ZyXEL Communications 288S User Manual

Omni 288S

User’s Manual

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3

Foreword

Limited Warranty

ZyXEL warrants to the original end user (purchaser) that this product is free from any
defects in materials or workmanship for a period of up to two (2) years from the date of
purchase. During the warranty period, and upon proof of purchase, should the product
have indications of failure due to faulty workmanship and/or materials, ZyXEL will, at its
option, repair or replace the defective products or components without charge for either
parts or labor, and to whatever extent it shall deem necessary to restore the product or
components to proper operating condition. Any replacement will consist of a new or
remanufactured functionally equivalent product of equal value, and will be solely at the
option of ZyXEL. This warranty shall not apply if the product is modified, misused,
tampered with, damaged by an act of God, or subjected to abnormal working conditions.

Note: Repair or replacement, as provided under this warranty, is the exclusive remedy of
the purchaser. This warranty is in lieu of all other warranties, express or implied, including
any implied warranty of merchantability or fitness for a particular use or purpose. ZyXEL
shall in no event be held liable for indirect or consequential damages of any kind or
character to the purchaser.

To obtain the services of this warranty, please contact ZyXEL’s Service Center, refer to
the separate Warranty Card for your Return Material Authorization number (RMA).
Products must be returned Postage Prepaid. It is recommended that the unit be insured
when shipped. Any returned products without proof of purchase or those with an out­dated warranty will be repaired or replaced (at the option of ZyXEL) and the customer
will be billed for parts and labor. All repaired or replaced products will be shipped by
ZyXEL to the corresponding return address, Postage Paid (USA and territories only). If
the customer desires some other return destination beyond U.S. borders, the customer
shall bear the cost of the return shipment. This warranty gives you specific legal rights,
and you may also have other rights which vary from state to state.

Copyright  1996 by ZyXEL

The contents of this book may not be reproduced (in any part or as a whole) or
transmitted in any form or by any means without the written permission of the publisher.

Published by ZyXEL Communications, Inc. All rights reserved.
Omni 288S User’s Manual, Rev no. 1.01

Liability Notice

ZyXEL does not assume any liability arising out of the application or use of any products,
or software described herein. Neither does it convey any license under its patent rights
nor the patents rights of others. ZyXEL further reserves the right to make changes in any
products described herein without notice. This document is subject to change without
notice.

Acknowledgements

The trademarks and brand names mentioned in this manual are used for plain
informational purposes. Trademarks and brand names are the property of their respective
owners.

i

Foreword

FCC Part 15 Information

This device complies with Part 15 of FCC rules. Operation is subject to the following two
conditions:

1. This device may not cause harmful interference.

2. This device must accept any interference received, including interference that may
cause undesired operations.

This equipment has been tested and found to comply with the limits for a CLASS B
digital device pursuant to Part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference in a residential installation. This
equipment generates, uses, and can radiate radio frequency energy, and if not installed
and used in accordance with the instructions, may cause harmful interference to radio
communications. However, there is no guarantee that interference will not occur in a
particular installation.

If this equipment does cause harmful interference to radio/television reception, which can
be determined by turning the equipment off and on, the user is encouraged to try to
correct the interference by one or more of the following measures:

Reorient or relocate the receiving antenna.

•

Increase the separation between the equipment and the receiver.

•

Connect the equipment into an outlet on a circuit different from that to which the

•

receiver is connected.
Consult the dealer or an experienced radio/TV technician for help.

•

Changes or modifications not expressly approved by the party responsible for compliance
could void the user’s authority to operate the equipment. Shielded RS-232 cables are
required to be used to ensure compliance with FCC Part 15, and it is the responsibility of
the user to provide and use shielded RS-232 cables.

FCC Requirements

This equipment complies with Part 68 of the FCC Rules. On the base unit of this
equipment is a label that contains, among other information, the FCC Registration
Number and the Ringer Equivalence Number (REN) for this equipment.

IF REQUESTED, THIS INFORMATION MUST BE GIVEN TO THE TELEPHONE
COMPANY.

The REN is useful to determine the quantity of the devices you may connect to your
telephone line and still have all of those devices ring when your telephone number is
called. In most, but not all areas, the sum of the RENs of all devices connected to one
line should not exceed five (5.0). To be certain of the number of devices you may
connect to your line, as determined by the total RENs, you should contact your local
telephone company to determine the maximum REN for your calling area.

If your equipment causes harm to the telephone network, the telephone company may
discontinue your service temporarily. If possible, they will notify you in advance. But if

ii

Foreword

advance notice isn’t practical, you will be notified as soon as possible. You will be
informed of your right to file a complaint with the FCC.

Your telephone company may make changes in its facilities, equipment, operations, or
procedures that could affect the proper functioning of your equipment. If they do, you
will be notified in advance to give you an opportunity to maintain uninterrupted telephone
service.

If you experience trouble with this telephone equipment, please contact the Address and
Phone number listed in the warranty card for information on obtaining service or repairs.

The telephone company may ask that you disconnect this equipment from the network
until the problem has been corrected or until you are sure the equipment is not
malfunctioning.

The user is not authorized to repair or modify the equipment beyond uploading firmware
into the flash EPROM.

This equipment may not be used on coin service provided by the telephone company.
Connection to party lines is subject to state tariffs.

Information for Canadian Users

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

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

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

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

Caution:

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

.

iii

Foreword

The Load Number (LN) assigned to each terminal device denotes the percentage
of the total load to be connected to the telephone loop used by the device without
overloading. The termination on a loop may consist of any combination of
devices, subject only to the requirement that the total of the Load Numbers of all
the devices not exceed 100. The load number for the Omni 288S is 10.

This apparatus does not exceed the class B limits for radio noise emissions from digital
apparatus set out in the radio interference regulations of Industry Canada.

Telephone Company Requirements

It is not necessary to notify your telephone company before installing the modem, but
your telephone company may request the following information:

Telephone number to which the modem is connected.

•

Manufacturer and Model Number.

•

ZyXEL Communications Corporation
Omni 288S
FCC Part 68 Approval Number and REN#.

•

1ROTAI-22730-PT-E
REN# 0.3B

You will find also this information on a sticker on the bottom of the modems case.
The modem is connected to a public switched line using a USOC (Universal Service

Order Code) RJ11C modular jack.

iv

Table of Contents

Foreword........................................................................... i

Limited Warranty............................................................................................. i

Copyright 1996 by ZyXEL................................................................................. i

FCC Part 15 Information................................................................................. ii

FCC Requirements.......................................................................................... ii

Information for Canadian Users......................................................................iii

Telephone Company Requirements ...................................................................iv

Chapter 1 - Introduction................................................1-1

How to Use this Manual.................................................................................1-1

Unpacking Your Modem.................................................................................1-2

Becoming a Registered Owner....................................................................... 1-3

Omni 288S Modem Features..........................................................................1-3

Chapter 2 - Installation..................................................2-1

Required Steps for Omni 288S Installation....................................................2-1

Optional Steps for Omni 288S Installation..................................................... 2-2

Driver and Software Installation....................................................................2-3

Windows 95 Driver Installation......................................................................2-3

Windows 95 Dial-up Networking....................................................................2-5

Setup for DOS Fax/Modem Software...............................................................2-9

Chapter 3 - Basic Modem Operation.............................3-1

Understanding AT Commands........................................................................3-1

Using the Windows 95 Hyper Terminal Program............................................. 3-1

Dialing and Answering Techniques................................................................3-2

Dialing using the ATD Command................................................................... 3-2

Auto-Answer and Hook Controls.....................................................................3-3

Making Your First Connection....................................................................... 3-3

Quick Tips when issuing AT Commands........................................................3-4

Modem Result Codes .....................................................................................3-5

Viewing S Register Values.............................................................................3-5

Changing S Register Values........................................................................... 3-6

Non-Volatile Memory....................................................................................3-6

Storing Phone Numbers.................................................................................3-6

Dialing Stored Phone Numbers......................................................................3-6

Saving Settings and User Profiles...................................................................3-7

Helpful Hints for PC Computers ....................................................................3-7

Default Modem Settings for PC’s....................................................................3-7

ZyXEL Serial/Parallel I/O Card .....................................................................3-8

Helpful Hints for Mac Computers.................................................................. 3-8

Special AT Command Settings for Mac...........................................................3-8

Mac Serial Port.............................................................................................3-8

Mac Software Tips.........................................................................................3-8

Helpful Hints for UNIX-Based Computers.....................................................3-9

Serial Cable..................................................................................................3-9

Basic Modem Settings for UNIX.....................................................................3-9

Unix Software Tips........................................................................................3-9

Chapter 4 - Advanced Data Communications...............4-1

Front Panel LEDs...........................................................................................4-1

DTE Interface................................................................................................. 4-2

Synchronous and Asynchronous Communications............................................4-2

UART...........................................................................................................4-2

Serial Port....................................................................................................4-2

RS-232C or EIA-232D/E................................................................................4-3

Serial RS-232C Cable.................................................................................... 4-3

Communication Protocols and Speeds ...........................................................4-3

Universal Protocol Compatibility................................................................... 4-4

Choosing the Modem Link Options.................................................................4-4

Setting the DTE to DCE Rate.........................................................................4-5

Error Control..................................................................................................4-5

Data Compression..........................................................................................4-6

Hardware or Software Flow Control.............................................................4-7

Chapter 5 - Synchronous Mode Operation...................5-1

V.25bis Command Set....................................................................................5-1

Clock Options ................................................................................................5-2

RTS Options...................................................................................................5-2

Command State Options................................................................................. 5-2

Dialing from Synchronous Mode.................................................................... 5-3

Answering from Synchronous Mode ..............................................................5-3

Chapter 6 - Leased Line Operation ...............................6-1

Connecting to a 2-Wire Leased Line.............................................................. 6-1

Leased Line Handshaking............................................................................... 6-1

Terminating a Leased Line Connection ..........................................................6-2

Chapter 7 - Cellular Mode Operation.............................7-1

Cellular Phone Systems.................................................................................. 7-1

Cellular Impairments...................................................................................... 7-1

Cellular Modems and ZyCellular Technology................................................7-2

ZyCellular Modes..........................................................................................7-2

Cellular Mode Usage.....................................................................................7-3

Cellular Modem Installation Examples.......................................................... 7-3

Office Installation .........................................................................................7-6

