Octek SMART MoDeM, VoiceMaster, Socket Rocket Reference Guide

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SmartModem

Reference

Guide

SmartModem

VoiceMaster

Socket Rocket

Revision C

January, 1996

YML212-3

NetComm Code Version V2.65

ISBN 0 947206 95 7

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

SmartModem Reference Guide

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

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.

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;

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

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

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

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.

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

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>

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.

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

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.

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

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:

After a connection is established, the response is: CONNECT

A complete list of Response Codes can be found in Appendix A.

SmartModem Reference Guide

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)

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

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).

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

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.

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

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

SmartModem Reference Guide

Selecting Speeds

•

The following section describes how to select line and terminal

speeds for your modem.

Your Computer

Terminal

speed

Modem

Line

speed

Telephone

Exchange

emote

Computer

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>

15SmartModem Reference Guide

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.

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.

17SmartModem Reference Guide

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)

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.

19SmartModem Reference Guide

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)

SmartModem Reference Guide

Flow Control

Your modem supports RTS/CTS, XON/XOFF and Transparent

XON/OFF flow control. Flow control ensures that data is not lost between your computer and your modem.

Flow control will be ignored when your modem is configured for variable speed mode (AT\N1) or is in local command state.

RTS/CTS Flow Control

RTS/CTS flow control takes place when the modem and computer manipulate the CTS (Clear To Send) and RTS (Request To Send) signals to stop and start data flow. This form of flow control is recommended if supported by your computer and communications software, as it does not interfere with file transfer protocols.

☞ In order for flow control to operate correctly between your

computer and the modem, the appropriate form of flow control must be selected with your communications software. See your communications software manual for details. You must also have a modem cable that connects the RTS and CTS signals of your modem to your computer.

Getting Started

RTS/CTS flow control is selected with the &K3 command.

XON/XOFF Flow Control

XON/XOFF flow control takes place when the modem and communications software transmit XON and XOFF characters to start and stop data flow. This form of flow control is only recommended when your computer or communications software does not support RTS/CTS flow control. The ASCII values of the XON/XOFF characters are 17 (DC1) and 19 (DC3) respectively.

XON/XOFF flow control is selected with the &K4 command.

☞ XON/XOFF flow control should not be used with the

XModem, YModem or SEAlink file transfer protocols.

21SmartModem Reference Guide

Getting Started

Transparent XON/XOFF Flow Control

Transparent XON/XOFF flow control is identical to

normal XON/XOFF flow control except the XON and

XOFF characters which are part of the normal data

stream are encoded to allow flow control with file transfer

protocols such as XModem. The ASCII values of the XON and

XOFF characters are 17 (DC1) and 19 (DC3) respectively.

Getting Started

Transparent XON/XOFF flow control is selected by issuing the

&K5 command.

Failsafe Flow Control

Failsafe flow control is designed specifically for UNIX computers

running the UUCP file transfer protocol. This form of flow

control only affects data being transmitted from the computer

to the modem.

When the modem’s data buffer approaches maximum capacity,

the modem will lower the CTS signal. If the computer does not

pause the transmission of data within a few character durations

of CTS going low, the modem will send an XOFF to the

computer.

When the modem is ready to accept more data from the computer

it will assess CTS. If an XOFF was sent to pause transmission,

the modem will also send an XON character.

☞ Failsafe flow control only affects data being transmitted

from the computer to the modem. Flow control is not supported for data being transmitted by the modem to the computer.

Failsafe flow control is selected by issuing the &K9 command.

SmartModem Reference Guide

The Inactivity Timer

Your modem supports an inactivity timer. When your modem

is on line, if it does not communicate with either the remote

modem or your computer for a specified length of time, it will

hang up and return to local command state

The AT\T command specifies the number of minutes the modem

stays on line when no activity is occurring. The timer may be set

from 1 to 255 minutes. For example:

AT\T5

This allows the modem to be inactive in on-line state for five minutes before hanging up the default time is 0 minutes the

timer is disabled. The inactivity timer is only available when MNP or constant speed mode is selected. It is ignored in variable speed mode.

The Command Timer

If you do not complete an AT command within 60 seconds (that is, type the command and press ENTER), the command will be discarded and an error message will appear. The length of time is controlled by S Register 69 and can be turned off by setting S Register 69 to 0.

Getting Started

Configuring the Modem

Your modem allows you to tailor its operating parameters to suit your own particular requirements.

The modem uses S Registers to alter the configuration profile. Each S Register contains a decimal value to represent a time delay, an ASCII character or the number of times the phone should ring before the modem answers it (the interpretation of each value differs with each S Register).

23SmartModem Reference Guide

Getting Started

The modem allows you to save the contents of the S Registers and certain communication settings under a profile number (0-

3) in non-volatile memory (&Wn). This means the entire configuration profile will be retained after you have switched your modem off.

Getting Started

Viewing the Current Configuration

The modem also has factory default settings stored internally, allowing you to change the communication settings and S Register values and then recall the configuration profile stored in your modem when you originally purchased it.

The factory defaults have been selected so most users will be able to make immediate use of their modem, without the need to change any S Register values.

You may restore your modem to its factory defaults at any time:

• Type: AT&F.

There is no need to press ENTER with this command.

The &V command allows you to view the current configuration of your modem. When you issue the &V command, your modem sends a list of the current AT command and S Register settings to your computer.

SmartModem Reference Guide

TESTING

Your modem has in-built test facilities that allow you to determine whether you are experiencing a failure of either the modem, the telephone line or the remote modem.

The modem’s AA (Auto-Answer) LED will flash whenever a test is being performed.

The Test Timer

The modem has a test timer which provides for the automatic termination of tests. S Register 18 allows you to specify the maximum length of time of any of the five tests available with the modem. The test timer may be set between 1 and 255 seconds or disabled by selecting zero seconds (the default).

If the test timer is disabled, tests must be terminated by issuing the &T0 command.

Testing

Terminating a Test: &T0

The &T0 command is used to terminate any of the tests supported by the modem. If the modem is performing a test and you wish to terminate it:

• Type: AT&T0 <E> The modem will respond with OK, indicating that testing has been halted.

Local Analog Loopback Test: &T1

The Local Analog Loopback test checks the flow of data between your computer and the modem. With this test, the modem loops back any characters you type at the keyboard.

SmartModem Reference Guide

Testing

Modem

Testing

Transmitter

Computer

Receiver

Local Analog Loopback Test

☞ Do not start this test while you are connected to a remote modem.

The local analog loopback test will cause the modem to hang up.

To start the local analog loopback test:

• Type: AT\N0 <E>

This disables error correction.

• Type: AT&T1 <E>

• Type a few sentences

Your screen should display what you are typing.

If your modem passes the test:

• Type an escape sequence

You will be returned to local command state.

Terminate the test by:

• Type: AT&T0 <E>

• Type: AT\N3 <E>

If you have set the test timer, the test will be terminate automatically. An OK message will appear as soon as the timer expires.

☞ If your modem does not pass this test — the message was

corrupted or there was no response from the modem at all — contact your dealer for assistance.

SmartModem Reference Guide

Local Digital Loopback Test: &T3

The local digital loopback test (LDL) allows a remote modem to test its operation. This provides testing of modems which do not support the local analog loopback or remote digital loopback tests.

☞ This test is not available when V.21, V.23, V.32, Bell 103 or Bell

212A communication is selected. Error correction must be switched off prior to starting the test.

Modem Remote Modem

Testing

Receiver

Transmitter

Remote

Computer

Transmitter

Receiver

Local Digital Loopback Test

To start an LDL test:

• Type: AT\N0 <E>

• Type: AT&T3 <E>

The operator of the remote computer should now type a few

sentences to show that the modem is operating correctly. When the remote operator has completed the test, the test may be terminated by:

• Type: AT&T0 <E>

• Type: AT\N3 <E>

An OK message will appear.

If you have set the test timer, the test will be automatically terminated and an OK message will appear when the timer expires.

Testing

☞ The remote modem cannot terminate a local digital loopback

test. The test may only be terminated by the modem which

initiated it.

SmartModem Reference Guide

Testing

Grant RDL from Remote Modem: &T4

The &T4 command configures your modem so it will grant an RDL test if requested by a remote modem. This is the factory default setting.

Deny RDL from Remote Modem: &T5

The &T5 command configures your modem so it will prevent a remote modem from starting an RDL test.

If you request an RDL and the &T5 command has been issued to the remote modem, your modem will return to on-line state without commencing an RDL test.

Remote Digital Loopback Test: &T6

The Remote Digital Loopback test (RDL) is similar in function to the local analog loopback test, except that it tests your modem, the remote modem and the telephone line. If your modem can successfully complete a local analog loopback test, you can be sure that it is not at fault.

☞ This test is not available when V.21, V.23, V.32, Bell 103 or Bell

Computer

212A communication is selected. Error correction must be switched off prior to starting the test.

Modem Remote Modem

Transmitter

Receiver

Transmitter

Remote Digital Loopback Test

SmartModem Reference Guide

To start an RDL you must be connected to a remote system that also supports RDL testing.

The modem’s test modes do not work if error correction is switched on. Prior to connecting to the remote modem, you must disable error correction:

• Type: AT\N0 <E>

Once you have connected to the remote modem:

• Type: +++

• Type: AT&T6 <E>

• Type a few sentences to check that the remote modem is both

receiving and transmitting the characters correctly. Your screen

should display what is being typed. To terminate the test:

• Type an escape sequence

The test will be terminated and you will be returned to local

command state.

• Type: AT&T0 <E>

An OK message will appear.

Testing

If you have set the test timer, the test will be automatically terminate, and an OK message will appear when the timer expires.

☞ If only a few characters are corrupted, you can probably blame

telephone line noise. If the majority of the test you are receiving

is corrupted, either the remote system or your modem is to

blame. Perform a local analog loopback test to check the

operation of your modem.

