Note: This command has largely been superseded by software-based continuous redial features.
; Return to Command Mode After Dialing
Enter a semicolon (;) as the last character of a dialing command to cause the modem to return to
command mode immediately after executing the command instead of waiting for a carrier signal and
going online.
For example, type ATDT5551212; to tone-dial the number and immediately go back into command mode.
The semicolon is useful when modem data transfer is not desired, as in voice communications, or in
applications using touch tones as a data entry method, such as bank-by-phone.
! Flash On-Hook
Some switchboard systems react to a momentary on-hook condition. Insert an exclamation mark into the
dialing command to cause the modem to “flash” on-hook for half a second, just as if you had pressed the
switch hook on a telephone set for half a second. (With U.K. models, the exclamation mark causes the
modem to flash on-hook for 90 milliseconds.)
For example, to flash on-hook to transfer to extension 5678 after dialing the number 555-1234, type
ATDT5551234,,!5678. The commas cause a 4-second pause.
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@ Quiet Answer
Use the @ command to access a system that does not provide a dial tone. The @ command causes the
modem to wait before processing the next character in the dialing string. The wait is for one or more rings
back followed by five seconds of silence.
For example, ATDT5551212@6313550 causes the modem to dial the first number (555-1212), then wait
for the time specified in register S7
detects a busy signal, it hangs up and generates a
silence, it hangs up and generates a
dials the second number (631-3550).
$ Call Card Tone Detect
3 AT Commands
for at least one ringback and five seconds of silence. If the modem
BUSY
result code. If it does not detect five seconds of
NO ANSWER result code. If it does detect five seconds of silence, it
Use the $ command to dial services that require you to enter your call card number after a tone. A
character in the dialing string causes the modem to pause and wait for an AT&T call card “bong” or a 1600
Hz tone (prevalent in the U.K.). When the modem detects the tone, it processes the rest of the dialing
string. If it does not detect a tone within the time set by register S7 (a 45-second default), the modem
aborts with a
In the following example, the $ command is placed between an access/phone number and the caller’s
credit card number:
ATDT1028806127853500$123456789
NO CARRIER message. Pressing any key also aborts the $ command.
Phone Number Memory Commands
The modem can store up to two telephone numbers in nonvolatile memory. You can store the numbers
with the DsNd command, dial them with the Nd command, link them so that one will be automatically
dialed after the other with the NdNe command, or list them with the L command.
DsNd Store a Phone Number
s
= phone number d = 0 or 1
Default: none
You can store a telephone number command string of up to 60 characters in the modem’s phone number
memory. You can store two of these 60-character strings using the DsNd command. The memory
N0
locations are labeled
and N1.
$
Store a command line by typing it as you would any other command, appending the appropriate Nd
memory location.
For example, the tone-dialed number 1-612-555-1212 is stored at memory location N0 by typing
ATDT16125551212N0 and pressing E
After storing a number, check to see that it has been stored correctly by typing ATL and pressing Enter.
When you store a phone number, you store the entire command string, so you can effectively create a
macro for each number. For example, if you know a particular number needs to have extended result
codes, detect busy or dial tone, error correction, XON/XOFF flow control, pacing, and data compression enabl ed, the
command to store the entire command string at location N0 is ATX4&E1&E5&E13&E15DT16125551212N0.
NTER. The number is not dialed with this store command.
Nd Dial a Stored Number
d
= 0 or 1
Default: none
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MT3334HD8 User Guide
You can automatically dial a telephone number that is stored in the modem’s number memory by typing
ATN
mode and pressing E
Warning: Do not include the letter
NdNe Number Linking
d
= 0 or 1 e = 1 or 0
Default: none
Number linking allows the modem to dial a second stored number if the first stored number is busy. (See
the DsNd command.) This command is useful when a computer can be accessed through more than one
phone number. However, it cannot be used with blind dialing, since busy signals would not be detected.
To link the number in memory location N0 to the number in N1, type ATN0N1 and press Enter. You can
cycle back and forth between two numbers by linking them several times in one command:
ATN0N1N0N1N0N1<CR>. The only limit on the number of times the modem can cycle between two
numbers is the 60-character maximum allowed in a command line.
L List Stored Telephone Numbers
Use the L command to display dialing commands stored in the modem’s nonvolatile memory. Typing
ATL<CR> displays the stored N numbers in the following format:
n
, where n = 0 or 1. For example, you can dial a number stored at N0 by typing ATN0 in terminal
NTER.
D
in this command, or the stored number will be erased.