Chapter 8 - Special Functions.......................................8-1

Security Functions..........................................................................................8-1

Levels of Security..........................................................................................8-1

User Passwords.............................................................................................8-1

Remote Configuration.....................................................................................8-2

Caller Number Delivery (Caller ID).............................................................. 8-4

Distinctive Ring .............................................................................................8-6

Extended Distinctive Ring (EDR).................................................................. 8-7

Setting Up EDR.............................................................................................8-8

EDR Application Example .............................................................................8-9

Chapter 9 - Fax Operation .............................................9-1

Fax Basics...................................................................................................... 9-1

Fax Branding................................................................................................9-1

Modem as Fax Machine .................................................................................9-1

ITU-T T.30 Fax Protocol ...............................................................................9-2

Fax Command sets..........................................................................................9-2

Class 1 Command Set....................................................................................9-2

Class 2 Command Set....................................................................................9-4

Class 2.0 Command Set .................................................................................9-8

Extended Fax AT Command Set....................................................................9-13

Flow Control............................................................................................... 9-16

Fax Reception from a BBS........................................................................... 9-16

Chapter 10 - Voice Mode Operation............................10-1

Voice Data Compression.............................................................................. 10-1

Automatic Detection of Voice, Data, Fax.....................................................10-2

Voice Input/Output Devices .........................................................................10-2

Microphone and Speaker Jacks .................................................................... 10-2

Voice Input/Output Device Selection.............................................................10-2

Voice Mode Application Examples .............................................................10-3

Recording a greeting message......................................................................10-3

Playing a voice file through the internal speaker...........................................10-3

Plaing a voice file through the phone line.....................................................10-4

Omni 288S as a Voice answering machine....................................................10-4

Omni 288S as a Fax answering machine.......................................................10-4

Omni 288S as a Data answering machine.....................................................10-5

Voice States and Operation Modes.............................................................. 10-6

Voice Command State..................................................................................10-6

Voice Data States........................................................................................ 10-7

Events and Actions with Shielded Code ......................................................10-8

Event Detection and Reporting.....................................................................10-8

Action Commands in Voice Data State.......................................................... 10-9

Voice AT Commands................................................................................. 10-10

AT Command Syntax..................................................................................10-11

Supported Commands in Voice Mode Operation..........................................10-12

Voice Mode Action Commands................................................................... 10-14

Voice Mode Configuration Commands........................................................10-16

Chapter 11 - AT Command Set Summaries.................11-1

Basic A T C o m mand Set...............................................................................11-1

Description of ATI2 Output:......................................................................... 11-3

Extended AT& Command Set.......................................................................11-4

Extended AT* Command Set........................................................................ 11-7

Chapter 12 - Status Registers & Result Codes ...........12-1

S-Register Descriptions............................................................................... 12-1

Basic S-Registers "ATSn=x".........................................................................12-1

Extended S-Registers "ATSn=x"....................................................................12-1

Result Code Options ..................................................................................12-10

"ATXn" Result Code Option Table..............................................................12-10

Result Code Field Descriptions..................................................................12-11

Connect Strings for Error Corrected Connections........................................12-11

Chapter 13 - Diagnostics & Troubleshooting............. 13-1

Diagnostics................................................................................................... 13-1

Power-On Self Test......................................................................................13-1

Resetting The Modem .................................................................................. 13-2

Loopback Tests............................................................................................ 13-2

Indicator Lights .......................................................................................... 13-3

Trouble Shooting.......................................................................................... 13-4

Command Echo Problems............................................................................13-5

Appendix A - Upgrading Your Modem.........................A-1

Appendix B - Contacting ZyXEL ..................................B-1

ZyXEL Phone Numbers..................................................................................B-1

Online Access................................................................................................B-2

Internet........................................................................................................ B-2

CompuServe................................................................................................. B-2

Appendix C - Connector Pinouts.................................C-1

Phone Jack Pinouts.........................................................................................C-1

PC Serial Port Pinouts....................................................................................C-1

Macintosh Serial Port Pinouts........................................................................C-2

Glossary........................................................................D-1

Chapter 1 - Introduction

Chapter 1 - Introduction

Congratulations on the purchase of your Omni 288S modem - one of ZyXEL's
premier high-performance products. The Omni 288S is world renown for its
ability to maintain ultra high speeds and clear, quality connections while
communicating around the globe.

How to Use this Manual

The chapters and appendices in this complete User’sManual provide instructions
and operation tips to get your modem functioning quickly and effectively. The
following is a summary of what information you will find in each chapter of this
Manual:

Chapter 2: Installation

Instructions for the installation of your Omni 288S.

Chapter 3: Basic Modem Operation

Overview of basic modem related functions and helpful hints to get you started.

Chapter 4: Advanced Data Communications

Detailed information on protocols and standards supported by the Omni 288S.

Chapter 5: Synchronous Mode Operation

Information on Asynchronous and Synchronous communications.

Chapter 6: Leased Line Operation

Describes the Omni 288S and leased line operations.

Chapter 7: Cellular Mode Operation

Instructions on how to utilize the cellular features of the Omni 288S.

Chapter 8: Special Functions

Instructions on how to use the special features of the Omni 288S.

Chapter 9: Fax Operation

Instructions on how to use the fax features of the Omni 288S.

Chap 10: Voice Mode Operation

How to take advantage of the voice features of the Omni 288S.

Chap 11: AT Command Set Summaries

Summary of Basic and Extended AT Commands supported by the Omni 288S.

Chap 12: Status Registers & Result Codes

Viewing and setting S-Registers and Result Codes.

1-1

Chapter 1 - Introduction

Chap 13: Diagnostics & Troubleshooting

Tips for resolving modem problems and for using the Omni 288S’s diagnostic
capabilities.

Appendix A: Upgrading Your Modem

Describes the process for upgrading the Omni 288S with flash EPROM.

Appendix B: Contact ZyXEL

How to contact ZyXEL for product support and configuration questions.

Appendix C: Connector Pinouts

Lists the pinouts of the various connectors on the Omni 288S.
If you do not find information on a specific topic, or if you would like more

information about a topic covered in your Omni 288S User's Manual, please call
ZyXEL Technical Support at 714-693-0808. Other means of contacting ZyXEL
are listed in Appendix B.

Unpacking Your Modem

Enclosed Equipment

Before you proceed further, please check all items you received with your modem
againgt this list to make sure nothing is missing. The complete package should
include:

 one (1) Omni 288S universal modem
 one (1) AC power adapter (external model)
 one (1) RJ11 modular telephone cable
 one (1) Omni 288S User’s Manual
 one (1) ZyXEL modem driver diskette with Windows 95 INF file
 one (1) Data/Fax software for DOS and Windows environments
 one (1) warranty/registration card

Contact your dealer or the store where you bought the modem if anything is
missing. Check the modem for shipping damages. If you find any damage, contact
the shipping agency immediately.

Retain shipping and cushioning materials for future storage or shipping needs.
Please direct any additional questions about damaged or missing materials to your

dealer or distributor, or to the factory address listed in Appendix B. warranty
card.

1-2

Chapter 1 - Introduction

Required Equipment

In addition to the ZyXEL Omni 288S modem you just purchased, you must have
the following equipment to operate your modem:

 Computer terminal
 Available PC serial port with a high-speed 16550 UART
 Standard "straight-through” RS-232 cable (pins 1-8, 20, 22)
 Available telephone jack
 Available AC wall outlet
 Telephone line from your telephone company (dial-up or leased line)
 Data, fax, and voice communication software

Optional Equipment

The following items are optional for installing your Omni 288S:

 Telephone for manually dialing and answering calls
 Microphone for recording voice messages
 Speakers for listening to recorded messages

Becoming a Registered Owner

Complete the pre-addressed Warranty Registration Card and place it in the mail.
Registered owners will receive future product information and update
announcements. Warranty registration is not necessary for product repair/or
replacement - please also save your

dated invoice

as proof of purchase.

Omni 288S Modem Features

No other 28.8Kbps modem gives you so much for so little. Your Omni 288S is
equipped with an array of standard and ZyXEL-famous Intelligent features
designed to make your data communications faster, easier, and more convenient.

Standard features

 Ultra-high speed modem - supports V.34 for 28,800bps and backwards

compatible

 Operates in all environments: Windows 95, DOS, Windows, Macintosh,

OS/2, UNIX, Novell, Amiga, and IBM AS400/RS6000

 V.42 and MNP 4/3 error correction
 V.42bis and MNP 5 data compression
 DTE serial interface with speeds up to 460.8Kbps

1-3

Chapter 1 - Introduction

 13 LED lights
 Extended AT command set with V.25bis
 ZyCellular Protocol for demanding cellular operations - data and fax

transmission over cellular networks

Intelligent Features

 Automatic data, fax and voice call detection allows you to use a single

telephone line to handle all three types of calls

 Asynchronous and synchronous modes for reliable serial data communication
 Fast retrain with automatic fall-forward and fall-back - the Omni 288S will

automatically fall back to lower speeds when communicating with slower
modems and when encountering unstable or variable line conditions..

 Call-back security and password protection restricts access to authorized

callers only.

 Caller ID identifies incoming calls before you answer (you must subscribe to

this service through your telephone company in order for your Omni 288S to
identify callers)

 Distinctive ring detects data, fax and voice calls (this feature requires

communication software that supports distinctive ring, such as ZFAX)

 Remote configuration capability
 EDR (extended Distinctive Ring)
 Flash EPROM memory lets you easily upload new firmware, providing you

with easy access to new features.

 ZyXEL exclusive Kernel Recovery Mode for no hassle recovery from failed

flash uploads - no factory repairs.

Fax Compatibility

 EIA Class 1, 2, and 2.0 Fax commands
 ITU-T V.17 G3: up to 14,400bps
 ITU-T V.29 G3: up to 9,600bps
 ITU-T V.27ter G3: up to 4,800bps
 ZyXEL Fax AT commands

Voice Features

 TAPI support links the power of telephones and communication networks

with your computer

1-4

Chapter 1 - Introduction

 Microphone jack is provided to increase the quality of voice recordings
 Speaker jack lets you plug in an external speaker for clearer output of

recorded messages.

