Octek SMART MoDeM, VoiceMaster, Socket Rocket Reference Guide
SmartModem
Reference
Guide
SmartModem
VoiceMaster
Socket Rocket
Revision C
January, 1996
YML212-3
NetComm Code Version V2.65
ISBN 0 947206 95 7
Copyright
This manual is copyright. Apart from any fair dealing for the
purposes of private study, research, criticism or review, as
permitted under the Copyright Act, no part may be reproduced,
stored in a retrieval system or transmitted in any form, by any
means, be it electronic, mechanical, recording or otherwise,
without the prior written permission of NetComm Limited.
Disclaimer
NetComm Limited accepst no liability or responsibility, for
consequences arising from the use of this product.
NetComm Limited reserves the right to change the specifications and
operating details of this product without notice.
Trademarks
NetComm, ProRack, Faxnet, CellModem and Cooee are
registered trademarks of NetComm Limited
SmartModem, AutoModem, PocketModem, Smart/Rack, PC Fax Card,
FastFix, TNP, and AutoSoft are trademarks of NetComm Limited
MNP is a registered trademark of Microcom Inc
Microcom Networking Protocol is a trademark of Microcom Inc
Hayes is a registered trademark of Hayes Microcomputer
Products Inc
IBM is a registered trademark of International Business
Machines Corporation
MS-DOS is a registered trademark of Microsoft Inc
WordStar is a registered trademark of Micropro International
Corporation
WordPerfect is a registered trademark of WordPerfect
Corporation
©1995 NetComm Limited ACN:002490486
PO Box 379 North Ryde NSW 2113 Australia
Incorporated in New South Wales Australia
SmartModem Reference Guide
i
NetComm Limited
SOFTWARE PROGRAM LICENSE
1. NetComm grants its Customers a non-exclusive license (the “License”) to use any
software programs (the “Programs”) used in connection with the Products and supplied
by NetComm.
2. The Customer assumes responsibility for the selection of the Programs to achieve its
intended results and for the installation, use and results obtained from the Programs.
3. The Customer may:
(a) use the Programs on a single machine;
(b) copy the Programs into any machine readable or printed form for backup
purposes in support of use of the Programs on a single machine (certain
Programs may, however, include mechanisms to limit or inhibit copying); and
(c) transfer the License to a purchaser of the relevant Products and the Customer
shall at the same time either deliver all copies of the Programs, whether in
printed or machine-readable form, to the purchaser or destroy any copies not
so delivered.
4. The Customer shall bring to the attention of any transferee of the License these terms
upon which the License is granted.
5. If for any reason the License is terminated, the Customer shall procure the destruction
of all Programs (including all copies of them).
6. NetComm warrants that the Programs will carry out the functions described in the
Product Manual but does not warrant that the Programs or any particular copies of
them will be free from particular defects. If the Programs are found to be defective,
NetComm will replace the Programs provided the medium on which the Programs
reside is returned (shipping prepaid and properly packed) to NetComm. Proof of
the Customer’s license to the satisfaction of NetComm must accompany any request
for warranty.
7. Improved or modified versions of the Programs may be made available under license
to the Customer, at NetComm’s absolute discretion and upon payment of its then
current Charges. NetComm may require the return or destruction of previous versions
of the Programs and evidence of the License to use those Programs. New versions
shall be licensed to the Customer upon the same terms and conditions as are contained
in this Clause 7 and the License to use prior versions of the Program shall terminate
upon delivery to it of the new versions of them.
ii
SmartModem Reference Guide
HARDWARE WARRANTY
1. NetComm grants a warranty in relation to the Products for the period set
out in the relevant Product Manual, from the original date of purchase, on
the following conditions:
(a) this warranty covers component failure, defective materials and
production defects only;
(b) warranty if it complies with all of the terms of the Agreement and any
other reasonable requirements of NetComm including producing such
evidence of purchase as NetComm may require;
(c) the Customer may not rely on this warranty if any cost, loss or damage
to the Products or otherwise arises as a result of or in connection with
the negligence or default (including but not limited to any failure to
comply with the Product Manual or NetComm’s training) of the
Customer;
(d) the Customer shall be solely responsible for delivery of the Products to
and from NetComm’s nominated premises; and
(e) this warranty shall not apply to the Programs.
2. No Products shall be returned to NetComm for repair or replacement under
any warranty provided under the Agreement without NetComm’s prior
written consent.