0 T14082345678
1 P9,T14089876543
All digits and command letters are displayed. The N number is shown first, followed by the complete
dialing command and telephone number as originally entered.
Configuration Storage and Recall Commands
The MT3334HD8 stores parameters in two places. It stores factory default parameters in read-only
memory (ROM), and customized parameters in nonvolatile random access memory (NVRAM). You cannot change the default parameters in ROM; however, you can change parameters in temporary memory
and then store them in NVRAM as custom settings. You can then recall the custom settings as if they were
factory default settings.
&Wn Store Configuration
n
= 0 or 1
Default: &W1
The &W command stores current AT commands and S-register values in nonvolatile memory, so you
won’t lose your custom settings when you turn off the modem or reset it.
&W0 (or &W) stores all current AT command and S-register values in nonvolatile random access memory
(NVRAM) and configures the modem so that it reads your custom settings in NVRAM when the modem is
turned on or when it is reset with the Z command. (The &F reset command will continue to read the
factory default settings in ROM unless you store the &F9 command.)
&W1 erases your custom settings in NVRAM when the modem is turned off or reset, causing the modem to
read the factory default settings in ROM when it is subsequently turned on or reset.
For further information on how the &W command interacts with the reset commands, see Table 2.
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&Fn Load Default Configuration
n
= 0, 8, or 9
Default: &F8
MT3334HD8 modems store factory default AT command settings and S-register values in read-only
memory (ROM); they store your custom AT command and S-register values in nonvolatile random access
memory (NVRAM).
The &F0 (or &F) command resets the modem to the factory default values stored in ROM or to your
custom values stored in NVRAM, depending on whether you last stored an &F8 or an &F9 command.
When &F8 is stored and an &F command is issued, the modem reads the factory default settings stored in
ROM.
When &F9 is stored and an &F command is issued, the &W setting determines whether the modem reads
settings stored in NVRAM or ROM. If the modem is set to &W0, it reads your custom settings stored in
NVRAM. If the modem is set to &W1, it erases your stored settings (including the &F9 command) and
reads the factory default settings stored in ROM. Many communications programs issue the &F command
automatically—the &F9 command allows you to select your own defaults.
Note that for either an &F8 or an &F9 command to be effective after a reset it must be stored using the
&W0 command.
Table 2 summarizes how the &F and Z reset commands interact with the &W command; note that the &F
reset command operates differently from the Z reset command:
3 AT Commands
Table 2. Where the Modem Reads Configuration Parameters
Previous Command AT&F Power-On and ATZ
AT&W1 (default) ROM ROM
AT&W0 ROM NVRAM
AT&F8&W0 ROM NVRAM
AT&F9&W0 NVRAM NVRAM
Z Reset Modem
The Z command resets the modem to its default configuration and clears the command buffer. The result
is the same as turning the modem off and on. When you type ATZ, the state of the &W command
determines where the default values originate. &W0 defaults come from the customized configuration in
NVRAM, and &W1 defaults come from the factory default configuration in ROM. Because Z clears the
command buffer, it must be the last command in a command string; normally it is issued by itself: ATZ.
Note that the Z reset command operates differently from the &F reset command. See Table 2 on page 21.
Modem Response (Result Code) Commands
The MT3334HD8’s modems can give responses to commands. The most common one is OK, but the
modems also can alert you or your software to dial tones, busy signals, connection speeds, and whether the
connection is made with error correction or compression enabled. These responses are called
and they can be terse or verbose, Multi-Tech or standard, basic or extended.
result codes
,
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MT3334HD8 User Guide
En Echo Command Mode Characters
n
= 0 or 1
Default: E1
Normally, when you type commands on the keyboard, the modem echoes the characters back to the
computer or terminal, which displays them on the monitor. Use the E command to turn this feature off
and on.
E0 disables the echo.
E1 enables the echo.
Qn Result Codes Enable/Disable
n
= 0, 1, or 2
Default: Q0
You can use the Q command to enable or disable result codes for applications such as computer-controlled
auto dialing. You can also use it to disable responses and echo in answer mode while leaving originate
mode still intelligent; this is called the no response answer mode of operation.
Q0 (or Q) enables result codes.
Q1 disables result codes for applications such as computer-controlled auto-dialing.
Q2 enables the no response answer mode, which leaves originate mode intelligent while turning off answer
mode responses and echo.
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&Qn Result Codes (Multi-Tech or Standard AT)
n
= 0 or 1
Default: &Q0
The MT3334HD8 gives you a choice between Multi-Tech result codes and standard AT command set
responses. Multi-Tech result codes give you more information, but some datacomm programs may not be
able to use them, in which case, select the standard result codes.