 2, 3, 3-bit new and 4-bit ADPCM for high quality voice digitization with

speech compression at 19.2Kbps, 28.8Kbps, 30.7Kbps, and 38.4Kbps

 Simultaneous DTMF, dial-tone, answer tone and fax/data calling tone

detection

 Voice AT+V (IS-101) command set

Technical Specifications

 Operating mode: auto-dial/answer
 Flow control: software XON/XOFF or hardware CTS/RTS
 Data/Voice toggle switch
 Configuration settings: software programmable with nonvolatile memory for

phone number/profile storage

 Diagnostics: self test, analog loopback (with self test), digital loopback, and

remote digital loopback (with self test)

 Dialing type: tone/pulse dialing
 Line interface: RJ-11 2-wire dial-up or leased line
 Call progress monitoring: dial tone, busy, and ring back detection
 Audio Monitor: programmable volume control

1-5

Chapter 2 - Installation

Chapter 2 - Installation

This chapter covers the steps required to install your modem, install and configure
the Windows 95 driver, as well as optional steps you may wish to take in the
setup of your Omni 288S. More detailed instructions for various types of
computers, such as IBM PCs and compatibles, Macs, and UNIX workstations, can
be found in Chapter 3 of this Manual.

Required Steps for Omni 288S Installation

1. Turn off your computer.

2. Make sure the modem's power switch is in the OFF position.

3. Connect the power adapter. Plug one end of the power adapter to the round
POWER JACK on the back of the modem. Plug the other end to an AC wall
outlet. You can leave the power adapter plugged in when you are not using
the modem. To prevent power surges from damaging your modem and
computer, it is recommended that you connect the power adapter to a surge
protector.

Power To To Serial To Line To Phone
Switch Power Port (wall jack)

Supply

Caution: Use only the power adapter suppli ed with your modem. Never

use a power adapter designed for a different product.

4. Connect the serial cable. Plug one end of the serial cable into the SERIAL
connector on the back of the modem. Plug the other end of the serial cable to
the back of your computer. Your Omni 288S comes with a high-speed serial
interface capable of reaching DTE speeds of 460.8Kbps. Be sure that your
PC serial port has a high-speed 16550 compatible Universal Asynchronous
Receiver Transmitter (UART).

Note: Many older computers use a slow 16450 UART. This UART was

not designed for high-speed communications and will
significantly impede the performance of the Omni 288SS. To
check whether your computer has a 16550 compatible UART,
use a utility such as Microsoft Diagnosti cs (MSD) to veri fy t he

2-1

Chapter 2 - Installation

type of UART installed in your computer. If your computer has
a 16450 UART, either r eplace it wit h a 16550 UART or add a
serial card with a 16550 UART to your system.

5. Connect the telephone cord. Plug one end of the supplied telephone (RJ-11)
cord into the LINE jack on the back of the modem. Plug the other end into a
telephone wall jack, just as you would a standard telephone.

6. Turn the computer back on.

7. Turn the Omni 288S back on by raising the power switch. The PWR LED
should come on and the modem performs a self-test procedure.

Note: If the modem’s SQ LED is flashing, it has failed the self-test.

Consult Chapter 13 of this Manual for troubleshooting
information.

Optional Steps for Omni 288S Installation

The Omni 288S is equipped with a telephone jack and speaker and microphone
jacks on the back panel. The following sections briefly describe how to take
advantage of these features.

Telephone Jack

Connect a telephone to the PHONE jack on the back panel of the modem to
manually dial and answer calls when the modem is not exchanging data.

Microphone

To connect an external microphone, connect it to the modem’s MIC jack on the
back of the modem. The microphone jack can accommodate input from a standard
600 Ohm microphone.

Speaker

To connect an external speaker, connect it to the modem’s SPK jack found on the
back of the modem. The modem’s speaker jack accommodates a single 8 Ohm

2-2

Chapter 2 - Installation

speaker. To connect two speakers, obtain a dual-plug adapter that allows the
modem speaker jack to drive both speakers. This adapter can be found at most
electronics stores.

Driver and Software Installation

This section contains step by step procedures for installing the Windows 95 and
NT drivers, and configuring Dial-up Networking for the Omni 288S.

Windows 95 Driver Installation

Open the Control Panel by double clicking the "Control Panel" icon in your "My
Computer" folder.

Double click "Modems.” Then click the "Add" button. The following dialog box
will appear.

Select "Don't detect my modem; I will select from a list..” Then click "Next.”

Click the "Have Disk" button.

2-3

Chapter 2 - Installation

Insert the ZyXEL Windows 95 driver disk into your floppy drive and click OK. If
you have downloaded an updated INF file from ZyXEL’s FTP, Website, or BBS,
use "Browse" to find the location of the updated .INF file, click "Open.” Then
click "OK.”

Select Omni288S from the list. Then click "Next.”

Select the COM port your modem is connected to and click "Next.” A final
dialog will appear. Click "Finish.” You should see a window similar to the one
below.

2-4

Chapter 2 - Installation

Click "Close.” This completes the installation of your Omni 288S modem driver.
You may now use programs such as "Dial-Up Networking" with your ZyXEL
modem.

Windows 95 Dial-up Networking

If you have not installed the Dial-Up Networking feature in Windows 95, please
install it before you continue.

Double click on the "My Computer" icon and then double click on the "Dial-up
Networking" icon. From within the Dial-up Networking folder, double click on
the "Make New Connection" icon.

Choose a name for your connection and select your modem type from the drop
down window. Then click on the "Next" button.

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Chapter 2 - Installation

Enter the phone number to your ISP or whatever host you are calling into. Click
on the "Next" button.

Click on the Finish button. A new icon is created in the Dial-up Networking
folder.

Right click on this icon. Then select "Properties" from the menu.

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Chapter 2 - Installation

Make sure your Omni modem appears in the "Connect Using.” Then click on the
"Server Type" button.

These options are mostly host or server specific.

 If you are using PPP, use the default settings shown above.
 If you are logging on to an Internet connection, then select "TCP/IP.”
 If you are connecting to a LAN, then select "Login to Network.”
 If you are logging on to a Microsoft Windows network, select "NetBEUI.”

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Chapter 2 - Installation

 If you are logging on to a Novell network, then select "IPX/SPX

Compatible.”

Once complete click on "TCP/IP Settings.”

If your host requires you to specify an IP address (Static IP), then click on the
"Specify and IP address" radio button and enter your IP address. If your host
assigns an IP when you log in (Dynamic IP), then leave the "Server assigned IP
address" checked. Most servers assign an IP to you when you log in.

Click the "Specify name server address" radio button and enter your primary and
secondary DNS (Domain Name Server) IP.

In most cases, you should leave "Use IP header compression" and "Use default
remote gateway" checked. When all of the selections have been made, click the
"OK" buttons on all three opened dialog boxes.

This completes the remote connection definition. Locate the new connection icon
in your "Dial-up Networking" folder, and double click on it.

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Chapter 2 - Installation

If the User name and Password are incorrect or missing, type them in. Click on the
Connect button and your Omni 288S will dial the number and establish a
connection to your Internet Service Provider.

Note: The default pr otocol for Dial -up Networki ng is Point-t o-Point

Protocol (PPP). If your ISP requires you to use Serial Line
Interface Protocol (SLIP), you may need to create a special
logon script file. Because the procedures for logging on with
SLIP accounts vary greatl y from ISP to ISP, you should cons ult
the technical support department of your service provider for
this information.

Setup for DOS Fax/Modem Software

After installing the Omni 288S, use the following procedures to verify your
modem connections.

1. Install and load your communications software. If you need assistance, refer
to the manual that came with the software.

2. If your communications software requires you to select a modem, and the
ZyXEL Omni 288S is not one of the choices, you can either check our web
site for the driver or select the ZyXEL U-1496 modem. In many cases, the
commands for these modems are identical.

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Chapter 2 - Installation

3. Select the following communication settings:

Setting Value

Baud rate 57,600bps
Data bits 8
Parity None
Stop bits 1
Flow control Hardware
Initialization string AT&F
Port COM n*

Note: When specifying a port assignment, the ‘n’ indicates the

computer serial port to which your modem is attached. For
example, if your modem is connected to serial port 2, you would
select COM2.

4. Place your communications software in terminal or direct connect mode
(your communications software manual will explain how).

5. Look at the modem’s front panel and verify the DTR LED is ON. If this LED
is OFF, your communications software is not addressing your modem at the
correct COM port. Make sure your software is set up for the same COM port
to which your modem is connected.

6. Type AT and press the Enter key. You should see the AT characters you
typed, followed by an OK result code. If you do not see an OK result code,
turn the modem off and on, then repeat this step. If you still cannot see the
characters, refer to Chapter 13 for troubleshooting suggestions.

7. Type ATDT number and press Enter, where number is your modem’s
telephone number. You should see a BUSY result code. If you do not see a
BUSY result code, refer to Chapter 13 for troubleshooting suggestions.

If you are not able to successfully complete this test and have already followed
the appropriate troubleshooting procedures Chapter 13, please call ZyXEL Tech
Support at 714-693-0808.

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Chapter 3 - Basic Modem Operation

Chapter 3 - Basic Modem Operation

This chapter covers the basic commands and techniques involved in modem
operation. In many cases, this is the only information you will need in order to get
your Omni 288S up and running with communication software, and to start making
connections with your Omni 288S.

Understanding AT Commands

The Omni 288S communicates asynchronously with computers using AT
commands. AT commands are used to configure and control the Omni 288S.
Commands are usually sent to the modem by way of communication software, but
can also be entered manually by the user with the computer keyboard.

Command statements must be written in a specific form in order for the Omni
288S to recognize them. A command statement always begins with the letters AT
or at. It is then followed by one or more commands and the <Enter> key.

AT commands can only be issued when the Omni 288S is in “command mode” or
“off-line.”

Once the Omni 288S has established a connection with another modem it is said
to be “on-line” or in “data mode.” In this mode, the characters sent to the Omni
by your computer are transmitted to the remote modem rather than being
interpreted by the Omni as commands.

Using the Windows 95 Hyper Terminal Program

In order to issue an AT command statement, you first need to run a communication
program such as the Microsoft Windows “Hyper Terminal” program. This
program provides a simple method to manually enter AT commands so you can do
such things as “customize” the settings of your Omni 288S, or store phone
numbers you commonly will connect to.

Once the Omni is connected to your computer’s serial port and telephone line,
Open the Windows 95 “Accessories” program group, and open the Hyper
Terminal Program.