LIMITATION OF LIABILITY
NetComm will have no liability to its Customers under the above warranties
beyond what is set out in them. NetComm liability under implied warranties
and conditions is limited to that set out in its standard terms and conditions.
SmartModem Reference Guide
iii
Contents
CONTENTS
Introduction............................................................ 1
How to Use This Guide .......................................... 1
Conventions ............................................................ 3
Getting Started........................................................ 5
The AT Commands ................................................ 5
The Attention Code .......................................... 5
Multiple Commands ......................................... 5
The Escape Sequence ........................................ 6
The Repeat Command ......................................7
The Help Command ......................................... 7
Response Codes ................................................ 7
Dialling .................................................................. 8
Dial Modifiers .................................................. 9
Hanging Up ...................................................11
Stored Number Dialling .................................12
Answering Calls.................................................... 13
Selecting Speeds.................................................... 15
Terminal Speeds ............................................. 15
Setting Terminal Speeds ................................. 16
Line Speeds ..................................................... 17
V.34 Modem Typical Settings ........................ 18
V.32bis Modem Typical Settings .................... 19
Flow Control......................................................... 21
RTS/CTS Flow Control ................................... 21
XON/XOFF Flow Control.............................. 21
Transparent XON/XOFF Flow Control .......... 22
Failsafe Flow Control ......................................22
The Inactivity Timer ............................................ 23
The Command Timer ........................................... 23
Configuring the Modem ....................................... 23
Viewing the Current Configuration ................ 24
Testing ................................................................ 25
The Test Timer..................................................... 25
Terminating a Test - &T0..................................... 25
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SmartModem Reference Guide
Local Analog Loopback Test - &T1 .......................25
Local Digital Loopback Test - &T3 .......................27
Grant RDL from Remote Modem - &T4............... 28
Deny RDL from Remote Modem - &T5................ 28
Remote Digital Loopback Test - &T6 ...................28
Remote Digital Loopback with Self Test - &T7 .... 30
Local Analog Loopback & Self Test - &T8 .............32
Error Correction ................................................... 33
Error Correction Protocols .................................... 33
Data Compression .................................................34
Reliable Mode....................................................... 35
Auto-Reliable Mode ............................................. 35
Improving Performance with MNP 10.................. 37
Speed Changes ................................................ 38
Cellular Modem Users .................................... 39
Which Error Correction Do I Use?........................ 39
Increasing Data Throughput with
Error Correction & Data Compression ............. 40
Contents
Digital Simultaneous Voice & Data (Digital SVD) ..... 41
Setting up for Digital SVD ................................... 41
Using the Telephone to make Normal
Voice Connections .......................................... 41
Starting a Digital SVD Connection after you have
Established a Normal Voice Connection ..... 42
Starting a Digital SVD Connection after you have
Established a Normal Voice Connection ..... 43
Security & Encryption .......................................... 44
The Security Menu................................................ 45
Entering Security Password ............................ 45
Adding and Changing Users ...........................46
Removing Users ............................................. 47
Listing Existing Users .................................... 47
The Access Record .......................................... 47
Enabling Modem Security .............................. 48
SmartModem Reference Guide v
Contents
Quitting the Menu ......................................... 49
Callback Security .................................................. 49
Downloading the Security File........................ 51
Uploading the Security File ............................ 51
Encryption............................................................ 52
SuperSecure Advanced Security Mode ................... 54
Entering Key forEach User ............................. 54
Accessing Using SuperSecure .......................... 55
Connection ..................................................... 56
Disconnection ................................................. 56
Enabling Rotating Secondary Keys ....................... 57
Symmetrical Operation .........................................58
Automatic Synchronisation ...................................58
Password Expiry Option ....................................... 58
Entering in Remote ........................................59
Entering in Local ............................................59
Minimum Length ........................................... 59
Additional User Options....................................... 60
Up & Downloading the SuperSecure Database ...... 60
Security Database Lock Option ............................. 61
Outdial Disable Option ........................................ 61
Dial Stored Phone Numbers Only Option............. 62
General Notes on Data Security ............................ 62
Synchronous Modes .............................................. 63
Synchronous Operation .........................................63
Terminal Speeds ............................................. 63
Line Speeds ..................................................... 64
Synchronous Mode 1 ....................................... 65
Selecting..................................................... 66