SmartModem Reference Guide

Testing

Remote Digital Loopback With Self Test: &T7

The remote digital loopback and self test is similar to a remote digital loopback, except the modem performs all the testing for you.

☞ This test is not available when V.21, V.23, V.32, Bell 103 or Bell

212A communication is selected. Error correction must be switched off prior to starting the test.

Testing

Computer

Remote Digital Loopback & Self Test

Remote Modem

Receiver

Transmitter

Message

Injector

Error

Counter

Modem

Transmitter

Receiver

To begin an RDL with self test, you must be connected to a remote system that supports RDL testing.

The modem’s test modes do not work if correction is switched on. Prior to connecting to the remote modem, you must disable error correction:

• Type: AT\N0 <E>

Once you have connected to the remote modem:

• Type: +++

• Type: AT&T7 <E>

Your modem will begin to send a defined data pattern to the remote system, which will loop the data back to your modem.

SmartModem Reference Guide

To terminate the rest:

• Type: +++

• Type: AT&T0 <E>

• Type: AT\N3 <E> The number of errors detected by the modem will be displayed. An error count of 255 indicates that 255 or more errors occurred during the test.

If you have set the test timer, the test will be automatically terminated, and an OK message will appear when the timer expires.

Testing

SmartModem Reference Guide

Testing

Local Analog Loopback & Self Test: &T8

The local analog loopback and self test is similar to the local analog loopback except the modem performs all the testing for you.

Modem

Testing

Computer

Local Analog Loopback & Self Test

To start this test:

• Type: AT\N0 <E>

• Type: AT&T8 <E>

Your modem will begin to loopback a defined data pattern.

To terminate the test:

• Type: AT&T0 <E>

• Type: AT\N3 <E>

The number of errors detected by the modem will be displayed. An error count of 255 indicates that 255 or more errors occurred during the test.

Message

Injector

Error

Counter

Transmitter

Receiver

If you have set the test timer, the test will be automatically terminated, and an OK message will appear when the timer expires.

☞ The ProRack M7F+X32 does not support any V.23 test modes. ☞ The ProRack M4F+X32 does not support any test modes in

V.23, V.21 or Bell 103.

SmartModem Reference Guide

ERROR CORRECTION

Error Correction Protocols

This section examines the error correction and data compression features of your modem. The modem offers both V.42 (LAP-M) and MNP Protocol™) error correction protocols. These protocols allow data errors to be detected by the receiving modem, provide flow control between remote systems and improve the overall throughput of data transfers.

Your modem also supports V.42bis and MNP5 data compression. V.42bis is a high performance data compression enabling you to speed up, theoretically by four times, data throughput on some types of data. MNP5 allows you to speed up data throughput by up to two times on some types of data.

☞ Australian Modems: Before dialling into an AUSTPAC

V.22 or V.22bis service, error correction must be disabled using the \N0 command.

(Microcom Networking

Error Correction

Correction

Error

Two types of error correction protocols are offered by your modem; V.42 (or LAP-M) and MNP.

☞ Error correction protocols are not available when a V.23

connection is established.

V.42 is an international standard for error correction between modems. V.42 ensures any errors introduced into your data by telephone line noise is automatically corrected before it is received by your computer. Because V.42 is a CCITT standard, it has become very popular in modems all over the world. V.42 also supports a fallback mode to MNP, in order to remain compatible with modems introduced prior to V.42.

SmartModem Reference Guide 33

Error Correction

Error

Correction

Before V.42 existed, MNP was the de-facto standard for modem error correction. MNP classes 2-4 are supported by your modem for error-correction (an additional class of MNP is supported for data compression). Because MNP is a far less complex error correction protocol than V.42, it outperforms V.42. The section titled “Which Error Correction Do I Use?” provides more information about the performance and compatibility merits of V.42 and MNP.

The \N command is used to select the type of error correction used by your modem.

Data Compression

Two forms of data compression are supported by your modem; V.42bis and MNP 5.

V.42bis is based on the Lempel-Ziv compression technique (similar to the techniques used by PC compression programs) and can work with both V.42 and MNP. V.42bis is very good at compressing data that has repetitions of sequences of characters. For example, in an English sentence there are usually repetitions of ‘ions’ or ‘ings’ or ‘ere’; V.42bis works by creating a library of these repetitions and substituting small symbols for them. V.42bis is also able to switch off data compression if the type of data being sent is unsuitable for compression.

MNP 5 is MNP’s stable-mate; it uses ‘run length encoding’ and a variation of the Huffman compression technique. It can double your data throughput on some types of data and MNP 5 works best when there are lots of characters repeated in sequence or a particular character repeated. For example, if you have a file which contained 50 zero characters in sequence MNP 5 will do a good job of compressing them (in some instances, better than V.42bis) – this is run length encoding. Or, if you had a text file where every second character was an ‘i’ and the other characters were random, MNP 5 would again out-perform V.42bis (in this instance, Huffman coding provides superior compression). However,

SmartModem Reference Guide

MNP 5 does not employ V.42bis’ automatic switching techniques. If the data you are sending is not suitable for compression (for example, an application file or a graphics file), it can actually take longer to send than if data compression was not being used.

For this reason, it is best to use V.42bis whenever possible. If the modem you connect to does not support V.42bis, it is best not to use MNP 5 unless you are only transferring plain text information. If possible, use one of the many popular data compression programs available for computers to compress applications, graphics and other non-text files.

The %C command is used to select the type of data correction used by your modem.

Reliable Mode

Reliable mode allows the modem to use error correction to connect to another modem. If the modem you attempt to connect to does not support a compatible method of error correction, your modem will hang up and return a

CARRIER message.

Error Correction

Correction

Error

Use \N6 to select V.42/MNP reliable mode, \N4 to select V.42-only reliable mode or \N2 to select MNP-only reliable mode.

Auto-Reliable Mode

Auto-reliable mode allows your modem to use V.42 or MNP if the remote modem also supports these. If the remote modem does not support a compatible type of error correction, your modem will fallback to either constant speed or variable speed mode.

☞ The \J command determines whether your modem falls

back to constant speed or variable speed mode.

SmartModem Reference Guide 35

Error Correction

Error

Correction

\N3 selects V.42/MNP auto-reliable mode and \N5 selects V.42-only auto-reliable mode. Your modem supports special CONNECT messages for connections made with either reliable or auto-reliable modes. When the AT\V1 command is issued and your modem connects in either reliable or auto-reliable mode, one of the following messages will be sent to your computer.

NUM/VERBAL 20 CONNECT/REL 300bps connection with error correction 22 CONNECT 1200/REL 1200 bps connection with error correction 23 CONNECT 2400/REL 2400 bps connection with error correction 24 CONNECT 4800/REL 4800 bps connection with error correction 25 CONNECT 9600/REL 9600 bps connection with error correction 26 CONNECT 12000/REL 12000 bps connection with error correction 27 CONNECT 14400/REL 14400 bps connection with error correction 28 CONNECT 7200/REL 7200 bps connection with error correction 43 CONNECT 16800/REL 16,800 bps connection with error correction 44 CONNECT 19200/REL 19,200 bps connection with error correction 45 CONNECT 21600/REL 21,600 bps connection with error correction 46 CONNECT 24000/REL 24,000 bps connection with error correction 47 CONNECT 26400/REL 26,400 bps connection with error correction 48 CONNECT 28800/REL 28,800 bps connection with error correction 49 CONNECT 38400/REL 38,400 bps connection with error correction 50 CONNECT 57600/REL 57,600 bps connection with error correction 70 CONNECT 76800/REL 76,800 bps connection with error correction 71 CONNECT 96000/REL 96,000 bps connection with error correction 72 CONNECT 115200/REL 115,200 bps connection with error correction 73 CONNECT 230400/REL 230,400 bps connection with error correction

☞ The ProRack M7F supports eight special connect messages

20 to 28. The ProRack M4F supports three Special Connect Messages 20 to 23. When the AT\V0 command is issued (default), your modem will generate standard CONNECT messages for both normal and error-corrected connections. If the X0 command has been issued, the CONNECT/REL will be the only ‘error correction’ response code generated, regardless of the connection speed.

☞ Issue the %U1 command if you want your modem to

issue CONNECT/LAP-M response codes when a V.42 connection is established.

SmartModem Reference Guide

The \V8 command will display details of the error correction and data compression negotiated with the remote modem. This information is displayed immediately before the CONNECT message.

The \V9 command will display details of the error correction and data compression negotiated with the remote modem as well as diagnostic information. This information is displayed immediately before the CONNECT message.

Improving Performance with MNP 10

MNP 10 is neither an error correction or data compression technique. MNP 10 works in conjunction with error correction and data compression to improve the performance of your modem when operating with poor or varying quality telephone lines (as sometimes found with overseas or cellular telephone connections).

With MNP 10 operating, your modem can automatically resize the MNP packets, depending upon the line quality. When an MNP connection is established, data is transferred in small ‘chunks’ known as packets. When the line quality drops, MNP 10 reduces the size of packets being transferred in order to maintain data throughput. MNP 10 will increase the packet size to take advantage of improved line quality.

Error Correction

Correction

Error

If the line quality becomes very good or very bad, MNP 10 can automatically step between line speeds. MNP 10 attempts to use the highest speed applicable to the quality of the telephone connection. If the telephone line quality drops while you are connected to another MNP 10 modem, thus introducing errors into your data, and the smallest packet size is being used, the modems will ‘step-down’ in speed until the error rate become acceptable. Similarly, if the line quality improves and the modems are using the largest packet sizes, the modems will ‘step-up’ in speed until the best compromise of error rate and line speed is found.