The program will prompt you for a name and Icon to use for your new connection.
Type the name Test Connection and press <Enter>.

Next, you will be prompted for country information, area code and phone number,
and the device used to make the connection. For this test purpose, do not enter a
phone number; simply choose the COM port your Omni is connected to from the
“Connect Using” list. Click “OK” when finished.

The next window sets the COM port settings. The settings used for The Omni
288S should be as follows.

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Chapter 3 - Basic Modem Operation

Bits per second: 57600
Data bits: 8
Parity: None
Stop bits: 1
Flow Control: Hardware

Click “OK” when finished. After you have done this, save your new connection
by selecting “Save” from the “File” menu and click “OK.” A new connection
icon will be added to your Hyper Terminal folder.

You are now ready to start entering AT commands.
In the terminal window, type:

AT<Enter>

Omni 288S responds

OK

This confirms that the modem and your computer are communicating correctly.
To test the telephone line connection issue the manual answer command.
Type:

ATA<Enter>

The Omni 288S will pick up the phone line, and try to communicate. Normally,
this command is only used to answer an incoming call made from another modem.
Thus the high pitched noise you will hear from the speaker. To abort the
operation, press any key, or select “Disconnect” from the “Call” menu.

Dialing and Answering Techniques

Depending on what communications software you use to make modem
connections, you may not have as much control of how the modem dials the
telephone number. This section shows some useful examples of the AT commands
used for dialing and answering operations. The command characters specific to
each function are shown in bold type.

Dialing using the ATD Command

Touch Tone Dialing: ATDT 555 1212
Pulse Dialing: ATDP 555 1212
Tone and Pulse Dialing: ATDP 555 1212 WT 24
Dialing Through a PBX: ATDT 9 W 555 1212

Note: The 'W' in the dial string will cause the modem to wait for a

second dial tone before it continues to dial.

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Chapter 3 - Basic Modem Operation

Pausing During Dialing: ATDT 9,,555 1212

Note: The pause time for each comma is defined by S Register S8.

Default is 2 seconds per comma.

Dialing Without Waiting for Dial Tone: ATX0D, 555 1212
Originating a call using an Answer Tone: ATDT 555 1212,,,,,,R
Redialing the Last Number Called: ATDL
Waiting for Five Seconds of Silence: ATDT 800 555 1212 @

123456,1 714 555 1212

Transferring a Call (using flash hook): ATDT! 2468

Auto-Answer and Hook Controls

Enabling Auto-Answer: ATS0=n

Note: In this example, n is a number from 1 to 255 that corresponds to

the number of rings after which your modem answers an
incoming call.

Disabling Auto-Answer: ATS0=0
Manually Answering a Call: ATA
Take modem off-hook: ATH1
Hang up modem (on-hook): ATH0
Manually Disconnecting a Call: +++ATH

Making Your First Connection

For this example, we will use the connection you created in the Hyper Terminal
program to dial the ZyXEL BBS. If you are using a different terminal program, run
the program according to the instructions provided with it.

Start the terminal program by double-clicking the Test Connection icon. When
the terminal window appears, enter the dial command with ZyXEL’s BBS as the
phone number.

Type:

ATDT17146930762<enter>

The modem will go off-hook, dial the number, and after a few seconds of
negotiation tones, you should be connected to our BBS.

You will receive a login message asking for your name. For the purposes of this
example you need not continue. Just click the “disconnect” icon on the toolbar.

(Omit the ‘1714’ if you are in this area code)

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Chapter 3 - Basic Modem Operation

Quick Tips when issuing AT Commands

 The ENTER or RETURN key must be pressed to execute a command.
 Multiple AT commands can be combined into one line. For example,

AT&D2 and AT&N0 can be combined into one line AT&D3&N0.

 The Omni 288S processes commands from left to right. The AT command

that appears to the right might over-write the command to the left if they are
trying to accomplish tasks or set modes that cannot coexist.

 If you see duplicated characters for each one you type, your Omni 288S and

software both have their “echo” feature turned. The Omni 288S command
echo state is switched off using ATE0 and on using ATE1 (default). To
eliminate the double characters, turn off the software’s command echo rather
than using the ATE0 command. If you see no characters in your terminal
window when you type, the modem’s echo setting is probably set to off. In
this case, issue the ATE1 command.

 When a command is successfully issued and accepted, a modem responds

with what is called a “Result Code.” The Omni 288S supports both
“verbose” result codes (i.e. “OK”), and “numerical” result codes (i.e. “0").
You can use the ATV command to set it one way or the other as follows.

Command Description

ATV0 Select numerical result code
ATV1 Select verbose result code

 There are a few basic commands that do not require the “AT” command

prefix. These are as follows.

Command Description

A/ Repeats the last issued AT command once
A> Repeats the last issued AT command once, or re-dials

the last dialed number up to 9 times until a key is
pressed or a connection is made.

<any key> Terminates the current connection attempt, if pressed

while modem is handshaking.

+++ Escape code sequence. Entered while the modem is in

Data Mode. Returns modem to Command Mode.

 The Omni 288S supports several groups of AT commands:

AT Command Set/Type Example

Basic AT (Hayes compatible) ATB0
Basic AT$ (on line help) AT$
Extended AT& commands AT&N0
Extended AT* commands AT*I1

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Chapter 3 - Basic Modem Operation

AT Command Set/Type Example

Fax and Voice AT+ commands AT+FCLASS=2
S-Register command ATS0=1
S-Register bit-mapped command

Register bit 1 equal to 1)

(set S-

ATS13.1=1

S-Register inquiry command ATS0? Or ATS13.1?

You may browse the lists of available commands for each command set by using
the on-line help commands: AT$, AT*$, AT&$, and ATS$. Further detail on AT
commands will be covered in the chapters that pertain to their uses.

Modem Result Codes

When you execute or try to execute an AT command, your modem sends a result
code to let you know whether the command was executed. An OK result code
means the AT command you sent was executed. If you receive an ERROR code, it
means the command was invalid.

The Omni 288S also provides result codes that show:

 Whether or not a Dial Tone was detected when the modem originated a call.
 If a busy signal was detected when the modem originated a call.
 If a remote telephone ring was detected when dialing.
 The speed, protocol, and error control / data compression method used.
 If your modem has detected an incoming ring.

Result codes can originate from any of eight result code sets. The ATXn
command lets you choose which set of result codes your modem uses. By default,
your modem uses result codes equivalent to the ATX5 command.

The result code options will be covered more thoroughly in later chapters.

Viewing S Register Values

Status registers (or "S-registers") contain values that determine the modem’s
operating characteristics. Whenever you send an AT command to your modem,
you are actually changing the value of an S-register.

You can use the Sr? command to view the value of S-register ‘r’. For example,
to view the value of S-register S0, which controls auto-answering, type ATS0?
and press Enter. The modem responds with a three-digit character showing the
value of this register, followed by OK. A value of 002, for example, means your
modem will auto-answer incoming calls after the second ring.

Some S-registers are bit mapped. For these registers, you can use the Sr.b?
command to read their values.

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Chapter 3 - Basic Modem Operation

For example, to read the value of S-register S35, bit 7, type ATS35.7? and press
Enter. The modem responds with an appropriate value, followed by OK.

Changing S Register Values

You can use the ATS0=n command to change the value of an S-register.
For example, to have your modem auto-answer an incoming call after two rings,

set S-register 0 to 2. Be sure the n value is between 1 and 255. If n is set to 0,
your modem will not answer incoming calls.

Non-Volatile Memory

The Omni 288S has an amount of memory set aside for storing user information
such as frequently used phone numbers and default command settings. This latter
is particularly useful when you use your modem to call a variety of different
locations that require different settings. For this reason, the Omni 288S provides a
number of user “Profiles” that can be accessed through simple AT commands.
This section covers the topics of storing phone numbers, and saving default
settings in the power-on profile.

Storing Phone Numbers

The AT command to store a phone number is in the format AT&Zs=n.
The ‘s’ is a number from 0 to 49 that represents the location in memory that the

phone number is to be stored, and the ‘n’ is the phone number itself.
Example: To store the number ‘1-714-555-1212’ in memory location ‘2’, type:

AT&Z2=17145551212<Enter>

You can store up to 50 telephone numbers.

Dialing Stored Phone Numbers

The AT command syntax used to dial a store number is ATDS=n.
The ‘n’ is the memory location of the stored number you want to dial.

Note: As a general rule, when a letter in an AT command definition is

shown in italic type, the letter is not to be entered as part of the
command, but rather is representative of a number or string
expected as i nput. For example: The le tter ‘S’ i n the ATDS=n
command is actually typed, unlike the ‘s’ in the AT&Zs=n
command which represents a number.

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Chapter 3 - Basic Modem Operation

Saving Settings and User Profiles

There are some cases where you may wish to save the settings you have made as
the default settings that are recalled when the Omni 288S is powered up. The

AT&WZ

command selects the current settings as the power-on profile.

There are four profiles that can be changed by the user, and one factory default
profile. The following table lists the syntax for the command involved in storing,
recalling, and viewing the profile settings.

AT&V
AT&W
ATZ

n

Profiles 0 to 3: User profiles
Profile 4: Factory default profile

Views the settings in profile (

n

Stores the current settings in user profile

n

Resets the current settings with the settings in profile ‘n’, n=0 to 4

); n=0 to 5; n=0 views current settings

n-1

=0 to 3

‘n’; n

Helpful Hints for PC Computers

Most PCs are equipped with more than one serial port. Standard cables are
readily available from many suppliers. Usually, serial ports are manufactured in
two forms, either with a 25-pin male jack or a 9-pin male jack. For high speed
serial connections at 230.4Kbps or 460.8Kbps, use a low-capacitance cable.
Also, keep the cable as short as possible.

The serial port is driven by interrupts. Every interrupt needs a certain amount of
overhead processing time. Too many interrupts reduce the computer's efficiency.
The UART 16450 is very commonly used in serial port devices. For every
character (byte) received, it generates an interrupt. If your hardware allows it and
if your software supports it, replace the 16450 UART with a 16550 model. This
newer chip has an internal buffer and generates an interrupt for up to every 16
characters (several trigger levels are available). With this UART installed, you
may drive your serial port at 57600 bps and above.