Dialling...................................................... 66
Hanging Up ............................................... 67
Answering Calls ......................................... 67
Synchronous Mode 2 ....................................... 68
Selecting..................................................... 69
Dialling...................................................... 69
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SmartModem Reference Guide
Hanging Up ............................................... 69
Answering Calls ......................................... 69
Leased Line Operations ......................................... 70
Smart Leased Line Mode ................................. 71
Calling & Answering Using &L1 ................71
Auto Leased Line Operation (&L2 or &L3) ..72
Hanging Up ............................................... 72
Improving the Reliability of
Leased-Line Connections............................. 73
Dumb Mode Operation ........................................ 74
Selecting Dumb Mode .......................................... 74
on Desktop Modems ....................................... 74
on ProRack Modems....................................... 75
Setting up your Modem ........................................ 75
Selecting Communications Speeds
on Desktop Modems ...................................... 76
on ProRack Modems....................................... 77
Hints for Unix Computers & Multiplexers ............ 78
Dialling in Dumb Mode ....................................... 78
Dialling with telephone handset ..................... 79
Using Talk/Data Button to dial ......................80
Using DTR to Dial......................................... 81
Answering Calls in Dumb Mode ........................... 83
Automatic Answering..................................... 83
Manual Answering ......................................... 84
The Option Switches ............................................ 86
Modems with Rear Panel Option Switches ..... 86
Modems without Rear Panel Option Switches 87
ProRack Modems ........................................... 88
Contents
CCITT V.25bis Operations .................................. 89
Selecting V.25bis Operation ................................. 89
Overridden Settings........................................ 90
V.25bis Commands .............................................. 91
Data Formats ........................................................ 91
V.25bis Indications............................................... 91
Dialling ................................................................ 92
SmartModem Reference Guide vii
Contents
Dial Modifiers ................................................ 93
Hanging Up ...................................................95
Stored Number Dialling .................................95
Direct Dialling ...............................................95
Answering Calls.................................................... 96
Selecting Speeds.................................................... 97
Terminal Speeds ............................................. 98
Line Speeds ..................................................... 98
Modem Cable ....................................................... 99
Synchronous Character Encoding .......................... 99
Asynchronous Notes ........................................... 100
BSC Notes .......................................................... 100
HDLC Notes ...................................................... 100
Command Descriptions...................................... 101
Alphabetical Command listing ........................... 101
Full Command Descriptions ............................... 104
V.25bis Commands ...................................... 105
S Registers .......................................................... 228
Introduction ....................................................... 228
Reading and Changing S Registers ..................... 228
S Register Settings and Modem Memory............. 229
Full S Register details .........................................231
viii
Troubleshooting ................................................. 271
Introduction ....................................................... 271
Some Problems and Solutions ............................. 271
Troubleshooting Flow Chart ............................... 275
Testing Your Modem.......................................... 277
Sample Setups ..................................................... 278
Asynchronous Mode............................................ 278
Calling a BBS or EMail System ..................... 278
Using as an Auto-Answer Modem ................ 279
Using Connected to UNIX Computer .......... 281
Using in Leased Line Mode ...........................282
Synchronous Mode .............................................. 283
SmartModem Reference Guide
Appendices ......................................................... 284
Appendix A ........................................................ 284
Modem Response Codes ...................................... 284
V.25bis Indications ...................................... 285
Appendix B ........................................................ 286
ASCII Table........................................................ 286
Appendix C ........................................................ 287
RS-232 Signals ................................................... 287
Glossary ............................................................... 290
Index ................................................................... 315
Contents
SmartModem Reference Guide ix
Introduction
INTRODUCTION
Welcome to the SmartModem Reference Guide, a comprehensive
guide to the efficient use of your modem.
Together with the Installation Guide & Command Card supplied with
your modem, this reference manual provides all the information needed
to make maximum use of your equipment and software.
The SmartModem Family contains a range of different models.
Model Type DSVD SS Rack Voice Series
M7F V.32bis X 5
V8 V.32bis X 5
M11F V.FC X 5
M34F V.34 X 5
288 V.34 X X 6
288D V.34 X X 6
☞ SS = SuperSecure
Rack = Rack version available with SNMP
X.32 is available as an option on some models
Introduction
How to Use This Guide
The SmartModem Reference Guide is divided into the following
sections:
Introduction
❏ Provides you with an easy-to-understand guide to what’s in this
manual and how you can make the most of the information.