SmartModem Reference Guide 37

Error Correction

Error

Correction

MNP 10 will also make multiple attempts at establishing an error-corrected connection to another modem (more so than MNP 2-4). This gives you a better chance of making a connection when operating with poor line quality. If the telephone line drops out, MNP 10 will attempt to reconnect up to the maximum time permitted by your country’s telecommunications rules. Thus, if there is a short line dropout, MNP 10 will provide minimal interruption whereas other modems will disconnect entirely.

MNP is the only type of error correction allowed with MNP 10 and is only available when connected to another modem that supports MNP 10. The #K command is used to select MNP 10.

Speed Changes

Although MNP 10 is able to cope with bad telephone connections, your modem must be able to first make a connection with another modem before it can make use of MNP 10. For this reason you may wish to use the AT%H1 command to force your modem to connect at 1200 bps and then ‘upshift’. Most telephone lines will cope with V.32 or V.32bis connections, however connecting at 1200 bps will ensure you make a connection. You may also use the J dial modifier to force your modem to make the initial MNP 10 connection at 1200 bps.

When MNP 10 changes line speed (either up or down) there will be a slight interruption to your communications. For this reason you should always use flow control to ensure data is not lost when MNP 10 changes line speed.

If you wish to establish the connection prior to MNP 10 upshifting or downshifting, issue the %H9 command. This allows you to use the connection before MNP 10 attempts to change the connection speed.

SmartModem Reference Guide

Cellular Modem Users

If you are making modem calls with a cellular phone, issue the AT#K2 command. This tells MNP 10 to try even harder to maintain the connection if your cellular call momentarily drops out.

Which ErrorCorrection Do I Use?

Your modem supports the following combinations of error correction and data compression.

Error Correction

Data Compression

Extended Services

Error Correction

V.42bis

V.42 MNP 2-4

MNP 5

With such a choice, you may be wondering which combination you should be using. The table below shows the relative performance of each combination of error connection and data compression.

MNP 2-4

V.42

MNP 2-4 & MNP 5

V.42 & V.42bis

MNP 2-4 & V.42bis

Good Better Best

MNP 10

Correction

Error

If you are connecting to various makes and models of modems, V.42/V.42bis auto-reliable mode is probably the best alternative (AT\N3%C2). V.42/V.42bis auto-reliable mode will also connect to another modem that supports MNP with V.42bis data compression. For overseas or cellular connections, use MNP 10 if possible (AT\N3%C2#K1).

SmartModem Reference Guide 39

Error Correction

Error

Correction

Increasing Data Throughput with Error Correction & Data Compression

Data throughput refers to the amount of data being transferred. Error correction and data compression allow you to increase data throughput in comparison to if error correction and data compression were not selected.

To allow error correction and data compression to operate with the highest possible throughput, the terminal speed of your modem (the speed it communicates with your computer) must be higher than the line speed (the speed it communicates with the remote modem).

The best way to operate with error correction and data compression is to set your modem for a constant speed of 19,200 bps, 38,400 bps or higher (set the terminal speed of your computer to 19,200 bps, 38,400 bps or higher and issue the command AT\N3 to the modem) with flow control. RTS/CTS flow control is the preferred form of flow control. Your communications software must also be set to use the same type of flow control.

Your Computer

Modem

38400 bps or 19200 bps with flow control

A typical setup to allow maximum throughput with a V.32 or V.32bis modem. Command = ATB0\N3%C3 (or %C1) X4 \V1&K3 (or &K4)

9600 bps

☞ Some computers cannot cope with receiving data at speeds

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

SmartModem Reference Guide

DIGITAL SIMULTANEOUS VOICE &

DATA (Digital SVD)

Digital SVD enables a user to transmit and receive data while carrying on a voice conversation with the remote user. No additional controls or commands are needed. The voice and data streams are separated within the modem and appear to the user to be operating on different telephone lines.

Digital SVD mode is ON by default but can be turned off using AT-SSE0 (-SSE1 to turn back on again).

Setting up for Digital SVD

You need to connect a telephone to the connector on the rear of the modem. The phone connector is the smaller of the two connectors and you will need an adaptor cable to use it.

Digital SVD

Using the Telephone to make Normal Voice Connections

❑ You may use your telephone as a normal telephone. Simply

pick up the handset and dial.

❑ On incoming calls the modem will ring instead of the

attached telephone if Digital SVD is enabled. It is not possible to make the phone ring due to isolation requirements.

❑ If the modem has auto answer turned off (ATS0=0), simply

pick up the telephone and talk.

❑ If S0 is set greater than 0, you need to pick up the telephone

before the specified number of rings or the modem will auto answer the call and try to start a data connection. Set S0 to 7 to allow 20 seconds to answer the phone.

SmartModem Reference Guide

Digital Simultaneous

Voice & Data

Digital SVD

Starting a Digital SVD Connection after you have Established a Normal Voice Connection

❑ To start a Digital SVD connection after you have established

a voice connection, either user simply has to type ATD. A special ringing signal will be generated by the modem

❑ If you are the answering modem you may type ATA to start

the data connection from your side or simply let the modem count out the number of rings specified by S0 after which it will auto answer.

❑ The modems will procede with a V.34 handshake and then

enter Digital SVD mode. You may now talk and send data simultaneously. If either telephone hangs up, the modems will drop back to data mode (the other telephone will give a call drop-out indication like a busy tone).

❑ If you wish to re-establish the voice connection simply pick

up the telephone again. If both telephones have hung up, you may re-establish the voice connection by picking up the handset. This will cause the other modem to ring.

Voice & Data

Digital Simultaneous

❑ If you enter ATH or drop DTR, the data connection will

terminate and you will drop back to normal voice mode. If either party then hangs up the link will be terminated.

SmartModem Reference Guide

Digital SVD

Starting a Digital SVD Connection after you have Established a Data Connection

❑ If you have not picked up the handset the modem behaves like

a normal data modem. To establish a data connection issue the

ATD <number> command as per usual.

❑ After the data connection has been established you may open

the voice link by picking up the telephone handset. This will

send a signal to the remote modem that will cause its speaker to

generate a ringing signal.

❑ When the remote user picks up his telephone the voice

channel will be established and you will be in Digitsal SVD

mode.

☞ Digital SVD digitises the voice signal and multiplexes (mixes) it

with the data signal. The data transmission rate will drop while you are talking. However in periods of silence the data performance will be almost the same as a non Digital SVD data link.

Digital Simultaneous

Voice & Data

Because of the digitisation process there will be a delay in the voice signal. This should not be long enough to cause problems.

☞ Since the telephone is powered by the modem the telephone will not

operate if the modem is not powered on. If there is a power failure remove the phone line from the modem and connect it directly to the telephone if you wish to receive incoming calls or make outgoing calls (unless you have a mains powered phone in which case the phone will not work until the power is restored).

The loudness of the ringing signal can be adjusted via S Register 76. The pitch of the ringing signal can be adjusted via S Register 77.

SmartModem Reference Guide

Security & Encryption

Your modem has many sophisticated security features. They are discussed in this section. Your modem limits caller access by means of user names and passwords. User names and passwords are stored in the modem’s non-volatile memory.

The amount of memory your modem has reserved for this function depends on the model. The M34F and rack modems have 20Kbytes whilst other models have 1.2Kbytes. With typical length user names, passwords and commands over 600 users can be saved in 20Kbytes (40 in 1.2Kbytes)

With each user name and password a modem command of up to 30 characters may be specified. This allows the implementation of callback to users. Callback is where the modem rings a specified phone number. Even if an unauthorised caller manages to break the modem’s security, that caller must be connected to the phone number specified in the remote modem's database.

SECURITY & ENCRYPTION

Security &

Encryption

Also discussed in this section is the topic of DES (Data Encryption Standard) encryption, which allows you to encrypt data being passed to a remote modem.

SmartModem Reference Guide

Security & Encryption

The Security Menu

All additions and changes to your modem’s user and password lists are performed through the Security Menu. This menu is displayed when you use the #S command.

• Type: AT#S <E>

A prompt will appear: Enter Security Password: When you first receive your modem, all passwords will be set as a single ENTER.

• Press the ENTER key The Security Menu will be displayed:

SECURITY MENU

0 = Quit 1 = List Users 2 = Add or Change Users 3 = Delete All Users 4 = View Access Record 5 = Reset Access Record 6 = Security OFF 7 = Security ON 8 = Change Security Password 9 = Encryption Controls A = Stored Phone Numbers Displayed B = Supressed C = Set Password Expiry Days E = Minimum Password Length D = Download Security File to host U = Upload Security File from

host L = Encryption Parameters/Keys LOCK F = FREE Encryption and Dial

Enable

K = OutDial Disable M = Dial Stored Phone Numbers Only Access Security: ON Security Database and Security Mode: FREE Stored Phone Numbers: SUPRESSED & LOCKED OutDial: STORED NUMBERS ONLY Enter Security Function:...

Encryption

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Entering a Security Password

You may choose to have a dedicated security password, thus changing the password assigned for the first security user. To enter a new security password:

• Select Option 8 from the Security Menu <E> You will be prompted to enter a new security password. Your modem is case insensitive. Up to 8 characters may be used, including spaces.

When you enter your password, each character will appear on the

screen as a # character.

• Type in your new password <E> You will be prompted to re-enter the new security password.

• Type in your new password again <E>

SmartModem Reference Guide

Security & Encryption

Your new password will be stored in your modem’s non-volatile memory.

Adding and Changing Users

Your modem allows you to add new users and change existing users. Selecting option 2 on the Security Menu will result in a prompt:

Enter Name:

To add a new user:

• Type in the name of the new user <E> User names must not be longer than 30 characters. They are

case insensitive. To change an existing user:

• Type in the name of the user you wish to change <E> You will be prompted to enter a new name.

• Type in the new name <E>

• If the user is found you will be given the option to change the password, delete the user or zero his access counters.

If you are adding a new user or changing a user, you will be prompted for a new Password (maximum characters = 15).