While data is written from the transfer-buffer to your hard-disk, characters may be
lost at the serial port. This is due to the fact that disk-access interrupts have a
higher priority than serial port interrupts. If you are running at a high serial speed,
e.g. 230.4Kbps or 460.8Kbps, on your PC, be sure to enable the disk cache by
including SMARTDRV execution in your AUTOEXEC batch file.

Default Modem Settings for PC’s

The Omni 288S factory settings are configured for operation with PC type
computers and comm software. In most cases, no additional settings will be
required. The following are some of the default settings that are used for
operation with PC computers and software.

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Chapter 3 - Basic Modem Operation

AT Command Description

E1 Echoes command characters
&C1 Carrier detect follows remote carrier
&D2 Modem disconnects on DTR on-to-off transition
&K4 Use both V.42 and MNP 4 error correction, and use

both V.42bis and MNP 5 data compression

&N0 Modem negotiates highest possible connection speed

ZyXEL Serial/Parallel I/O Card

For high-speed PC to modem communication, ZyXEL produces the special I/O
adapter card. This card includes a serial port and a parallel port, each with
special features, particularly when working with a ZyXEL modem, for example:

The serial port is 16550-compatible for most comm software's usage. It has a
speed of up to 460.8Kbps and data loss errors will not occur when working with
a ZyXEL modem's serial port. This solves high-speed communication problems in
Windows and other multi-tasking systems. The serial port has a 32-byte
transmission and a 32-byte receival FIFO to increase any comm program's
efficiency.

Helpful Hints for Mac Computers

Special AT Command Settings for Mac

For operation with Mac computers, you may use the factory default settings with
one exception. You must set the modem to ignore the DTR signal as follows.

Type:

AT&D0<enter> (set modem to ignore DTR)
AT&WZ<enter> (saves the settings to power-up profile)

Mac Serial Port

When you connect your Omni 288S modem to a Macintosh computer, make sure
the cable is a hardware handshaking cable. These cables are readily available.
The models Lisa, Macintosh 128 and Macintosh 512 don't have hardware
handshaking. The serial port on these (very outdated) models is provided as a 9­pin connector similar to that of a PC. The serial port on all other Macintosh
models is a Mini-8.

Mac Software Tips

All terminal programs which make use of the hardware handshaking feature can
be used on the Apple Macintosh. Such programs are readily available as PD,
shareware or commercial software. One of the most powerful shareware
programs available is ZTerm.

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Chapter 3 - Basic Modem Operation

Fewer programs are available to make use of the ZyXEL's fax features. A
commercial software which has found wide acceptance is FaxSTF. It is installed
like a printer driver, thus allowing you to send faxes from almost any program
which runs on your Macintosh. At the same time it allows automatic fax receiving.
This program includes a powerful line manager software which makes sure that
the fax software does not interfere with other programs using the serial ports. If
the modem is turned off when you start your Macintosh with the line manager
activated, the computer may seem to freeze for a few minutes. During this time the
line manager software tries to locate and to set up the modem. Turn on your
modem before you start your Macintosh to avoid this delay.

MaxFax is another fax software for Macintosh computers. On top of the fax
handling, it allows you to make use of the Omni’s voice features.

Drivers are available which allow use of the serial ports at speeds up to 230.4
Kbps. These drivers are currently available for Power Macs and AV Macs only.

Helpful Hints for UNIX-Based Computers

Serial Cable

Please consult the documentation that came with your workstation to find the part
number of or information on how to make a serial cable for your workstation. The
cable should be a hardware-handshaking cable. Please refer to Appendix A for a
complete list of signals provided by the modem its serial port.

Basic Modem Settings for UNIX

Unix environments usually don’t like modem responses or echoing of commands.
Therefore you should set

Depending on your of Unix, the cable and software used, you may have to disable
carrier detection using

ATE0Q1

AT&C0

.

.

Unix Software Tips

In order to use your ZyXEL modem from a terminal screen or an X-Windows
application, you need a program such as minicom or seyon, respectively.

If you wish to make use of the ZyXEL modem' special features such as voice,
special gettys such as mgetty or vgetty are needed. These programs are avaiable
from several ftp-sites. Some archives also contain source files.

You should suppress the modem's result codes (
applications may be confused by them.

3-9

) because some

ATQ1

Chapter 4 - Advanced Data Communications

Chapter 4 - Advanc ed Data Communica tions

This chapter is included as a general reference to the connectors, interfaces,
protocols, and standards used by the Omni 288S, including definitions of many of
the communications-related terms used in this manual.

Front Panel LEDs

The Omni 288 has 13 front panel LEDs. Some LEDs have individual meanings,
while others work in combination to apprise you of your modem’s operating
status. For example, the AA LED is ON when auto-answering is enabled, while
the V34 and V32b LEDs together show the connection mode and speed.

Refer to the following tables for details on the LED status indicators and their
meanings.

LED State Indicates Status

AA ON Modem will automatically answer incoming calls.

OFF Modem will not auto-answer incoming calls.

CD ON Modem has detected a valid carrier signal, or &C0 is set.

OFF No carrier detected.
TXD ON Computer is transmitting data to the modem.
RXD ON Computer is receiving data from the modem.
DTR ON Computer is ready for data communications.
DSR ON Modem is ready for data communications.
RTS ON Computer requests to send data.
CTS ON Modem is ready to accept data for transmission.
EC ON Modem is using V.42 or MNP 4 error correction, or V.42bis

or MNP 5 data compression.

Blinking Data is being re-transmitted.
SQ ON Good signal quality

Flashing Marginal signal quality or error condition at power-up.
OH ON Modem is accessing telephone line.

OFF Model is off-line or not accessing the telephone line.

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Chapter 4 - Advanced Data Communications

LED

V34 V32B Indicates Status

OFF OFF Modem is in V.22bis, V.22, or mode slower than 9600bps.
OFF ON Modem is in V.32bis or V.32 mode.
ON OFF Modem is in V.34 mode.
ON ON Modem is in a ZyXEL proprietary mode

(ZyX 19.2, ZyX 16.8, or ZyCellular).

DTE Interface

DTE and DCE are terms used in data communication. DTE stands for Data
Terminal Equipment and DCE stands for Data Communication Equipment. The
computer or terminal is the DTE and the modem is the DCE. The DTE interface
used by the Omni 288S is an RS-232 with throughput speeds up to 460.8 Kbps.

Synchronous and Asynchronous Communications

There are two kinds of serial data communication. One is called synchronous, and
the other is called asynchronous. In synchronous communication, data is
transmitted and received bit by bit and is timed by an accompanying clock signal.
In asynchronous communication, data is sent character by character (or octet by
octet), and the idle time between characters is variable. Since no clock signal is
sent, character timing is recovered from the data itself.

A PC's COM1 and COM2 are asynchronous serial ports. Most PCs' and UNIX
systems' serial data communications are asynchronous. The serial data
communication on an IBM mainframe or mini is synchronous.

UART

A UART (Universal Asynchronous Receiver Transmitter) is the device used in a
DTE or DCE for asynchronous data reception and transmission. The standard
UART device used in PCs is of the NS16450 type. For high-speed serial data
transfers (38400 bps and up), the PC may not serve the UART fast enough and
data may be lost. In this case, a UART with data buffer is needed, such as the
NS16550A type device.

Serial Port

A serial port is the serial data connector together with its internal circuit on the
DTE or DCE with electrical and mechanical characteristics according to RS­232C. Since some signals travel from the DTE port to DCE port, and some
signals travel in the opposite direction, the signal pin is a transmitter on one port
and a receiver on the other. The DTE serial port is different from the DCE serial
port in terms of signals on the connector pins. There are also mechanical
differences in terms of male (with pins) or female (with holes) connectors.

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Chapter 4 - Advanced Data Communications

RS-232C or EIA-232D/E

RS-232C is the Recommended Standard (RS) of the Electronic Industries
Association (EIA), defining the serial communication interface between a DTE
and a DCE. The 232 is basically a serial number for the defined standard.
Sometimes it is necessary to redefine a standard, or to revise it. The most
commonly used revision of the RS232 standard is the "C" revision. For the "D"
revision, the prefix was changed to EIA. Except for a few signals which were
added but not commonly used, there is no practical difference between the "C"
and "D" revisions. There is now a new revision with the "E" suffix. The RS-232C
standard is equivalent to the ITU-T V.24 and V.28 standard.

Serial RS-232C Cable

A serial RS-232C cable is used to connect a DTE port to a DCE port. Do not use
a null-modem cable (which may be used to connect two DTEs directly with each
other through their serial ports). A normal RS-232C connector has 25 pins, and a
normal RS-232C cable has 25 wires. Many signals in the RS-232C are not used
in common applications, and a 9-wire RS232C cable is sufficient in most
applications. The PCAT's serial port has only 9 connector pins, thus eliminating
unnecessary pins. For high-speed DTE-DCE communication, use a low­capacitance cable (as short as possible).

Communication Protocols and Speeds

The ITU-T or ITU-TSS (International Telecommunications Union ­Telecommunications Standardization Sector) is the international standard-making
body for telecommunications. Their primary function is to draft recommendations.
The recommendations they make for modem applications have a "V" prefix and
are called V-series recommendations. The most commonly used ITU-T modem
standards for 2-wire dial-up lines are summarized in the chart below.

Standard Speed (bps)

V.34 28,800 ~ 2 400
V.32bis 14,400 / 12,000 / 7,200
V.32 9,600 / 4,800
V.22bis* 2,400 / 1,200
V.22 1,200
V.21 300
V.23 1,200 / 75

* bis is the old French word for second
In the USA, Bell Systems used to create de facto standards such as Bell 212A for

1200 bps modems and Bell 103 for 300 bps modems. Everyone follows the ITU­T standards now for newer and higher-speed modems. The Omni 288S supports
all the above mentioned modem standards and are compatible with existing
modems.

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Chapter 4 - Advanced Data Communications

Universal Protocol Compatibility

Universal compatibility covers a broad range of ITU-T and BELL standards, and
provides data compression.