Getting Started
❏ A complete description about how to get started using your
equipment, including basic details and more advanced topics.
Testing
❏ Details each of the many tests you can carry out to determine the
working condition of your modem, the telephone line, or the
remote modem.
SmartModem Reference Guide
1
Introduction
Error Correction
❏ Examines and explains the error correction features,
Introduction
Digital SVD
❏ Explains how to use Digital Simultaneous Voice and Data
Security
❏ Examines and explains the data security and encryption
Synchronous & Dumb Modes
❏ Full details on how to use your modem for synchronous operations.
Dumb Mode
❏ Provides product specified information on Dumb Mode operation.
V.25bis Operations
❏ Describes how your modem implements V.25bis and how it
AT Commands
❏ Provides a complete description of all commands available in
S Registers
❏ Introduces you to S Registers and how to use them.
❏ Contains a description of the available S Registers.
Troubleshooting
❏ Provides basic guidelines for solving problems.
Sample Setups
❏ Provides sample setups showing how commands can be combined.
Appendices
❏ The appendices contain useful lists, as well as an ASCII table.
Glossary of Communications Terms
❏ Provides descriptions of modem, facsimile and other
includingV.42bis data compression, of your equipment.
facility.
features of your equipment.
interacts with AT commands.
your modem.
communications terms.
2
SmartModem Reference Guide
Conventions
Throughout this guide, we use certain symbols, typestyles and
conventions to help you. For example, you might find a line that
looks like this:
• Type:
(that is ‘ATI9’ not ‘AT19’)
What you actually type appears in a special typeface:
ATI9
Whatever appears on your screen will also be displayed in this
manual in this special typeface — for example: messages:
CONNECT
When we want you to press the ENTER key, we use a symbol:
ATI9 <E>
<E> (which means ‘and press
ENTER’)
Introduction
Introduction
On some keyboards the
RETURN or ENTER, as appropriate for your keyboard. The same is
true for keyboards showing a symbol, rather than
ENTER.
RETURN = ENTER =
In some cases where the <E> symbol might be confusing, we will tell
you to ‘Press the
When you see the bullet (•), it usually starts an action statement.
We want you to take some specific action, such as:
• Switch your computer on
• Type:
Note that we do not use a (.) full stop after an action statement.
We do that to avoid confusion when you are asked to type
commands and other information.
When we list general information, we use a box (❏), like this:
SmartModem Reference Guide
ENTER key is labelled RETURN. You press
RETURN or
ENTER key’.
ATI9 <E>
3
Introduction
❏ How to begin dialling
❏ Using MNP for error-free communication
Introduction
When we have special information we want you to take NOTE
of, we use a pointing finger (
☞Before proceeding, complete both copies of the Warranty
Information we want you to pay special attention to is placed in
a WARNING box, like this:
DEFAULTS are settings which are preset in the factory. Default
settings are indicated in this guide by the symbol: ■
For example, if the default was AT&G0 in this list:
■ AT&G0 Do not generate guard tones
☞), like this:
form.
WARNING
Regulations require that the modem,
when operating in originate mode, waits no
longer than 30 seconds for a carrier to be
detected from a remote modem.
AT&G1 Generate Guard tones of 550Hz
AT&G2 Generate Guard tones of 1800Hz
There is a Glossary at the back of this Reference Guide to assist
you with unfamiliar words.
4
SmartModem Reference Guide
Getting Started
GETTING STARTED
The AT Commands
The AT commands are a group of special commands recognised
by your modem. These commands derive their name from the
letters AT, which are used to prefix commands. Before continuing:
• Run your communications software and enter local mode (or
terminal mode) at 2400 bps Refer to your communication
software manual for details.
The Attention Code
An AT (sometimes known as the ATtention code) usually
precedes all commands being sent to the modem. It is used to
gain the modem’s attention, informing it that you are about to
send a command. For example:
• Type the command: ATI9 <E>
Your modem’s firmware identity message will appear on your
computer screen. If you type I9 only, your modem will not
respond. If you type AT19, your modem will report an
ERROR.
Getting Started
You may enter the attention code in all upper case, or all lower
case letters, such as:
Multiple Commands
You may place multiple modem commands after an AT provided
the total number of characters does not exceed 80. For example,
a valid command to display the modem’s firmware identity twice
is:
• Type in the command: ATI9I9 <E>
An AT is not required in front of the second I9 command.