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The modem will now prompt you to enter a modem command. Modem commands consist of up to 30 characters and may include spaces. When you enter a new command, the previous command will be overwritten.

☞ Do not include an Attention Code (AT) with your command.

Your modem automatically places an AT at the start of this command when it is executed.

If you do not want to specify a modem command or want to leave the current command as it is:

• Press ENTER

If you want to remove the existing command but do not wish to replace it with another command:

• Press the Spacebar <E>

See details on Callback Security later in this section for more information about using commands with your user names.

SmartModem Reference Guide

Security & Encryption

Removing Users

Your modem allows you to remove individual users or all the users currently stored in your modem. To remove an individual user:

• Select option 2 from the Security Menu You will be prompted to enter a new user name.

• Type in the name of the user you wish to delete <E> If the user is found, select the 'D' option to delete.

To delete all the users stored in your modem:

• Select option 3 from the Security Menu You will be prompted to confirm that you wish to remove all user names, passwords and commands

• Press Y <E>

Listing Existing Users

To list all user names, and commands.

• Select option 1 from the Security Menu <E> Your modem will list the user names. Passwords are never displayed.

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☞ Your computer must be capable of displaying at least 80

characters per line for the user list to be displayed in its correct format.

The Access Record

Selecting option 4 and option 5 from the Security Menu allows you to view and change the access records. Your modem keeps a tally of the number of successful (granted) and unsuccessful (denied) attempts to connect to your modem using each user name.

Your modem allows every caller three attempts to enter the correct user name and password. If the caller cannot correctly enter the password, a record is made by your modem that an unsuccessful attempt has been made to use that particular user name.

SmartModem Reference Guide

Security & Encryption

If the number of unsuccessful calls for any user name reaches 255, that user name will be locked and callers will no longer be able to use it, even if the correct password is used. You will not be able to use that particular user name until the access record for all users has been reset.

If, however, the caller does correctly enter the password, your modem records that a successful attempt was made to connect with that user name.

You should regularly check the number of successful and unsuccessful attempts to connect to your modem.

• Select option 4 to view the access record <E>

An unusually high number of unsuccessful attempts to connect with a particular user name may indicate someone is trying to violate your modem’s security. Over a period of many months one of the security users may legitimately accumulate 255 errors, in which case, your modem will automatically lock that user. If this occurs, select option 2, enter the user's name and select the Z option to clear his access record. Each attempted access with an unknown name increments the 'Invalid Usernames Received' count at the top of the list.

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Enabling Modem Security

Selecting option 6 or option 7 allows you to disable or enable your modem’s security mode. With security mode enabled, whenever your modem answers an incoming call it will demand the caller enter a user name and password — the following message will appear on the caller’s computer screen:

Enter Name:

If only one of the modems is configured to use error correction, there will be a slight delay between the time the modems connect and when the caller is asked to enter his user name.

SmartModem Reference Guide

Security & Encryption

When the caller enters his name all characters will be displayed as # characters. The caller is allowed three attempts to correctly enter his name. Your modem is not case sensitive to user names.

If the caller enters a valid user name, your modem will ask the caller to enter the password associated with that user name.

Enter Password:

If the caller enters his password correctly, your modem will send the message ACCESS GRANTED and the caller will have access to the computer connected to your modem.

If the caller cannot, within three attempts, enter the correct user name and password, your modem will send the message ACCESS DENIED and will hang up.

Quitting the Menu

The Quit Security Menu option allows you to return to local command state from the security menu.

• Press 0 <E>

Your modem will issue an OK message. You will be returned to local command state.

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Callback Security

As mentioned earlier, your modem allows you to specify a modem command with every user name and password. This feature allows you to implement modem callback. Callback means that after a caller has successfully connected, your modem will hang up and then dial the caller.

Even if an unauthorised caller successfully connects to your modem, that caller will have to be using the phone line which your modem is going to call back.

Three commands are required to implement callback. First, you must hang up your modem with a H command.

SmartModem Reference Guide

Security & Encryption

Before your modem can call the caller back, it must wait for the caller’s modem to hang up and return to local command state. S Register 27 contains a value representing the number of seconds your modem will wait before commencing dialling. The default value for this register is 0 — your modem will begin to dial as soon as it receives a dial command.

It is necessary, therefore, to place another value in S Register 27 to allow the caller’s modem sufficient time to hang up before your modem begins to dial. A 30-second delay should be sufficient time to allow most modems to hang up, so place an S27=30 in the command.

Using a 30-second delay means the telephone exchange, in most cases, will disconnect the call. This ensures unauthorised callers cannot ‘fool’ callback security by not hanging up after your modem hangs up. Alternatively, contact your telephone company — some telephone companies offer an automatic disconnect facility, which assumes a caller cannot remain off-hook after the modem has hung up.

Place a D command and the caller’s phone number in the command. Assuming the caller’s phone number is 1234567, you will now have a command which looks like this:

H S27=95 D1234567

Security &

After the user has been called back and has completed the call, your

Encryption

modem will hang up, automatically issue an ATZ command to restore all the stored settings and return to local command state, ready to answer incoming calls.

☞ UK Modems. Telephone exchanges in the UK may not hangup

☞ If security is enabled, the answering modem will not assert DCD

after 30 seconds. Consult the supplier of your telephone line for a possible solution.

or DSR until a valid user name and password are received. If \Q5 is selected, CTS will not be asserted until a valid user name and password are received.

SmartModem Reference Guide

Security & Encryption

Downloading the Security File

Selecting option 'D' from the security menu will enable a dump of the security database to your computer for storage or editing. You will be asked to type 'Y' to start the download.

The file format is: "<user name>", "<password>", "<command>", nnn, mmm CR LF where nnn and mmm are the 3 digit Granted and Denied Access Counts and CR and LF are Carriage Return and Line Feed. The last entry has only a CR LF

☞ The download will take place at the current terminal

speed.No flow control is acknowledged. If your computer cannot accept the file at the current data rate exit security and autobaud to a lower speed.

Example: "FRED", "NURK", "HS27=30DT3277502", 000, 000 is a valid entry.

Uploading the Security File

Selecting option 'U' from the security menu will enable a security file in the format described under the Download command to be uploaded into the modem.

You will first be warned that your existing database will be overwritten and then told to start uploading the file.

When the upload is finished the modem will return to the security menu.

The upload will take place at the current terminal speed. The modem can accept data at 115Kbps.

☞ If the data is not in the correct format, the file can be

corrupted, so edit with care and always keep a copy of the unmodified download file.

SmartModem Reference Guide

Encryption

Security &

Security & Encryption

Your modem supports Data Encryption Standard (DES) encryption. DES encryption allows you to encrypt data being passed to a remote modem. The remote modem must support Cipher Feedback (or CFB) DES encryption in order to decrypt the data sent from your modem.

The #E1 command is used to select DES encryption.

The modem requires you to enter an encryption Key and an Initial Value. These are two 16-character hexadecimal numbers. Both the Key and Initial Value are specified by the user, making the encrypted data virtually impossible to decrypt without access to the Key and Initial Value.

Both modems must have DES encryption and error correction selected and must use the same encryption Key and the same Initial Value.

Encryption

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Encryption

WARNING

Only use a reliable error correction mode when

using DES encryption. This will ensure you will

only establish encrypted connections. Refer to

the \N command (in the Commands sections of

this guide) for details of the reliable error

correction modes supported by your modem.

To enter the DES Key and Initial Value:

• Type: AT#S <E>

If your modem offers security features the Security Menu will appear (refer to the start of this chapter):

• Type: 9 <E>

You will be prompted with the following message: Enter Current DES Key

SmartModem Reference Guide

Security & Encryption

If your modem does not offer security features the Security Menu will not be displayed — you will be prompted to type the current DES key. The default DES Key is 16 zeros. If you have not entered a Key yet:

• Type in 16 zeros <E>

• Type in the Key previously stored in the modem <E> When you enter the Key, each character will appear on your computer screen as the S character.

After successfully entering the Key, the Encryption Controls Menu will appear on your screen. ENCRYPTION CONTROLS MENU

1 = Enter DES Key 2 = Enter DES IV - initial value 0 = Quit Enter Encryption Function :

The Encryption Controls Menu allows you to alter the Key or IV (Initial Value).

• Enter the Key and Initial Value as a 16-character hexadecimal number <E> You will be prompted to re-enter the Key and Initial Value,

to verify the correct Key and Initial Value has been entered. You may then return to local command state.

• Select the Quit option from the Encryption Menu

• Select the Quit option from the Security Menu

To enable DES encryption, issue the AT#E1 command. The next time your modem establishes a connection with another modem, it will encrypt outgoing data and attempt to decrypt incoming data.

☞ For countries other than Australia, DES encryption is only

available to end users who meet the security requirements of the Australian Department of Defence. Contact your modem supplier for details of making application for a DES equipped modem to be supplied to you.

SmartModem Reference Guide

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Security & Encryption

SuperSecure Advanced Security Mode

Some SmartModems now include SuperSecure mode. SuperSecure mode allows you to :

❑ Have an individual password and an individual DES KEY. ❑ Automatically change the DES key in a random manner after

each connection without the keys ever being knowable.

❑ Have a different password on the answering modem to the

originating modem.

❑ Timed expiry of passwords.

With these new features, a link between two modems will be very secure. No other modem can dial either modem and connect because the third party will not know the keys of the other users, even if both passwords are known.

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Encryption

Entering a Key for Each User

• Enter AT#E2 to enable SuperSecure mode

• Select the security menu using AT#S

• Enter the security password to gain access to the security menu

• Set up the modem's primary DES KEY and Initial Value (IV) as per standard DES setup

• Select Option 2 to add new users

• Enter the username

• Enter the password to be used by your modem (not necessarily the same as the password on the modem you are going to dial)

☞ Do not use a / character in any password, because this

character is reserved

• When the modem prompts you for a command, do not enter a command because you will not be prompted for the DES KEYS

SmartModem Reference Guide

Security & Encryption

• Enter the 16 hex digit DES secondary KEY for the user, all

16 digits must be keyed

• Enter the 16 hex digit DES secondary Initial Value (IV) for

the user, all 16 digits must be keyed

• Enter the 2 hex digit Key Encryptor (KE) for the user, both

digits must be keyed

☞ The Key, IV and KE can have any value but must be exactly

the same on both answering and orignating modems.