Various operation modes that can be achieved are as follows:

Standard BPS rate

(+/-0,01%)

V.34 28 800 - 2 400 multiple multiple multiple
ZyXEL 19 200 2 74 3
ZyXEL 16 800 2 40 0
V.33* 14 400 2 400 128-TCM 1800
V.33* 12 000 2 400 64-TCM 1800
V.32bis 14 400 2 400 128-TCM 1800
V.32bis 12 000 2 400 64-TCM 1800
V.32bis 7 200 2 400 16-TCM 1800
V.32 9 600 2 400 32-TCM 1800
V.32 uncoded 9 60 0 2 400 16-QAM 1800
V.32 4 800 2 400 4-DPSK 1800
V.29* 9 600 2 400 16-QAM 1700
V.29* 7 200 2 400 8-QAM 1700
V.29* 4 800 2 400 4-DPSK 1700
V.27bis* 4 800 1 600 8-PSK 1800
V.27bis* 2 400 1 200 4-DPSK 1800
V.26bis* 2 400 1 200 4-DPSK 1800
V.23 1200 / 75 1200 / 75 FSK
V.23 600 / 75 600 / 75 FSK
V.22bis† 2 400 600 16-QAM 1200 Orig.

V.22† 1 200 600 4-DPSK 1200 Orig.

V.21 300 300 FSK
BELL 103 300 300 FSK
G3 FAX Implemented according to T.30, V.17,V.29 and V.27ter.
Cellular Modes ZyXEL proprietary cellular modes; 14400 bps to 4800 bps.

Baud rate
(+/-0,01%)

Modulation Carrier Freq

[Hz]

2400 Ans.

2400 Ans.

Choosing the Modem Link Options

The Link options or protocol negotiation settings are controlled by the
command. The default setting is

. The modem will execute an auto-handshake

&N0

sequence to determine the protocol being used by the remote modem, and connect
at the highest allowable speed.

The link options can also be set to force negotiation to any one of the protocol
options listed in the above table using

&N1

to

. If the modem cannot

&N73

successfully negotiate the protocol that was set, connection will be refused, and
the modem will release the line. For specific settings, please refer to Chapter 11.

4-4

&N

Chapter 4 - Advanced Data Communications

Certain modes, such as the ZyXEL proprietary modes, Fax mode, and Cellular
modes can be added or omitted from the auto-negotiation process using the S­registers settings listed below.

Mode Disable Enable

ZyXEL 19200 S43.1=1 S43.1=0 *
ZyXEL16800 S43.0=1 S43.0=0 *
G3 Fax S38.4=1 S38.4=0 *
Cellular S43.3=1 * S43.3=0

* Denotes default setting.

Setting the DTE to DCE Rate

The Omni 288S DTE to DCE rate can be determined in three ways:

1. By default the DTE to DCE rate is equal to the DTE speed set by S20
(default S20=1 for 115200 bps). This mode is set with &B1.

2. To set the DTE to DCE rate to follow the connect speed, set &B0.

3. To force the modem to use a fixed baud rate when answering, set S18 to the
corresponding value.

S18= Speed S18= Speed

0 * Disable fixed rate 15 300 bps
1 115200 bps 16 307200 bps
2 76800 bps 17 153600 bps
3 57600 bps 18 102400 bps
4 38400 bps 20 61440 bps
5 19200 bps 21 51200 bps
6 16800 bps 22 624000 bps
7 14400 bps 24 124800 bps
8 12000 bps 25 62400 bps
9 9600 bps 26 41600 bps
10 7200 bps 27 31200 bps
11 4800 bps 28 24960 bps
12 2400 bps 29 20800 bps
13 1200 bps 32 230400 bps
14 460800 bps 46 921600 bps

* Denotes default setting

Error Control

Error control keeps the modem data link error-free by detecting and re­transmitting erroneous data. ZyXEL modems support both MNP and V.42 error
control protocols. The MNP protocol was an industry de facto standard
developed and licensed by Microcom, Inc. ZyXEL modems support level 4 and 3

4-5

Chapter 4 - Advanced Data Communications

error control protocols, commonly denoted as MNP4 and MNP3. V.42 is a
standard developed by ITU-T. V.42 supports both LAPM (Link Access Procedure
for Modem) and MNP4. A V.42 handshake will try an LAPM connection first, and
if not successful, it will try MNP4.

The error control (MNP4, LAPM) methods in modem to modem connections are
based on techniques utilized by both modems. They are explained below.

CRC (Cyclical Redundancy Check) Error Detection

At the end of every data block, a 16-bit number CRC, which is calculated through
a polynomial function, is sent. The receiving modem receives the block,
calculates its own CRC through the same polynomial function, then compares the
numbers. If it matches the received CRC, everything is all right. If not, an error(s)
has occurred somewhere in the block. The modem checks every block received
for error(s).

Automatic Re-transmission Request (ARQ) Error Correction

Once a data block is received error-free, the receiving modem will acknowledge
this block immediately. The sending modem receives the acknowledgment and
will check if any block(s) is(are) not acknowledged. Let us assume 18 blocks
were transferred and the first 14 blocks were acknowledged. If no
acknowledgment for block 15 is received in a given time, this block must have
been damaged. Acknowledgments of blocks 16 through 18 are ignored. Blocks
starting from 15 are resent.

ARQ Error Correction with Selective Reject

ZyXEL modems support V.42 error control with selective reject. Using this
feature, the modem only re-sends the erroneous data block(s), not all the data
blocks starting from the one in error (just block 15 in the above example). This
saves retransmission time and greatly improves efficiency in high error rate
situations.

Data Compression

The Omni 288S supports both V.42bis and MNP5 data compression protocols.
Data compression works by representing the original data information in less bits
and transmitting the reduced data bits through the data link. The receiver recovers
the original information by reversing the representing process. The process of
representing original data in less bits is called redundancy removal.

Data compression needs an error-free data link to work correctly. MNP5 is used
with MNP4 error control and V.42bis is used with V.42 error control.

MNP5 data compression utilizes the run-length encoding and adaptive frequency
encoding techniques. V.42bis uses a string coding algorithm.

4-6

Chapter 4 - Advanced Data Communications

The compression efficiency of V.42bis is generally higher than that of MNP5. In
some cases it can be 50% to 100% higher and in other cases it is just slightly
higher. In general, it is about 50% more efficient.

Run Length Encoding

Run-length encoding is applied in an attempt to avoid sending long sequences of
repeated characters (data). When three or more repeated characters appear in
succession, only the first three tokens (representing the compressed format of that
character) and a repetition count will be sent.

Adaptive Frequency Encoding

Adaptive frequency encoding is applied after removing repeated characters
(data). In adaptive frequency encoding, a token is substituted in the data stream for
the actually occurring character in an attempt to send fewer than 8 bits for each
character. The token is generated from a dynamic tabulation of character
appearance frequency. The total number of available tokens is 256, of which only
the first 32 tokens are smaller than 8 bits, so random data will gain no advantage
from this technique.

String Coding

Instead of sending each data character individually, a token for a character string
is sent. The modem adaptively builds a dictionary of string tokens according to
data that appears. Omni modems support a dictionary size up to 2K string tokens.
The input data characters are combined and checked for a matching string in the
dictionary. The token is sent for the longest matched string. Compressibility is
high if there are some regularities of character pattern in the data.

The error control and data compression option can be enabled either from the or
the terminal.
transmission of already compressed files is usual, the MNP5 data compression
process actually produces more redundant data and slows down transmission.
Setting S38b5 will disable MNP5 protocol negotiation regardless of the error
control setting.

is the default. For some applications, like BBSs, where

&K4

Hardware or Software Flow Control

Flow control determines how data will be transferred between your computer and
modem. Your modem supports two flow control methods. But regardless of
which flow control method you use, make sure your communications software is
configured to use the same flow control method that your modem is using.
Otherwise, you may experience erratic data transfer where portions of received
data are lost, or you will receive frequent errors during data transfers.

The flow control option is set by

AT&H

n as follows:

4-7

Chapter 4 - Advanced Data Communications

&H0 disables flow control
&H3 sets CTS/RTS flow control
&H4 sets XON/XOFF flow control

Hardware CTS/RTS

This is a bi-directional flow control where CTS and RTS are RS232 signals
which must be available on your computer. When the modem's transmission buffer
is almost full, the modem will drop CTS to signal the DTE that it cannot accept
any more data. Turn ON the CTS to notify the DTE that it can keep sending data to
the modem. On the computer software side, when the receiving buffer of the
software is almost full, it will drop RTS to signal the modem to stop sending data
to the DTE. Turn ON the RTS and the modem will start sending data again to the
DTE. In asynchronous full-duplex applications, the Omni 288S always responds
to the RTS signal as a flow control signal. The Omni 288S defaults automatically
to this hardware flow control setting and it is a better choice.

Software XON/XOFF

This is a bi-directional flow control. XON and XOFF character defaults are
decimals 17 and 19. These can be changed by modifying the S-Registers 31 and

32. Both the modem and the DTE will treat XOFF as a signal to stop transmitting

data, and will treat XON as a signal to restart sending data. Modems will not send
these characters received from the local DTE to the remote modem.

4-8

Chapter 5 - Synchronous Mode Operation

Chapter 5 - Sync hr onous Mode Operation

This chapter introduces you to the use of the Omni 288S for synchronous
operation. The modem can be used as a synchronous modem when it is connected
to a synchronous computer or terminal. It is of course necessary to make sure that
the remote modem and system are also set to synchronous. Synchronous operation
applies to all of the non-FSK modes the modem is supplied with. Before
synchronous transfers are started, some initial settings should be made.

V.25bis Command Set

To enable V.25bis commands use the AT*I1 command.
For synchronous applications, the modem is permanently set in normal situations

for use with one application. Save the desired settings in the power-on profile,
and the modem will be initialized to synchronous mode (&M3) with V.25bis
command enabled (*I1) when turned it is turned on.

A special command RST is provided to get the modem back to asynchronous AT
command mode from V.25bis mode. You can enter this RST command in either
synchronous or asynchronous V.25bis mode.

Syntax Command with Parameters* Description

CRN CRN <dialstring>** Call request with number provided.
CRS CRS n Call request with number from

memory, 0 # n # 49;
n is the memory location.

PRN PRN n; <number> Saves <number> to address n

(0 # n #49).
RLN RLN*** Requests list of all stored numbers.
DIC DIC Ignores incoming call.
CIC CIC Accepts incoming call.
CFI CFI XX Call failure indication:

ET Engaged Tone.

NS Number is not stored.

RT RING Tone.

AB Abort Call.

NT Answer Tone is not detected.
INC INC Incoming call.
VAL VAL Valid.
INV INV Invalid.
LSN LSN n; <number> List of stored numbers.