3 AT Commands
&Q0 selects Multi-Tech responses with
the verbose result code for 14,400 bps is
&Q1 selects AT responses with no
verbose result code for 14,400 bps is
RELIABLE, LAPM, and COMPRESSED
CONNECT 14400 LAPM COMPRESSED.
RELIABLE, LAPM, or COMPRESSED
CONNECT 14400.
Vn Result Codes (Verbose/Terse)
n
= 0 or 1
Default: V1
The V command controls whether the modem’s result codes display as verbal (“verbose”) or digital
(“terse”) messages. For example, if no carrier signal is detected after dialing, the result can be displayed
either as
V0 (or V) displays the modem’s result codes as digits.
V1 displays result codes as words.
NO CARRIER, or as the digit 3.
Xn Result Codes and Call Progress Selection
n
= 0–4
Default: X0
The X command selects which result codes the modem provides in command mode and whether the
modem uses “smart dialing” or “blind dialing”. When it smart dials, the modem listens for dial tones and
busy signals and responds to them. When it blind dials, the modem ignores the signals and relies on
timing instead.
modifiers. With &Q0,
modifiers. With &Q1, the
X0 causes the modem to blind dial. Instead of looking for a dial tone, it pauses for the time set in register
S6 and then dials regardless. Once a connection has been made, it sends the Bell 103 basic code
CONNECT
X1 causes the modem to blind dial, but in addition to the basic
codes consisting of the word
CONNECT 4800, CONNECT 9600, CONNECT 14400, CONNECT 19200, CONNECT
28800
signals.
X2 causes the modem to wait for a dial tone before dialing. If it does not detect a dial tone within the time
set by S6, the modem sends a
vides extended result codes, but does not respond to busy signals.
X3 causes the modem to blind dial, but also it looks for a busy signal, and if it detects one, it sends a BUSY
result code to the terminal. In this mode, the modem provides extended result codes, but it does not
respond to dial tones.
X4 causes the modem to look for a dial tone and a busy signal, and respond with NO DIALTONE or
BUSY, as appropriate. It also provides extended result codes. It is the most useful setting for most
datacomm programs.
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to the terminal. It ignores any busy signals.
CONNECT
CONNECT
,
and so forth. In this mode, the modem does not recognize or respond to dial tones or busy
NO DIALTONE result code to the terminal. In this mode, the modem pro-
and the speed of the connection: CONNECT 2400
code it provides extended
,
MT3334HD8 User Guide
&An Answerback
n
= 0 or 1
Default: &A0
The &A command controls the MT3334HD8’s answerback feature. Answerbacks are used in some online
realty applications and elsewhere as a security measure. The &A command enables a modem to return a
message to an identification request from another computer. The default identification is
NOT PROGRAMMED
&A0 disables the answerback feature.
&A1 enables the modem to return a message to an inquiry.
.
Online Connection Commands
The following commands control the conditions of the online connection.
#An Auto Speed Detection
n
= 0–3
Default: #A0
MESSAGE
An MT3334HD8 modem can operate as a 33,600 bps, 28,800 bps, 19,200 bps, 14,400 bps, 9600 bps, 4800
bps, 2400 bps, or 300 bps modem. Use the #A command to select the speed that the modem uses for initial
handshaking and subsequent speed selection. The #A command does not control the originating rate of the
modem (that is done by the modem baud rate command $MB), but only the answer mode starting speed.
#A0 causes the modem to start at maximum speed, with fallback to 31,200 to 28,800 to 26,400 to 24,000 to
21,600 to 19,200 to 16,800 to 14,400 to 12,000 to 9600 to 4800 to 2400 to 1200 to 300 bps.
#A1 causes the modem to operate at maximum speed only.
#A2 causes the modem to start at maximum speed, with decremental fallback to 4800 bps.
#A3 causes the modem to start at 2400 bps in V.22bis mode, with fallback to 1200 to 300 bps.
Bn Answer Tone
n
= 0 or 1
Default: B0
The B command selects the frequency the modem uses for its answer tone. (The answer tone is the tone a
modem receiving a call transmits to the modem that called it, thus initiating the handshake between the
two modems.) At higher speeds (2400 to 33,600 bps) there is no conflict, because all protocols use the Bell
frequency of 2225 Hz. However, the ITU-T specification for V.22 has an answer tone frequency of 2100 Hz.
This command is available only in International models.
B0 enables ITU-T frequencies including V.21 (300 bps) and V.23 (1200/75 bps).
B1 enables Bell frequencies including Bell 103 (300 bps).
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