You only need one attention code for each
command line. To make this command more readable,
you can add spaces between the two commands:
• Type in the command: AT I9 I9 <E>
The modem will execute the command as if the spaces are not
there.
SmartModem Reference Guide
AT or at
5
Getting Started
The Escape Sequence
When you issue commands to the modem all dialogue is occurring
between your computer and the modem. This situation is
known as local command state.
When you connect to a remote system, dialogue will be occurring
between your computer and the remote system. This is known
as on-line state. Because the modem assumes, after it enters online state, all the data you send it is to be sent on to the remote
Getting Started
modem, it ignores any AT commands you give it while in online state.
To force the modem to return to local command state, enter an
escape sequence. An escape sequence consists of a one second
delay, three + characters typed rapidly and another one second
delay. For example:
• Type: AT&T1 <E>
The modem will enter on-line state (this command actually
causes the modem to enter test mode, but is equivalent to
entering on-line state).
Now try to view the modem’s firmware identity code:
• Type: ATI9 <E>
Your command will be ignored. This is because the modem
assumes you aretyping characters to be sent to a remote
system.
Now enter an escape sequence. Do not type any characters for
one second, type +++ rapidly and wait another full second. The
modem will respond with an OK message to indicate it has
returned to local command state. You will be able to view the
modem’s firmware identity.
Before continuing:
• Type: AT&T0 <E>
This command is used to halt the test.
6
SmartModem Reference Guide
The Repeat Command
The repeat command is used to re-execute the last command
issued to the modem. Issue the ATI9 command and the
modem’s firmware identity code will be displayed on the screen.
• Type: A/
The identity code will appear again.
You don’t have to enter AT before the repeat command. You also
do not have to press the
ENTER key. This is the only modem
command which does not require you to enter AT before it, and
one of the few commands which does not require you to press the
ENTER key. The A/ command is intended primarily for re-
dialling a telephone number that was previously engaged.
The Help Command
Your modem will display information about the AT commands
it supports if you type a question mark (?) in your AT command.
For example:
• Type: AT? <E>
Your modem will display a list of all the commands it
supports.
• Type: AT?DTR <E>
Your modem will display a summary of commands involving
DTR.
• Type: AT?\N3%C2&D2 <E>
Your modem will display summaries of the \N, %C and &D
commands.
Getting Started
Getting Started
Response Codes
Your modem is capable of telling you, with on screen messages,
what it is doing. These messages are known response codes or
result codes, and you will see them from time to time.
For example:
After a command is successfully executed, the response is:
OK
After a connection is established, the response is: CONNECT
A complete list of Response Codes can be found in Appendix A.
SmartModem Reference Guide
7
Getting Started
Dialling
The AT commands may be used to initiate dialling with the
modem. Your modem does not require a telephone handset to
be connected to it in order to dial.
Asynchronous
Local Command State
Getting Started
The D (Dial) command is used to initiate a telephone call. The
most basic form of the D command is:
ATD number
where the number is the telephone number you are dialling.
Having set your communications software for 2400 bps operation:
• Type: ATD01234 <E>
Your modem will begin to dial.
ATD issued
Phone # busy or
connection failed
Connection established
ATO
Asynchronous
On-line State
Escape sequence
entered (+++)
Local Command State
ATH issued
Hang Up
Asynchronous Originate Mode
Carrier lost or
DTR lowered (&D2)
8
SmartModem Reference Guide
Getting Started
☞ If your modem receives a character from your computer while
dialling is being performed, it will immediately hang up,
send a NO CARRIER response message to the computer and
return to local command state.
After a few seconds the message CONNECT will appear on the
screen.
If a NO CARRIER message appears, then your modem has not
been able to make a connection. Check your communications
software is set for 2400 bps operation and your modem is
correctly connected to your computer and the telephone line.
You may use the A/ command to redial.
To hang up the modem, enter an escape sequence (+++). The
modem will respond with an OK message.
• Type: ATH <E>
The modem will hang up.
☞ Your computer must assert the DTR signal before dialling
can start. Usually, this is done by your communications
software. If the DTR signal is lowered at any stage of
communications, after the &D2 command has been issued,
the modem will hang up and return to local command state.
Interpretation of the DTR signal may be changed with the
&D command.