(Response to RLN)
RST RST Changes to the asynchronous

AT command mode.

5-1

Chapter 5 - Synchronous Mode Operation

Clock Options

Synchronous data must be transmitted and received with a common timing clock.
This timing clock is used to transmit data from the DTE to the modem which
modulates the data according to this clock. The receiving modem recovers the
clock and data from the carrier and sends the data to the receiving DTE along
with the clock. There are three types of transmission synchronous clock sources to
choose from:

1. The internal clock is the one that suits most applications and is the default; in

this case, the clock signal is generated by the sending modem.

2. The slave clock is used when in remote digital loopback mode.

3. The external clock is a signal generated by the sending DTE.

INTERNAL AT&X0 The modem provides the clock and sends it to the

DTE. Adaptive rate can be used. (Default)

EXTERNAL AT&X1 The DTE provides the clock and sends it to the

modem. Must use auto-retrain, cannot use adaptive
rate.

SLAVE AT&X2 Recovered receiver clock serves as transmission

clock.

RTS Options

There are two RTS options. The choice depends on application and host/terminal
requirements. In asynchronous mode RTS is used as a hardware flow control
signal.

IGNORED AT&R1 RTS is ignored; always assumed to be ON.

(Default)

CTS TRACKS RTS AT&R0 Delay before CTS responds to RTS's

change. The delay is set in the S26 register.

Command State Options

For synchronous data communication, there are two options you can choose from
to define how the modem will operate in the command state.

SYNC DATA AT&M1 The modem accepts asynchronous command in

command state, but exchanges data
synchronously in data state.

SYNC AT&M3 The modem accepts synchronous command

(V.25bis) and exchanges data synchronously
with a remote modem.

5-2

Chapter 5 - Synchronous Mode Operation

You can always use the panel operation to control and configure the modem and
use the manual dial and answer to operate the modem.

Dialing from Synchronous Mode

1. Dial from the terminal using asynchronous commands. Set &M1 and use

asynchronous AT commands to dial the number. Once the modem is
connected, the modem will enter synchronous operation.

2. Dial through the computer using V.25bis commands. Some communication

software packages on synchronous computers can dial using V.25bis
synchronous commands. In this case, set &M3 and *I1 and the modem will
accept V.25bis commands and make a synchronous connection.

3. Using DTR to dial a stored number in synchronous mode. Store the

telephone number from the front panel STORE NUMBER menu or by the
asynchronous command &Zn=. Use the DEFAULT DIAL parameter menu or

*Dn command to select the default dial pointer. Set &D1 and either &M1 or
&M3, then raise DTR from your terminal or communication software. The

modem will dial the default stored number. After the modem is connected, the
modem will enter synchronous operation.

With S35b4 set, pressing the DATA/VOICE switch will also cause dialing of

the default number.

4. Manual dial. Set the modem to synchronous mode (&M1 or &M3), then dial
a number from a telephone set. When you hear the answer tone, type ATD (if
&M1 is set). The modem will go into synchronous operation after connection.

Answering from Synchronous Mode

Auto-Answer

Set the modem to synchronous mode. Set the S-register S0 to equal the number of
rings before auto-answer occurs. Set it from the terminal (if &M1 is set) using the
asynchronous AT command, or select the STATUS REGISTER menu to change
the S0 value.

Manual Answer

Type ATA from the terminal (if &M1 is set).

5-3

Chapter 6 - Leased Line Operation

Chapter 6 - Leased Line Operation

A leased line is a permanent telephone line connection between two fixed points.
It can be dedicated copper wires or a leased telephone circuit from the telephone
company. 4-wire leased lines use one pair of wires to transmit data and a second
pair to receive. 2-wire leased lines transmit and receive on the same pair of
wires. The Omni 288S supports only 2-wire leased lines.

Connecting to a 2-Wire Leased Line

The Omni 288S is equipped with a phone jack for dial-up line connections.
Connections can also be made to a 2-wire leased line using the same jack.

Line Type Setting

AT-Command Description

AT&L1 The modem is connected to a 2-wire leased

line; the line plug should be plugged into the
jack assigned LEASED LINE on the rear
panel.

For the normal dial-up line only models, only 2-wire leased lines can be used and
the same phone jack is used for both dial-up and leased-line connections. The dial
backup feature is not available in this case.

Power Level Setting

The Omni 288S’s leased-line mode transmission power level can be adjusted
from 0 dBm to -27 dBm in 1 dBm increments. If a dial-up model is used for 2­wire leased-line connection, the transmission power is limited to -3 dBm.

AT-Command Description

AT*P0
AT*P15

The default is -9 dBm. The adjustable range
is from 0 to -15 dBm, effective in leased­line operation only. If bit 3 of S35 is set,
this range will change to -12 to -27 dBm.

Leased Line Handshaking

In a typical dial-up connection, the originating modem dials the number and waits
for the answering modem's carrier signal. The answering modem can be
commanded to either answer the call immediately, or after a specified number of
rings.

In a leased-line connection, the communication circuit between two modems is
always present. Dialing and waiting for rings does not occur in this situation. If
these two modems want to establish a data link, one must be designated as the

6-1

Chapter 6 - Leased Line Operation

originator and the other as the answerer. You can set this manually or
automatically.

Manual Connect

Set the modem to leased-line mode. Type the asynchronous command
originating modem and
originate or answer mode.

to the answering. Use

ATA

AT*Mn

or set

S14b0

ATD

to select

to the

Auto Handshake

If you want handshaking to occur automatically upon power-up, you have to save
the leased-line configuration to the power-on profile. How to designate a profile
to be a power-on profile is described in Chapter 3. Please remember to set the
handshake mode before you save the configuration. Be sure that one modem is set
to originate mode and the other to answer mode.

AT-Command Description

AT*M0 When operating over a leased line, modem

will handshake in originate mode. (Default)

AT*M1 When operating over a leased line, modem

will handshake in answer mode.

Terminating a Leased Line Connection

Pressing the
on/off the connected leased line.

DATA/VOICE

switch on the Omni 288S will switch the modem

6-2

Chapter 7 - Cellular Mode Operation

Chapter 7 - Cellular Mode Operation

The Omni 288S is equipped with a special cellular communication mode which
enables the modem to perform reliable high speed data transmissions over
cellular phone links. Although all ZyXEL modems can provide the cellular mode,
the ZyXEL U-1496P portable modem is specially designed for mobile use. We
have nick-named the ZyXEL cellular mode as ZyCellular. This chapter not only
explains the ZyCellular mode, but also gives background information on cellular
data communications.

Cellular Phone Systems

We are referring here exclusively to the analog cellular phone system. It is called
AMPS (Advanced Mobile Phone Service) in North America. The cellular phone
system got its name by dividing its covered area into many small cells. Each cell
has a cell site radio station maintaining a radio link with every cellular phone that
is in use in the cell. If a cellular phone moves out of one cell's boundary and goes
into another cell, it will be instructed to switch its radio link to the new cell using
a new frequency channel. This is called cell hand-off.

By limiting the radio transmission power in each cell's radio communication, it
will not interfere with a distant cell's radio communication using the same
frequency. Frequency reuse is the principle of cellular phone systems to increase
the number of radio channels available.

Cellular Impairments

A common problem in cellular communication is cell hand-off. In the process of
cell hand-off, the radio link, hence the modem carrier, will be interrupted for 0.2
second to 1.2 seconds. A normal modem will respond with retrain which takes
about 10 seconds or may even hang up.

A cellular phone may be instructed to change its power depending on its distance
from the cell site station. The radio link will be interrupted for about 0.2 second.
An effect similar to cell hand-off will .

A particularly difficult cellular impairment for data communication is called
multi-path fading. A cellular phone receives the cell site station's radio signal
through many indirectly reflected paths. Due to the phase difference of the arriving
signals caused by the signals taking different paths, the combined signal,
depending on location, may be strong, weak or totally faded. A moving cellular
phone will experience a periodical signal weakness. This is called multi-path
fading. Fading will cause data errors because the carrier is lost due to fading.

The analog cellular phone system was designed for voice communications. It
employs companding (concatenated from compressing and expanding; it makes
small signals better at the sacrifice of large signals) and pre-emphasis which are

7-1

Chapter 7 - Cellular Mode Operation

good for voice, but not suitable for a modem signal. Modem signals, if too strong,
may saturate the cellular link and cause distortion. Modem signal power that is
too weak will result in lower signal-to-noise ratio at the receiving end. There is
an optimum power in cellular data communications, but it is different in each
case.

Cellular Modems and ZyCellular Technology

A truly cellular modem must handle the cellular impairments and maintain a
reliable data link with reasonable data throughput through a cellular channel.
Some modems claiming to be "cellular” lack most of these capabilities.

A link-layer-only protocol does not do anything to enhance modem data pump
performance or physical communication robustness. It does not help much to
handle cellular impairments.

ZyXEL developed special technologies for cellular data communications to
provide reliable, high throughput data links over a cellular channel. We call these
technologies ZyCellular. ZyCellular technologies specifically improve the
modem data pump's performance with respect to cellular impairments.

ZyCellular Modes

In addition to normal modem, fax, and voice operation modes, the following
cellular modes are available in the Omni 288S:

Mode Speed

Multi-Auto V.34/ZyX modes/V.32bis/V.32/V.22bis/G3 FAX/Cellular
CELL 14400 14400/12000/9600/7200/4800
CELL 12000 12000/9600/7200/4800
CELL 9600 9600/7200/4800
CELL 7200 7200/4800
CELL 4800T 4800

CELL 14400

will connect with another modem using cellular mode at a speed of
up to 14400 bps. It will also connect with another V.32bis/V.32 modem. The
actual speed depends on the line condition. The modem will automatically fall­back or fall-forward within its speed range.

CELL 12000, CELL 9600,

and

CELL 7200

limit the maximum speed to 12000

bps, 9600 bps, and 7200 bps, respectively.

CELL 4800T

uses a trellis coded modulation at 4800 bps speed. It has a better

performance than the uncoded V.32 4800 bps mode.
The modem will automatically and dynamically select and adjust to the best speed

and mode in which to operate. Selecting one of the above cellular modes only
limits the maximum speed at which the modem will operate.