☞ For maximum security do not use keys or initial values that

have easy to remember values.

☞ A KE of 00 turns off random key rotation.

• Enter as many users as you wish whilst in this mode

• Press ENTER at the username prompt to return to the menu

☞ You do not have to turn security on to use SuperSecure. The

#E2 option forces it on always.

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• Enter 0 to exit the security menu

☞ The remote modem must not only support SuperSecure but

must also have a matching username/password and KEYS before access can be gained.

Accessing a System Using SuperSecure

If both your modem and the remote modem have been correctly setup you can:

❑ Dial the remote system. ❑ The modems will connect and enter security dialog mode

using the modem's primary key.

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Security & Encryption

❑ This key must be the same for both modems.

• Enter your username

• Press ENTER

• Enter your user password stored in the remote modem then '/'

• Enter your password stored in your modem

• Press ENTER ☞ You may backspace to correct errors but you will not be able

to see what is typed since all characters are echoed as #

• Do not use the / character in any password

• If the password is the same on both modems then only one password needs to be entered

Connection

❑ You will then CONNECT if the username, both passwords,

all of the KEYS, IVs and KEs match.

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Disconnection

Encryption

❑ The data will be correct and error free, but encrypted on the

line using a KEY unknown to anyone.

❑ If the primary DES KEY mis matches you will not be able to

read the "username" prompt.

❑ The modems will disconnect if:

• The secondary key, IV or KE mismatches (you will also receive a message)

• An error corrected link cannot be established

• Wrong username and/or password is used. You will be given another two changes to enter them before the modem disconnects

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Security & Encryption

Example:

ATDT 456 4321 RINGING RINGING Enter name: MarkStein Enter password: Fudge/Vanilla Access granted

• 'Fudge' is Mark Stein's password on the remote system

• 'Vanilla' is the password on the local modem

• 'Access granted' confirms that the passwords are correct

• Secondary keys mismatch if the secondary KEY, IV or KE are different

Enabling Rotating Secondary Keys

❑ If you enter a KE of 00 for the user, then the secondary key

will remain the same for each connection.

❑ If the KE is not 00 then this value is used as a seed to create

a random new secondary key for the user on each connection.

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❑ After the initial connection is made with the KEY, IV and

KE you have entered, these values will change on both modems to new values which are not accessible by any means.

❑ If an event occurs that corrupts the KEY, IV or KE on either

modem, then both modems will have to be manually set back to a known starting point.

☞ To ensure random unknown keys, make two connections

between the secure modems after they have been initialised.

SmartModem Reference Guide

Security & Encryption

Symmetrical Operation

❑ Either modem can originate the call ❑ Remote modem's password is first. ❑ Local modem's password is second

Automatic Synchronisation

❑ The keys only change after a successful connection is achieved

at both ends.

❑ If either modem drops out during the security handshake

before the CONNECT message, the modems will automatically resynchronise on the next connection.

Password Expiry Option

You may specify the number of days you have before the password must be changed. By default this option is OFF, to enable it select the C option from the security menu. You will then be prompted for the number of days before a password expires (1255 days). The access record (Option 4) displays the password age limit and the age of each user's password.

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Encryption

❑ When a password is within 5 days of expiry a message will be

given before the connect message.

❑ After the password has expired, you will be informed and will

not be allowed another connection until a new password is entered. The access record also notes if you have been informed of the expiry.

❑ Either the remote or the local password or both may expire. ☞ There is no real time clock inside the modem. When the

modem is turned off the clock stops. Therefore the expiry timers actually time the number of days that the modem is turned on and not elapsed days

SmartModem Reference Guide

Security & Encryption

Entering a Password in the Remote Modem's Database

When connected in SuperSecure, you may change your password.

• Enter **** with a 1 second guard time on either side of the stars

• Enter your current password

• Enter your new password

• Verify your new password

• You will then be returned online

Entering a New Password in the Local Modem's Database

When connected in SuperSecure, you may change your password by

• Enter in the escape sequence +++

• Enter in the *S command

• Enter your new password

• Verify your password

• ATO to return online

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☞ If you are not online or in the current session of SuperSecure,

you must identify yourself by entering your current username and password before being able to enter your new password.

Minimum Password Length

You can specify the minimum password length accepted by the modem by the E option from the Security Menu. Its power-on default is 3 characters.

Additional User Options

When a new user is entered into the database you will be

SmartModem Reference Guide

Security & Encryption

prompted for 'Options' after the password has been entered. You may key S or E or both, if you do not want either option key ENTER.

❑ S Specifies that the user is a supervisor and has full

remote access rights to the remote modem.

• If you key **** you will be able to issue almost all AT commands on the remote modem and access the full security database if you have the global security password. (See remote access)

❑ E Your user password does not expire.

• This would be for automated systems that cannot respond to prompts to enter a new password when it expires

Uploading and Downloading the SuperSecure Database

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Encryption

❑ To ensure the integrity of your modem's security database

the sensitive fields are encrypted with the modem's primary key. Your password and DES KEYS are scrambled but will be restored when uploaded into a modem with the same primary key.

❑ You may delete unwanted records and modify the unencrypted

fields, but the encrypted must not be touched.

❑ If you wish to enter a new user, you may do so using the same

format as the other records. The three digit control field at the start of each record should be set to the following values for a new user: 000 Not SuperSecure User, no DES keys specified (use for dialback) 001DES keys specified 003 DES keys specified, Supervisor Status 005 DES keys specified, No password expiry 007 DES keys specified, No password expiry and Supervisor Status

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❑ The record format is:

aaa, "<username>", "<encrypted password>", "<command>", "bbb,ccc,ddd,eee,fff,ggg", "<encrypted key>", "<encrypted> IV", "<encrypted KE>"CR,LF

• aaa is 3 digit control number

• bbb is 3 digit access granted count

• ccc is 3 digit access denied count

• ddd is 3 digit days since password change

• eee is 3 digit reserved

• fff is 3 digit reserved

• ggg is 3 digit reserved

☞ The control number should not be touched on existing users.

Security Database Lock Option

From the Security Menu you may elect to LOCK the security database with the 'L' option. When locked, the user cannot change the #E setting or clear the security database even with the &F. command or power-on reset with the Mode Switch depressed.

The only way to alter the database or #E selection is to enter the Security Menu with the security password and unlock the database with the 'F' (Free) command.

The current state: LOCKED or FREE is displayed below the Security Menu.

☞ Shorting out the NOVRAM battery will erase the database but

will result in the modem being only partially functional. Such modems need to be returned to the factory for re-configuration.

Outdial Disable Option

If modems are to be used only for receiving calls option 'K' can be selected. This does not allow the modem to dial out. If an attempt to do so, users will be informed that a SECURITY LOCKOUT is in place and the call will not be successful.

The outdial feature will be useful for system administrators who

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wish to control the use of modems within remote offices or restrict modems to being used for receiving calls only.

Dial Stored Phone Numbers Only Option

Option 'M' is similar to Option 'K' but restricts the modem to dialling only those numbers listed in the stored phone number fields as set with the &Z command.

The stored numbers must then be dialled using the ATDS=X command where X is the position of the stored number as set with the AT&Z command.

New stored numbers cannot be added by the user once the dial restriction has been enabled.

General Notes on Data Security

❑ By using SuperSecure you now have

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• Ensured that the phone link between two modems is secure

• Ensured that no other user can access either modem when #E2 is enabled

❑ The weak link in the system is now the cable between your

modem and your computer.

• It should be kept visible at all times to prevent wire tapping

• The modem, computer and interconnecting cable should be physically secure to prevent access

❑ With specialised equipment, the data on the lines and the image

on an screen can be read, due to wires and video screens radiating radio frequency signals which can be picked up over a distance. You may need advice on radio frequency screening if this concerns you.

SmartModem Reference Guide

SYNCHRONOUS MODES

This section explains the use of your modem in synchronous modes. A dumb mode or manual mode allows some of the functions of your modem to be accessed via the front panel switches.

Some of the information in this section assumes you have read the Getting Started Section.

Your modem offers two synchronous modes, conforming to the Hayes modem synchronous modes 1 and 2. These modes allow synchronous communication over two-wire PSTN or leased lines when connected to asynchronous/synchronous computers or dedicated synchronous terminals.

Synchronous Operation

Your modem supports two synchronous modes. Mode 1 allows operation with computers which support asynchronous and synchronous communication on a single RS-232 port. Mode 2 allows your modem to be operated with dedicated synchronous terminals.

Synchronous Modes

Although your modem can only operate over a single two-wire connection, it will still perform full-duplex synchronous communication. Half-duplex operation could be simulated by controlling the state of the RTS and CTS signals.

Terminal Speeds

Your synchronous terminal or host should use the clock signals provided by the modem to synchronise transmit and receive data. The clock speed will represent the actual connection speed of the modem.

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Synchronous

Modes

Synchronous Modes

☞ When synchronous mode is selected, your modem cannot

operate in constant speed mode or use the error correction or data compression facilities of the modem. Only variable speed mode is available in synchronous connections (this refers to the modem's terminal speed).

Line Speeds

Your modem supports a number of synchronous line speeds. Your Command Card lists the line speeds available for your modem.

When operating in synchronous mode, your modem should always be configured with a locked, non-auto-ranging B setting (this refers to modem line speed).

For V.34 or V.FC, the B setting only sets the maximum speed. The modem will automatically determine the highest usable speed for the line.