Getting Started
Dial Modifiers
Dial modifiers are characters than can be included in a phone
number to make the modem perform special tasks while dialling.
For example, not all modem users will be using a dedicated
telephone line. Some users will have their modems connected to
PABXs. To allow users of PABXs to operate their modems
successfully, dial modifiers are supported on the modem.
Most PABXs require you to dial 0 or 9 (in order to obtain an
outside line) and wait for a dial tone before dialling the actual
phone number.
SmartModem Reference Guide
9
Getting Started
Using dial modifiers, you can successfully dial the phone number
12345 through a PABX using the command:
ATD0,12345
The , (comma) dial modifier causes the modem to pause for
a short time after dialling 0. This allows most PABXs
sufficient time to obtain a line before dialling.
The factory default delay for the , modifier is two seconds. You
may change the length of this delay if necessary. Its length is
determined by the value in S Register 8.
Getting Started
Another method of making the modem wait for a dial tone is to
include the W dial modifier. The W modifier causes the modem
to examine the phone line to ensure a dial tone has been applied
before dialling starts:
ATD0W12345
If the modem cannot detect a dial tone within the time
specified by S Register 7, the modem will return to local
command state and send a NO DIALTONE message to the
computer (if either the X2, X4, or X5 commands have been
issued).
10
Due to differences with some older telephone exchanges, dial
tone detection may not be possible with your modem. Your
modem will only recognise dial tones between 200 Hz and 600
Hz.
If your telephone line supports tone dialling then a useful dial
modifier is the T modifier. Inserting a T modifier before the
number you are dialling causes the modem to tone dial that
number. For example:
ATDT12345
This will cause the modem to dial the phone number 12345.
The modem also supports a P dial modifier which allows it to
pulse dial. These modifiers may be placed at any point in the
number you are dialling and they may be intermingled in the
same number.
SmartModem Reference Guide
Getting Started
For example, your telephone line may be connected to a PABX
that supports tone dialling internally, but only pulse dialling
externally. You could overcome this problem by using the T
and P dial modifiers in the following way:
ATDT0,P12345
The modem tone dials 0 to request an external line, waits for the
PABX to obtain the line and then pulse dials 12345.
Although most telephone exchanges support tone dialling,
there are still a few pulse only exchanges. If you can hear a
continuous dial tone when you lift the handset, you will probably
be able to tone dial. If you are in any doubt, use pulse dialling.
The modem will automatically pulse dial if you have not
previously included either the T or P modifiers in your phone
numbers. Exchanges that support tone dialling generally support
pulse dialling as well.
More information about dial modifiers can be found in the
Command Descriptions chapter of this guide.
Getting Started
☞ Pulse dialling may not be supported in New Zealand. Refer
to your Installation Guide for details.
Hanging Up
The H command is used to hang up the modem. After you have
finished communicating with another computer you must hang
up your modem. Similarly, you must hang up the phone after
calling another person. If you don’t, no one will be able to call
you and you may even be charged for the length of time the
phone was off the hook.
To hang up your modem:
• Type: ATH <E>
The modem will return an OK response message.
SmartModem Reference Guide
11
Getting Started
Stored Number Dialling
Your modem has the ability to store phone numbers which may
be dialled at a later time. This is similar to ‘abbreviated
dialling’, which may be supported by your telephone.
To store a phone number use the &Z command. For example:
• Type: AT&Z1=012345 <E>
The phone number 012345 will be stored as phone
number one.
Getting Started
The S dial modifier is used to dial a phone number that has been
stored in your modem:
• Type: ATDS=1 <E>
The modem will dial stored phone number one.
☞ Do not include an AT, D command, or S dial modifier in the
stored phone number. If synchronous mode 2 is being used,
the ; (semi-colon) dial modifier should not be included.
Answering Calls
As well as dialling other modems, your modem can answer calls
made to it by other modems.
Your modem is pre-configured to automatically answer any
incoming call, provided it is switched on, is in local command
state, DTR is high and is not performing a test. If you receive
a call on the phone line the modem is connected to, it will answer
the call and attempt to connect to the calling modem.
S Register 0 contains the number of rings the modem will wait
before answering a call. If a value of 4 is placed in S Register 0,
the modem will answer an incoming call immediately after the
fourth ring. If a 0 value is placed in S Register 0, the modem will
not answer an incoming call.