Modes

Synchronous

SmartModem Reference Guide

Synchronous Mode 1

-li

Fai

-li

Fai

Your modem is capable of dialling remote systems in asynchronous mode and then automatically switching to synchronous mode once connection has been made. If the connection is lost, your modem will hang up and return to asynchronous local command state.

The computer required to support synchronous communication with your modem must be capable of switching between synchronous and asynchronous modes with the same RS-232

Synchronous Modes

Asynchronous

Local Command State

❏

ssued

ATO

❏

ATD issued

DTR Lowered (&D1)

Synchronous On

ang Up

Asynchronous

Local Command State

Connection

shed

Establ

ne State

DTR Lowered (&D0, &D2) or Remote

er Lost

Carr

Connect

led

❏

ssued

ATA

❏

Incoming Call

DTR Lowered (&D1)

Synchronous On

ang Up

Synchronous Mode 1 Originate and Answer Modes

Connection

shed

Establ

ne State

DTR Lowered (&D0, &D2) or Remote

er Lost

Carr

Connect

led

Synchronous

Modes

SmartModem Reference Guide

Synchronous Modes

port, as well as controlling the state of the DTR signal under software supervision.

Selecting Synchronous Mode 1

Synchronous mode 1 is selected with the &M1 command.

• Type: AT&M1 <E>

Your modem will enter synchronous mode whenever it successfully connects to a remote modem.

You should also:

• Type: AT&D2 <E>

This allows hang up via your computer’s DTR signal.

☞ Your computer will not be able to hang up the modem if the

DTR Option Switch is in the DOWN position (DTR will always be asserted). DTR must be lowered to make the modem hang up.

To return to asynchronous operation:

• Type: AT&M0 <E>

Modes

Synchronous

Dialling

Your computer must be in asynchronous mode before dialling commences. To begin dialling use the D command. Response codes sent to the computer depend upon the settings of the X, V and Q commands. As soon as a connection can be established, your modem will assert CTS and enter synchronous on-line state. If connection cannot be made, your modem will hang up and return to asynchronous local command state.

Character echo and response codes should not be selected when synchronous communications are used. Use the E0 and Q1 commands to disable character echo and response codes.

As soon as your modem has completed dialling it will examine

SmartModem Reference Guide

Synchronous Modes

the state of the DTR signal. If DTR is asserted your modem will go on line in synchronous mode, otherwise the modem will hang up and return to asynchronous local command state.

☞ Data should only be transmitted once DCD, DTR and CTS

have been asserted. Your computer should not assume that if CTS is asserted then it is safe to begin transmitting data — your modem will keep CTS asserted whenever it is in local command state.

Hanging Up

Your modem will hang up and return to asynchronous mode if carrier is lost for longer than the period defined by S Register 10 or if DTR is lowered after the &D2 command has been issued.

Answering Calls

To automatically answer incoming calls, S Register 0 must be set to a non-zero value (as with asynchronous auto-answering). Once a call has been answered there is no means of returning to asynchronous mode apart from hanging up the modem. This will occur if the carrier is lost for a period in excess of the time defined by S Register 0 or if DTR is lowered after the &D2 command has been issued.

SmartModem Reference Guide

Synchronous

Modes

Synchronous Modes

-li

Fai

-li

Fai

Synchronous Mode 2

Synchronous mode 2 is specifically designed for use with dedicated synchronous terminals. The phone number to be dialled is stored in the modem, the synchronous terminal causing the modem to dial by asserting the DTR signal.

When the terminal asserts the DTR signal (DTR makes an OFF-ON transition), your modem will dial stored phone number zero. The phone number may contain dial modifiers. See the Command Descriptions chapter of this guide for details on the &Z command.

Before connecting your modem to your synchronous terminal, the modem must first be configured using an asynchronous terminal or computer.

The Sample Setups section of this manual details a

Modes

Synchronous

Asynchronous Local

Command State

(Response Codes d

❏

DTR signal asserted

Connection Establ

Synchronous

ne State

DTR Lowered or Remote Carr

ang Up

Synchronous Mode 2 Originate and Answer Modes

sabled)

shed

Connect

DTR Low

er Lost

led

Asynchronous Local

Command State

(Response Codes d

❏

Incoming Call and

gnal asserted

DTR s

Synchronous On

ang Up

sabled)

Connection

shed

Establ

ne State

DTR Lowered or Remote Carr

Connect

DTR Low

er Lost

led

SmartModem Reference Guide

Synchronous Modes

common configuration for synchronous mode 2.

Selecting Synchronous Mode 2

Synchronous mode 2 is selected with the &M2 command.

• Type: AT&M2 <E> Your modem will enter synchronous mode whenever it successfully connects to a remote modem.

You should also:

• Type: AT&D2 <E>

This allows you to dial and hang up.

To return to asynchronous mode:

• Type: AT&M0 <E>

Your modem will remain in asynchronous mode.

Dialling

Dialling will commence as soon as the DTR signal is asserted (an OFF-ON transition occurs). Your modem will not generate response codes when synchronous mode 2 is selected. All call progress is indicated by your modem’s speaker (the M command controls the operation of your modem’s speaker).

As soon as your modem connects to a remote modem it will assert the DSR and DCD signals.

Hanging Up

Your modem will hang up and return to quiet asynchronous mode if the carrier is lost for longer than the period defined by S Register 10 or if DTR is lowered.

Answering Calls

Whenever your modem receives an incoming call it will assert the RI signal. The terminal may accept the call by asserting the DTR signal as soon as the number of rings defined by S Register 0 is reached. The terminal may refuse the call by keeping DTR low eight seconds after the number of rings in S Register 0 is reached.

Your modem will not dial the stored number in response to DTR

SmartModem Reference Guide

Synchronous

Modes

Synchronous Modes

LEASED LINE OPERATIONS

A leased line, or private line, is a telephone line that permanently connects two or more locations. The leased line does not have any switching equipment associated with it.

Leased-line operation with the modem is selected with the &L command.

The &L command informs your modem that communications will occur over leased lines, with no answer tones being generated by the modem. If the modem detects a loss of the remote carrier signal while leased-line operation is selected, it will attempt to re-establish the connection rather than hang up.

If you select leased line operation with the &L1 command, you must issue the ATA command to answer a call, and the ATD command to initiate a call.

If you use &L2 or &L3 to select Auto leased line operation, you do not need to issue the ATA or ATD commands; &L2 selects Originate mode automatically and &L3 selects Answer mode automatically. To dial or answer, raise DTR; to return to local command state, lower DTR.

Modes

Synchronous

☞ You will require a special phone cable (available from your

dealer) to connect your modem to a leased-line socket. The phone cable supplied with your modem is suitable for use with normal, dial-up, voice (PSTN) lines.

Before commencing leased-line communications, it is recommended that a non-auto-ranging B setting be specified.

☞ If error correction is required, select a Reliable mode, not an

Auto-Reliable mode. (See the \N command.)

Auto-ranging and fallback are disabled in leased-line mode. Your modem will only attempt to connect using the communications standard specified by the B command and the

SmartModem Reference Guide

ff-

1) -

terminal speed. Once a connection has been established, if your modem detects a loss of carrier it will continuously attempt to re-establish the connection.

Smart Leased- Line Mode

Leased-line operation is available in both asynchronous and synchronous mode 1.

Asynchronous Local

DTR lowered (&D2)

DTR lowered

Command State

ATD or ATA

ssued

Key Pressed

ATH issued or Carrier Lost - Async only

Synchronous Modes

Sync only

Async only

Attempt to

sh Connection

Establ

Carrier

Lost

On-line State

ATO

ssued -

hook

Asynchronous Local

Command State

Connection

Establ

Escape Sequence or DTR lowered

Async mode

(&D

Synchronous

Modes

Smart Leased-Line Mode (&L1)

Calling and AnsweringUsing &L1

When operating in smart mode (&L1 set), the ATD and ATA commands are used to initiate and answer calls respectively.

☞ Your modem will hang up and return to local command state

if your computer transmits characters while the modem is attempting to establish or re-establish a connection (unless &N0 has been issued).

SmartModem Reference Guide

Synchronous Modes

Auto Leased Line Operation (&L2 or &L3)

You can select Auto leased line operation with the &L2 or &L3 command. In Auto leased line operation you do not need to issue the ATA command to answer a call, or the ATD command to initiate a call. Issue the &L2 command to automatically select Originate mode, or the &L3 command to automatically select Answer mode.

In Auto leased line operation AT commands can only be entered while DTR is low. Irrespective of the &D setting, your modem will remain in idle mode when DTR is low, and will go on-line when DTR is high and the modem’s TALK/DATA switch is set to DATA. If DTR is lowered (or the TALK/DATA switch is set to TALK) when your modem is on-line, it will hang up and return to idle mode. If power is lost, your modem will enter online state when DTR is restored.

☞ Your communications software must be capable of altering

the state of the DTR signal to work successfully with the &L2 and &L3 commands. If your modem has a TALK/DATA switch, it must be set to DATA.

Modes

Synchronous

Hanging Up

There are four ways of hanging up your modem when leased-line mode is selected.

❏ If your modem is attempting to establish or re-establish a

connection, sending characters to it will cause it to hang up (unless &N0 has been issued).

❏ If synchronous mode is selected, lowering the DTR signal

will cause your modem to immediately hang up.

❏ If asynchronous mode is selected, issuing the ATH command

will cause the modem to hang up.

❏ If asynchronous mode is selected (&L2 or &L3), lowering

DTR will cause the modem to hang up.

❏ Switch the TALK/DATA switch to TALK.

SmartModem Reference Guide

☞ XON/XOFF flow control should not be selected for leased-

line connections. Your modem will prematurely hang up if your computer sends an XON/XOFF character while the modem is attempting to re-establish a connection.

Improving the Reliability of Leased-Line Connections

If you are experiencing data errors over leased lines, issue the %L command to lower the transmit level of your modem.

You may need to experiment with the levels, but start between %L15 and %L19.

The transmit level should be changed on both modems.

Synchronous Modes

SmartModem Reference Guide

Synchronous

Modes

Dumb Mode

DUMB MODE OPERATION

Your modem has two methods of operating with your computer. The commonly used method is “smart mode”, where the computer issues “AT” commands to the modem to make it dial and hang up

For computers which do not offer an asynchronous port or cannot communicate synchronously using V.25bis commands, dumb mode permits manual control of your modem.

Selecting Dumb Mode on Desktop Modems

To select Dumb mode:

• Place front panel Option switch 4 in the Down position

To select Smart mode:

• Place front panel Option switch 4 in the Up position

Dumb Mode

The Option Switches and Mode and Talk/Data buttons

Some modems also have rear panel Option switches — check the rear panel of your modem.

HINT:

To restore the factory settings of your modem, switch it on holding the Mode button in, until the modem “beeps” twice.

SmartModem Reference Guide

Dumb Mode

Selecting Dumb Mode on ProRack Modems

To select Dumb mode on a ProRack modem:

• Place front panel Option switch 6 in the On (or Left) position

To select Smart mode:

• Place front panel Option switch 6 in the Off (or Right) position

ProRack Modem Option Switches

Setting Up your Modem

In most instances, your modem will need to be configured prior to entering Dumb mode. All configuration of your modem is performed using the AT commands.

For example, if you wish to have your modem dial a stored telephone number when the computer asserts (or “raises”) the DTR signal, you must first store the telephone number in the modem and select stored number dialling operation, using the AT commands.

SmartModem Reference Guide

Dumb Mode

Selecting Communications Speeds on Desktop Modems

If you are dialling in Dumb mode, the communication speed it uses is dependant upon the setting of the front panel Mode LEDs.

To change the speed at which your modem connects after dialling:

• Place front panel Option switches 3 and 4 in the Down position (disable auto-answering, select Dumb mode)

• Press the Mode button (located next to the front panel Option switches) until the correct speed is indicated on the front panel Mode LEDs

☞ Your modem cannot dial if auto-answer is enabled.

Refer to the table printed in your modem Installation Guide - it shows the meaning of each combination of the Mode LEDs.

Dumb Mode

To change the speed at which your modem connects after answering an incoming call:

• Place front panel Option switch 4 in the Up position (select Smart mode)

• Connect your modem to a personal computer — refer to the modem Installation Guide for details

• Run a communications program (such as Cooee or MicroPhone) and enter “local mode” or “terminal mode”

• Type: ATBx&W <E> where “x” is a valid setting of the B command. For example, ATB13&W selects V.32 (9600 bps) mode.

The B command is used to set the communications standard used by your modem.

SmartModem Reference Guide

Selecting Communications Speeds on ProRack Modems

If you are dialling in Dumb mode, the communication speed it uses is dependant upon the setting of the front panel Mode LEDs.

To change the speed at which your modem connects after dialling

• Place front panel Option switches 5 and 6 in the On (or Left)

position to select Dumb mode and disable auto-answer

• Press the Mode button until the correct speed is indicated on

the front panel Mode LEDs

☞ Your modem cannot dial if auto-answer, verify this is enabled.

Refer to the table printed in your modem Installation Guide — it shows the meaning of each combination of the Mode LEDs.

Dumb Mode

To change the speed at which your modem connects after answering an incoming call:

• Place front panel Option switch 6 in the Off (or Right)

position to select Smart mode

• Connect your modem to a personal computer — refer to the

modem Installation Guide for details

• Run a communications program (such as Cooee or

MicroPhone) and enter “local mode” or “terminal mode”

• Type: ATBx&W <E>

where “x” is a valid setting of the B command. For example, ATB13&W selects V.32 (9600 bps) mode.

The B command is used to set the communications standard used by your modem.

SmartModem Reference Guide

Dumb Mode

Hints for Unix Computers and Multiplexers

Many Unix computers and multiplexers which offer synchronous communications ports cannot cope with the response messages generated by the modem. For this reason, you may wish to switch off response messages before you connect your modem to the Unix computer or multiplexer.

• Place front panel Option switch 4 in the Up position to select

Smart mode For ProRack modems, place switch 6 in the Off (or Left)

position.

• Connect your modem to a personal computer, a Unix computer

or a serial server — refer to the modem Installation Guide for details

• Run a communications program (such as Cooee or MicroPhone

for Windows, or TIP or CU for Unix) and enter “local mode” or “terminal mode”

• Type: ATE0Q1&N0&W <E>

• Exit the communications program

Dialling in Dumb Mode

Dumb Mode

This command switches off response messages and character echo, causes the modem to ignore characters sent to it from the host while dialling or answering, and saves the changes in the modem.

There are three ways of dialling in dumb mode:

❏ Use a telephone handset connected to the modem. ❏ Store a telephone number in the modem and then have the

computer raise the DTR signal.

❏ Store a telephone number in the modem and then press the

Talk/Data switch.

☞ ProRack modems can dial only by raising the DTR signal to

dial a stored telephone number.

SmartModem Reference Guide

Dialling with a Telephone Handset

Manual dialling requires a telephone handset to be connected to the same phone line as your modem. Use a telephone cable with a double adaptor socket to connect your modem and telephone to the same phone line

This form of dumb-mode dialling is not supported by ProRack modems.

• Set up your modem in “smart mode”, using the AT commands.

• Place front panel Option switch 4 in the Down position (select Dumb mode)

• Place front panel Option switch 6 in the Down position (select Originate mode)

• Place front panel Option switch 3 in the Down position (disable auto-answering)

☞ Your modem cannot dial if auto-answer is enabled.

• If necessary, use the Mode button to select the required communication speed

Dumb Mode

The connection speed of the modem is indicated by the Mode LEDs. Refer to the table printed in your modem Installation Guide - it shows the meaning of each combination of Mode LEDs.

• Press the Talk/Data button to Talk (this button is located next to the front panel Option switches)

• Using the telephone handset, dial the number

• As soon as the other modem answers your call, press the Talk/ Data button to Data

If the AT&D2 command has been issued prior to entering Dumb mode, your computer must raise the DTR signal before you press the Talk/Data button.

• Place the handset on-hook The OH and CD LEDs glow when the modem connects. To hang up:

• Press the Talk/Data button to Talk

SmartModem Reference Guide

Dumb Mode

Using the Talk /Data Button to Dial

You may commence dialling by pressing the Talk/Data button, located next to the front panel Option switches. By dialling in this manner, you do not need to use a telephone handset.

This form of dumb-mode dialling is not supported by ProRack modems.

• Place front panel Option switch 4 in the Up position (select Smart mode)

• Connect your modem to a personal computer — refer to the modem Installation Guide for details

• Run a communications program (such as Cooee or MicroPhone) and enter “local mode” or “terminal mode”

• Type: AT&Z0=phoneno <E>

Where “phoneno” is the telephone number you want your modem to dial. This command stores the number as stored telephone number zero.

☞ If you are using your modem over leased lines, do not store a

phone number.

Dumb Mode

• Type: AT&D2&M4 <E>

or:

Type: AT&D2E0Q1&M2 <E>

Issue the &M4 command if you wish to use asynchronous communications; issue &M2 if you wish to use synchronous communications.

• Type: AT&W <E> The modem set up is saved.

• Place front panel Option switch 4 in the Down position (select Dumb mode)

• Place front panel Option switch 6 in the Down position (select Originate mode)

• Place front panel Option switch 3 in the Down position (disable auto-answering)

☞ Your modem cannot dial if auto-answer is enabled.

SmartModem Reference Guide

Dumb Mode

• If necessary, use the Mode button to select the required communication speed

The connection speed of the modem is indicated by the Mode LEDs. Refer to the table printed in your modem Installation Guide; it shows the meaning of each combination of Mode LEDs.

• Raise the DTR signal on your computer If your modem has a TR front panel LED, it glows when DTR is raised.

• Press the Talk/Data button to Data The Talk/Data button must be changed from Talk to Data to cause the modem to dial.

Your modem dials stored telephone number zero. The OH and CD LEDs glow when the modem connects.

To hang up:

• Have your computer lower the DTR signal or press the Talk/ Data switch to Talk

Using DTR to Dial

You may commence dialling by having your computer raise its DTR signal.

• Place front panel Option switch 4 in the Up position (select Smart mode) For ProRack modems, place switch 6 in the Off (or Right) position.

• Connect your modem to a personal computer — refer to the modem Installation Guide for details

• Run a communications program (such as Cooee or MicroPhone) and enter “local mode” or “terminal mode”

• Type: AT&Z0=phoneno <E>

Where “phoneno” is the telephone number you want your modem to dial. This stores the number as stored telephone number zero.

☞ If you are using your modem over leased lines, do not store a

phone number.

SmartModem Reference Guide

Dumb Mode

• Type: AT&D2&M4 <E>

or:

Type: AT&D2&M2 <E>

Issue the &M4 command if you wish to use asynchronous communications; issue &M2 if you wish to use synchronous communications.

• Type: AT&Wn <E>

The modem set up is saved to profile n=0-3

• Place front panel Option switch 4 in the Down position (select Dumb mode) For ProRack modems, place Option switch 6 in the On (or Left) position.

• Place front panel Option switch 6 in the Down position (select Originate mode) For ProRack modems, place Option switch 8 in the On (or Left) position.

• If necessary, use the Mode button to select the required communication speed

Dumb Mode

The connection speed of the modem is indicated by the Mode LEDs. Refer to the table printed in your modem Installation Guide; it shows the meaning of each combination of Mode LEDs.

• Press the Talk/Data button to Data (this button is located next to the front panel Option switches) ProRack modems do not have a Talk/Data button; they are permanently set to “Data”.