12
SmartModem Reference Guide
Getting Started
The communications standard used by the modem in its attempt
to connect with a calling modem is determined by the B
command.
Carrier
lost or
DTR
lowered
(&D2)
Asynchronous
Local Command State
ATA or
Incoming call
Connection
failed
Connection established
Asynchronous
On-line State
Escape sequence
entered (+++)
Local Command State
ATH issued
Hang Up
Asynchronous Answer Mode
Getting Started
ATO
SmartModem Reference Guide
13
Getting Started
If the phone does ring, and verbal response codes are selected
(ATV1), the modem will issue
of rings stored in S Register 0 is reached. The modem will then
go on line, transmit an answer tone, and attempt to connect to
the calling modem using the communications standard selected
by the B command.
By default the modem is set to B0. B0 is the auto range setting.
Getting Started
This should connect to virtually all communications standards
and normally you do not have to alter this.
As soon as a connection is established, the modem will send a
CONNECT message to your computer and enter on-line state in
answer mode.
RING messages until the number
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SmartModem Reference Guide
Selecting Speeds
R
•
•
The following section describes how to select line and terminal
speeds for your modem.
Your Computer
Terminal
speed
Modem
Modem
Line
speed
Telephone
Exchange
emote
Computer
Getting Started
Getting Started
Line
speed
Terminal
speed
Terminal Speeds
Your modem has the ability to communicate with your computer
at various speeds. (Refer to your Command Card for details on
which speeds are available in your modem.) The modem offers
two speed modes: variable speed mode and constant speed mode.
Constant speed mode forces your modem to maintain the terminal
speed that was selected when you dialled another modem, even
if the connection speed made with the other modem does not
match the terminal speed of your modem and computer.
For example, if your modem connected to another modem at
2400 bps and its terminal speed is 9600 bps, the modem will
maintain its terminal speed at 9600 bps. Because of this, you
must select flow control between the modem and your computer.
To select constant speed mode:
• Type:
For more details on constant speed mode and flow controls, see
the Command Descriptions chapter for a discussion of the \N, B
and &K commands.
AT\N0 <E>
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Getting Started
☞ Some computers cannot cope with receiving data at speeds
Variable speed mode allows your modem to automatically
adjust its terminal speed to match the line speed. For example,
Getting Started
if your modem connects to another modem at 4800 bps and its
terminal speed is 9600 bps, the modem will automatically
change its terminal speed to 4800 bps (and, thus, you or your
software would have to change the speed of your computer to
4800 bps).
If you have variable speed mode and B0, B1, B2 or B9 selected,
the modem will attempt to connect at a speed to match the
terminal speed.
At 300 bps, select B0 or B2 for V.21, or B1 for Bell 103. At
1200 bps, select B0 for V.23, B1 for Bell 212A, or B2 for V.22.
above 19,200 bps. If you wish to run at high speeds, you
should install a COM port that has a 16550 chip in place of
your regular COM port. The 16550 chip allows your
computer to accept data at very high speeds when used with
suitable drivers and software.
Variable speed mode may be selected by:
• Type: AT\N1 <E>
For more details about the variable speed mode, see the \N and
B commands in the Command Descriptions chapter of this
guide.
Setting Terminal Speeds
Your modem can sense the terminal speed of the computer and
automatically change its terminal speed to match. This is
known as ‘auto bauding’, and is done each time an AT command
is issued to the modem.
Your modem can auto baud at 300 bps through 9600 bps,
14,400 bps, 19,200 bps, 28800 bps,38,400 bps, 57,600 bps
and 115,200 bps.
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SmartModem Reference Guide
Getting Started
The R command may also be used to disable autobauding and
lock the terminal speed. Refer to the R command for available
speeds.