• Raise the DTR signal on your computer

DTR must change from “low” to “high” to commence dialling. Your modem dials the stored telephone number zero. The OH and CD LEDs glow when the modem connects.

To hang up:

• Have your computer lower the DTR signal, or press the

Talk/Data button to Talk

SmartModem Reference Guide

Answering Calls in Dumb Mode

Your modem is able to answer incoming calls, automatically or by manual intervention.

Automatic Answering

Your modem is able to auto-answer incoming calls in Dumb mode. You do not need a telephone handset to have your modem answer incoming calls.

• Place front panel Option switch 4 in the Up position (select Smart mode) For ProRack modems, place Option switch 6 in the Off (or Right) position.

• Connect your modem to a personal computer — refer to the modem Installation Guide for details

• Run a communications program (such as Cooee or MicroPhone) and enter “local mode” or “terminal mode”

• Type: ATBx <E> where “x” is a valid setting of the B command. The B command is used to set the communications standard used by your modem.

• Type: AT&D2&M0 <E>

or:

Type: AT&D2E0Q1&M1 <E>

Dumb Mode

Issue the &M0 command if you wish to use asynchronous communications; issue &M1 if you wish to use synchronous communications.

• Type: AT&W <E> The modem set up is saved.

• Place front panel Option switch 4 in the Down position (select Dumb mode) For ProRack modems, place Option switch 6 in the On (or Left) position.

• Place front panel Option switch 6 in the Up position (select Answer mode)

SmartModem Reference Guide

Dumb Mode

For ProRack modems, place Option switch 8 in the Off (or Right) position.

• Place front panel Option switch 3 in the Up position (allow auto-answering of incoming calls) For ProRack modems, place Option switch 5 in the Off (or Right) position.

If the &D2 command has been issued to the modem, DTR must be raised by your computer.

• Press the Talk/Data button (located next to the front panel Option switches) to Data ProRack modems do not have a Talk/Data switch; they are permanently set to “Data”.

Your modem answers incoming calls after the number of rings specified in S Register 0.

Manual Answering

For reasons of data security, it may be desirable to verbally identify a caller before allowing connection to your computer. A telephone handset must be connected to the same telephone line as your modem to permit manual answering — refer to your modem Installation Guide for details of connecting a telephone handset.

Dumb Mode

This form of dumb-mode answering is not supported by ProRack modems.

• Place front panel Option switch 4 in the Up position (select Smart mode)

• Connect your modem to a personal computer — refer to the modem Installation Guide for details

• Run a communications program (such as Cooee or MicroPhone) and enter “local mode” or “terminal mode”

• Type: ATBx <E> where “x” is a valid setting of the B command. The B command is used to set the communications standard used by your modem.

SmartModem Reference Guide

Dumb Mode

• Type: AT&D2&M0 <E>

or:

Type: AT&D2&M1 <E>

Issue the &M0 command if you wish to use asynchronous communications; issue &M1 if you wish to use synchronous communications.

• Type: AT&W <E>

The modem set up is saved.

• Place front panel Option switch 4 in the Down position (select Dumb mode)

• Place front panel Option switch 6 in the Up position (select Answer mode)

• Place front panel Option switch 3 in the Down position (stop auto-answering of incoming calls)

If the &D2 command has been issued to your modem, your computer must raise the DTR signal

• Press the Talk/Data button to Talk (this button is located next to the front panel Option switches)

• When the telephone handset rings, pick it up and establish the caller identity

The person calling you must perform a manual dial (that is, he/ she must dial using a telephone handset).

• When you are ready to allow access to your computer, press the Talk/Data button to Data

• Place the handset on-hook

At the same time, the caller must make his/her modem enter “data mode” and place his/her handset on-hook. (Refer to Dialling with a Telephone Handset section)

The OH and CD LEDs glow when the modems connect.

SmartModem Reference Guide

Dumb Mode

The Option Switches

The Option switches allow you to control the operation of your modem in Dumb mode, as well as providing additional features in Smart mode.

This section explains the use of Option switches for desktop modems (with or without rear panel Option switches) and ProRack modems.

Modems with Rear Panel Option Switches

If your modem has rear panel Option switches, these functions are available:

Description Switch

DSR acts normally Sw 1 - Up DSR mimics DTR Sw 1 - Down DTR controlled by the computer Sw 2 - Up DTR is assumed to be asserted Sw 2 - Down DCD is asserted after a connection Sw 4 - Up DCD is always asserted Sw 4 - Down

Dumb Mode

The operation of the front panel option switches is identical to desktop modems without rear panel option switches. Refer to Modems without Rear Panel Option Switches section.

NOTE:

For users of modems with front and rear panel switches

• Rear panel Option switches always take precedence over front panel Option switches.

For users of modems with front panel Option switches only

• Front panel Option switches 1 and 2 always take precedence over software setting of behaviour of DTR and DSR. When AT%F is set to 1 (when AT%F is set to 0, behaviour of DTR and DSR is controlled by AT commands if applicable).

SmartModem Reference Guide

Modems without Rear Panel Option Switches

Switches 1 and 2 are used to select AT command mode or V.25bis command mode, or control the state of the DTR and DSR signals.

Description AT%F Switch 1 Switch 2

AT command mode %F0 Up Up V.25bis asynchronous %F0 Up Down V.25bis synchronous (HDLC framing) %F0 Down Up V.25bis sync (BSC character framing) %F0 Down Down DTR controlled by computer %F1 Up n/a DTR assumed to be asserted (raised) %F1 Down n/a DSR acts normally %F1 n/a Up DSR mimics DTR %F1 n/a Down

☞ n/a = not applicable

Switches 3 - 6 allow you to set up Dumb mode operation, as well as manually selecting loopback tests in Smart mode.

Description AT#F Switch Switch

Smart mode n/a 4 - Up n/a Dumb mode n/a 4 - Down n/a Loopback Test Pattern Off #F1 3 - Up 4 - Up Loopback Test Pattern On #F1 3 - Down 4 - Up Analog Loopback Off #F1 5 - Up 4 - Up Analog Loopback On #F1 5 - Down 4 - Up Remote Digital Loopback Off #F1 6 - Up 4 - Up Remote Digital Loopback On #F1 6 - Down 4 - Up Auto-answer enabled n/a 3 - Up 4 - Down Auto-answer disabled n/a 3 - Down 4 - Down Asynchronous operation n/a 5 - Up 4 - Down Synchronous operation n/a 5 - Down 4 - Down Answer mode n/a 6 - Up 4 - Down Originate mode n/a 6 - Down 4 - Down

Dumb Mode

☞ n/a = not applicable

SmartModem Reference Guide

Dumb Mode

ProRack Modems

ProRack modem offer the following front panel Option switches:

Description Switch

Auto-answer enabled 5 - Off (Right) Auto-answer disabled 5 - On (Left) Smart mode 6 - Off (Right) Dumb mode 6 - On (Left) Asynchronous operation 7 - Off (Right) Synchronous operation 7 - On (Left) Answer mode 8 - Off (Right) Originate mode 8 - On (Left)

V.25bis mode is selected with Option switches 3 and 4:

Description Switch 3 Switch 4

AT command mode Off (Right) n/a V.25bis synchronous (HDLC framing) On (Left) Off(Right) V.25bis sync (BSC character framing) On (Left) On (Left)

Dumb Mode

SmartModem Reference Guide

CCITT V.25bis OPERATIONS

V.25bis is a modem command set specified by the CCITT. Like the AT command set, it allows you to control your modem. However, V.25bis commands may be issued to the modem in asynchronous or synchronous mode (AT commands may only be issued when the modem is operating in asynchronous mode). This means V.25bis is suitable for mainframe and minicomputers which only support synchronous communications ports. The implementation of V.25bis supported by your modem is based upon the 1988 revision of the V.25bis specification, however not all aspects of the V.25bis specification have been implemented.

☞ V.25bis operation is supported in both smart and dumb

modes.

Selecting V.25bis Operation

V.25bis Operations

To select V.25bis mode, issue the appropriate #M command. Three V.25bis modes are supported by your modem:

❏ Asynchronous V.25bis. The modem operates in asynchronous

mode using V.25bis command rather than AT commands. Issue the AT#M1 command to select this mode.

❏ Synchronous V.25bis with HDLC framing. The modem

communicates and accepts V.25bis commands in synchronous mode with HDLC framing. Issue the AT#M2 command to select this mode.

❏ Synchronous V.25bis/BSC mode. The modem communicates

and accepts V.25bis commands in synchronous mode with character framing (BSC mode). Issue the AT#M3 command to select this mode.

SmartModem Reference Guide

Operations

V.25bis

V.25bis Operations

The &W and Z commands must be issued after the #M command in order for V.25bis command mode to be selected. Alternately, issue the &W command after the #M command and switch the modem off and on or lower DTR (after an &D3 command has been issued).

☞ When you reset the modem (for example, you issue the &F

If your modem has Option switches to select V.25bis operation, the setting of the Option switches always take precedence over the #M command.

The %R2 option will be required for most V.25bis setups. This setting ensures that the CTS signal is only asserted when the modem is ready to accept a new command (in command mode).

command or issue the RST command or switch the modem off and on), you must issue an ATZ command to select V.25bis command mode; your modem always resets and powers-up in AT command mode, regardless of the setting of the #M command.

V.25bis

Operations

Overridden Settings

Almost all AT commands and S Registers stored before entering V.25bis mode will have effect except for the following commands.

AT Command V.25bis Operation

&D Will act as if &D2 is selected S0 Will act as if S0=1

These override settings are not stored in your modem’s nonvolatile memory; they are active only while V.25bis command mode is active. If you issue the &V command to view the modem’s configuration the original settings will be displayed.

SmartModem Reference Guide

Octek SMART MoDeM, VoiceMaster, Socket Rocket Reference Guide

Specifications and Main Features

Frequently Asked Questions

User Manual