Line Speeds
The B command determines the speed at which your modem
connects to another modem. Some or all of the following B
commands are provided by your modem (refer to your modem’s
Installation Guide for details on which communications standards
are supported):
SettingSelection
Command Speed Command Speed
B0 n Auto-Connect B16 V.34 at 14,400bps
B1 Auto-Connect B17 V.34 at 16,800 bps
B2 Auto-Connect B18 V.34 at 19,200 bps
B3 V.21 at 300 bps B19 V.34 at 21,600 bps
B4 Bell 103 at 300 bps B20 V.34 at 24,000 bps
B5 V.23 at 1200/75 bps B21 V.34 at 26,400 bps
B6 V.22 at 1200 bps B22 V.34 at 28,800 bps
B7 Bell 212A at 1200 bps B23 (Reserved for V34bis)
B8 V.22bis at 2400 bps B24 (Reserved for V34bis)
B9 Auto-Connect B25 (Reserved)
B10 V.32 at 4800 bps B26 (Reserved)
B11 V.32bis at 7200 bps B27 V.34 at 2400 bps
B12 V.32 (Non-TCM) at 9600 bps B28 V.34 at 4800 bps
B13 V.32 at 9600 bps B29 V.34 at 7200 bps
B14 V.32bis at 12,000 bps B30 V.34 at 9600 bps
B15 V.32bis at 14,400 bps B31 V.34 at 12,000 bps
Getting Started
In most cases you should select B0, as this setting attempts to
connect at any speed supported by the modem.
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Getting Started
V.34 Modem Typical Settings
Here are some example settings that may be relevant to the way
in which you wish to operate your V.34 modem.
Example 1 - Dialling other modems at the highest possible
speed and/or answering incoming calls.
Getting Started
B Command Setting: B0
Terminal Speed: 115,200 bps
Flow Control: On (&K9 for either RTS/CTS or XON/
Use this arrangement when dialling online information services
or bulletin boards. With these settings, you modem will
attempt to connect at any speed from 28,800 bps to 1200 bps.
These are the default settings of your modem.
If you wish your modem to answer incoming calls, use these
settings. This will allow your modem to connect at any speed
between 28,800 bps and 300 bps. If you are using a software
program that controls the answering of your modem (as some
bulletin board systems do) you may need to issue an ATS0=0
command to disable auto-answering, otherwise issue ATS0=2
to make the modem answer calls after two rings (the default
setting).
Example 2 - Dialling other modems at 19,200 bps (V.34 or
V.FC)
XOFF flow control)
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B Command Setting: B18
Terminal Speed: 57,600 bps
Flow Control: On (&K9 for either RTS/CTS or XON/
XOFF flow control)
You may use this arrangement when dialling online information
services or bulletin boards. With these settings, you modem
will attempt to connect at 19,200 bps, but may change the line
SmartModem Reference Guide
Getting Started
speed if the quality of the telephone line does not support this
speed.
Example 3 - Dialling information services at 1200 bps (or V.22)
B Command Setting: B6
Terminal Speed: 38400 bps
Flow Control: On (&K9 for either RTS/CTS or XON/
XOFF flow control)
Some information services do not provide connections higher
than 1200 bps; these settings allow you to connect to such
services. Problems may also occur if error correction is switched
on; if the information service does not support V.42 or MNP,
issue the \N0 command before dialling.
V.32bis Modem Typical Settings
Here are some example settings that may be relevant to the way
in which you wish to operate your V.32bis modem.
Example 1 - Dialling other modems at the highest possible
speed
B Command Setting: B0
Terminal Speed: 38,400 bps
Flow Control: On (&K9 for either RTS/CTS or XON/
XOFF flow control)
Getting Started
Use this arrangement when dialling online information services
or bulletin boards. With these settings, your modem will
attempt to connect at any speed from 14,400 bps to 1200 bps.
These are the default settings of your modem.
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Getting Started
Example 2 - Dialling other modems at 14,400 bps (or V.32bis)
B Command Setting: B15
Terminal Speed: 38,400 bps
Flow Control: On (&K9 for either RTS/CTS or XON/
XOFF flow control)
Getting Started
You may use this arrangement when dialling online information
services or bulletin boards. With these settings, your modem
will attempt to connect at any speed from 14,400 bps to 1200
bps. Because V.32bis operation is not suitable on poor-quality
telephone lines, we recommend you use these settings with
caution; if you have trouble connecting to another modem using
V.32bis, revert to the settings shown in Example 1.
Example 3 - Answering incoming calls
B Command Setting: B9
Terminal Speed: 38,400 bps
Flow Control: On (&K9 for either RTS/CTS or XON/
If you wish your modem to answer incoming calls, use these
settings. This will allow your modem to connect at any speed
between 14,400 bps and 300 bps. If you are using a software
program that controls the answering of your modem (as some
bulletin board systems do) you may need to issue an ATS0=0
command to disable auto-answering, otherwise issue ATS0=2
to make the modem answer calls after two rings (the default
setting).
XOFF flow control)
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SmartModem Reference Guide
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