7-2

Chapter 7 - Cellular Mode Operation

The MULTI-AUTO mode will automatically adapt to the other modem's
capability, and will request and connect the appropriate mode. If both sides have
cellular mode capability and at least one side is using a cellular phone, using
MULTI-AUTO to make or answer a data call will result in a cellular mode
connection. MULTI-AUTO is the default mode.

Cellular Mode Usage

Usage of the cellular mode is recommended when using a cellular link for modem
connections. It can also be used other bad line conditions such as a line with
frequent large impulse noise. ZyCellular mode is more noise resistant, impairment
resistant, and error resistant.

It is simple to use the ZyCellular mode. Everything is determined automatically by
the modem. The user only needs to set S-register S49 bit 7 and leave the modem
on MULTI-AUTO. The modem takes care of everything else.

S49b7 tells the modem where it is installed. If S49.7=0, the modem is installed in
an office connected to a normal telephone line; if S49.7=1, it means the modem is
a mobile unit connected to a cellular phone. When a ZyCellular modem calls or
answers another modem, it will indicate its cellular capability and whether it is
using a cellular phone. If both sides have the ZyCellular capability and at least
one side is using a cellular phone, the connection will automatically be a cellular
mode connection such as it would be if it were using CELL 14400 mode. If one
side is a normal non-cellular modem, the connection will automatically be a
normal modem mode.

If manual power setting is desired, set S43.2=1 to disable power adjustment
and use S49 bits 0-3 to set power -9 to -24 dBm.

If a cellular mode connection is desired, set S43.3=0 to enable the cellular mode
connection. The default for this option is to be disabled (S43.3=1).

You can also send and receive faxes on cellular links by setting S49.7=1 on the
ZyCellular modem that is using a cellular phone. Now your modem can send and
receive faxes to and from fax machines and other fax modems.

Cellular Modem Installation Examples

The most difficult part of cellular modem installation is connecting the modem to
the cellular phone. There is no standard on the interface and connector type that a
cellular phone should use or provide. Every cellular phone maker has its own
interface design. There isn't a standard way to connect a modem to a different
brand of cellular phone. Some vendors have made a specific adapter for each
model of cellular phone that will convert a specific cellular phone's interface to a
standard telephone company's 2-wire phone interface. A cellular modem can
connect to a cellular phone such an adapter.

7-3

Chapter 7 - Cellular Mode Operation

If you are using a cellular phone data interface adapter, the following figures
illustrate three installation examples. The figures are illustrated with a U-1496P
model. You can use the Omni 288S, in the same way.

The following is an example of a mobile phone that has a handset cradle and a
separate transceiver and handset.

The following is an example of a mobile phone that has a separate transceiver and
handset.

The following is an example of a one-piece hand-held mobile phone.

7-4

Chapter 7 - Cellular Mode Operation

Some newer cellular models, particularly the hand-held ones, have an audio jack
that can connect the cellular phone's audio input/output to an outside headphone­microphone set. A simple adapter cable can be used to connect the RJ11 modem's
2-wire interface to this cellular phone's audio jack. In this case, you need to
manually dial or answer a call using the cellular phone to establish a phone
connection and then manually make the modem go on-line using the ATD or ATA
command.

7-5

Chapter 7 - Cellular Mode Operation

Office Installation

Naturally, you can install the Omni 288S in an office environment, as with all the
other ZyXEL models.

7-6

Chapter 8 - Special Functions

Chapter 8 - Spec ial Functi ons

This chapter describes the special features of the Omni 288S, and offers
instructions on how each is used.

Security Functions

The Omni 288S provides a security function that prevents unauthorized users from
making connections. Two types of security functions are provided.

 Type 1 security is used when the remote modem is also a ZyXEL modem.
 Type 2 security is used when the remote modem is any other brand.

The type 1 connection, the dial-in (remote) modem will send in its supervisor
password for checking at the initial connection , and the local modem will check
this password against its pre-stored acceptable password list.

The type 2 connection, the remote terminal will be prompted to enter the
password at the initial connection and the local modem will do the password
checking.

Levels of Security

Two levels of security are provided:

 With level 1 security, the local modem will maintain the connection if the

password is OK, otherwise the line disconnected.

 With level 2 security, dial back the phone number corresponding to the dial-

in password. The line simply disconnected if the password does not match.

User Passwords

50 user passwords may be defined. The corresponding 50 dial-back numbers are
the the modem’s 50 stored phone numbers. Any character (ASCII 0-127) can be
used in the password, the maximum password length is 8 characters.

The security functions are only accessible through AT commands in terminal
mode. Any access attempt will result in the modem’s prompting to enter the
supervisor password the attempt will be rejected if the entered password is not
correct. The default supervisor password is ZyXEL when the modem is shipped
from the factory. This supervisor password is also the password sent for
automatic password checking in a type 1 connection. To modify the supervisor
password, use AT*HS.

You will be asked for the original password and a new password and then to re­enter the new password for verification. For example:

Password: (Enter supervisor password)

8-1

Chapter 8 - Special Functions

********
Password: (Enter new supervisor password)
********
Verify: (Enter the new supervisor password again)
********
OK

The command AT*Hn will modify the nth user password. You will be prompted
to enter the supervisor password first and then be prompted to enter the nth user
password.

The command AT*V will list the 50 user passwords and the supervisor password
on the screen for viewing. Again, you will be prompted to enter the supervisor
password first.

The following commands will enable different types and levels of security:

Command Function
*G0
*G1
*G2

*G3
*G4

*G5

Disable security function.
Enable type 1 and level 1 security, with password check.
Enable type 1 and level 2 security, with password check
and callback.
Enable type 2 and level 1 security, with password check.
Enable type 2 and level 2 security, with password check
and callback.
Enable type 2 and level 2 security, with password check
and callback, remote site enters the callback number.

Note: Before t he security type or l evel changed, the modem requires

the supervisor password.

For type 2 security, the remote site will be prompted to enter the user password.
A maximum of 3 tries in 40 seconds is allowed. If a correct password is not
entered within this time limit the line will be disconnected. If the remote site is to
enter the callback number it will be prompted to do so.

Remote Configuration

Remote configuration on the Omni 288S is provided as a profile by profile
batch mode. When on-line, the remote modem’s current configuration or one of its
profiles can be read into one of the local modem’s user profiles. This profile is
modified locally and the line can be disconnected during this time.

8-2

Chapter 8 - Special Functions

Local profile modification is done by loading this profile as the active settings
and then modifying and saving the active settings back to the profile. Then the
connection is reestablished and the profile transmitted to the remote modem.

Reading a remote profile b into a local profile a is acheived by the command:

AT*Rab

a=0-3
b=0-3
b=4
b=5

Return the modems to on-line status again. The local modem can upload (write)
its profile to the remote modem’s profile and have the remote modem reset from
the new profile. This is done with the command:

AT*Wab

a=0-3
a=4
a=5

b=0-3

Local user profile number
Remote user profile number
Remote active configuration
Remote factory default

Local user profile number
Local active configuration
Local factory default

Remote user profile number

The remote profile read and write commands - *Rab and *Wab - only work in
the on-line condition. The connection speed and mode do not matter. The remote
modem must be set to accept remote configuration by executing the AT*F1
command. The AT*F0 command will set the modem up to deny remote
configuration requests. Because the modem uses the remote digital loopback mode
to request remote configuration information, the remote digital loopback request
must also be granted (AT&T4) on the remote modem to accept the remote
configuration request.

Batch mode remote configuration is a convenient feature allowing you to pre­configure a remote modem in one of the local modem’s user profiles and send it to
the remote modem in one action. It is particularly useful when there are many
remote modems and a set of standard configurations is available so you can store
them into user profiles. You just need to configure the remote modem into one of
the standard configurations by activating the remote configuration once.

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Chapter 8 - Special Functions

Caller Number Delivery (Caller ID)

Caller Number Delivery (CND), commonly called Caller ID, is a new kind of
phone service that may be offered by your local phone company. Check your
phone company for availability. You must subscribe to it and usually pay an
additional monthly service charge this service.

With CND service, the phone company’s central office will send the coded caller
information to the called station. This information is sent once between the first
and second. The Omni 288S modem can decode this caller information and
present it to the connected computer/terminal during the second ring period as part
of the call progress ring message. The modem will also report the Caller ID
information if asked by the command AT*T.

There are two kinds of caller information message formats sent by the phone
company.

 One is the single message format which includes date, time, and caller ID
 The other is the multiple message format which also includes the caller name

as registered with the phone company.

The command ATS40.2=n is used to enable (n=1) or disable (n=0) the Caller ID
detection function. The default is disabled. Enable it only when you have this
service and want to enable its detection.

Note: The Caller ID message may cause some communication

software that is not expecting it to become confused. If you
plan to use the Caller ID feature, be sure you are using
software that supports it (such as ZFAX).

In single message format, the modem will send a ring message to the terminal as
follows:

RING
TIME: <MM-DD hh:mm>
CALLER NUMBER: <CALLER_ID> or CALLER

NAME:<CALLER_NM>
RING

MM is the two-digit month message, DD is the two-digit date message, hh is the
hour and mm is the minute of the time, and CALLER_ID is the phone number of
the caller or CALLER_NM his/her name.

The following is an example of a caller ID message as it might appear on your
screen:

RING
TIME: 04-28 12:30

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Chapter 8 - Special Functions

CALLER NUMBER: 7135551414 or CALLER NAME: Jack
Smith

RING

In the multiple message format, if the caller’s number and name are available, the
ring message will display both:

RING
TIME: MM-DD hh:mm
CALLER NUMBER: <Caller_ID>
CALLER NAME: <Caller_Name>
RING

Here is an example:

RING
TIME: 04-28 12:30
CALLER NUMBER: 7135551414
CALLER NAME: Jack Smith
RING

If the caller number and name are not available, the ring message will appear as
follows:

RING
TIME: 04-28 12:30
REASON FOR NO NUMBER: OUT_OF_AREA
REASON FOR NO NAME: PRIVACY
RING

The last CND message that the modem received can be displayed by using the
AT*T command.

Setting S48.0=1 will cause the modem to report CND information in its ASCII
coded hexadecimal raw data format. The DTE software is responsible for
explaining the data.

Notes: Please refer to the Bellcore Technical Advisory document AT-

NWT-000030 for the exact dat a format. The above Caller ID
scheme applies to the North America area. Different countries
may employ different Caller ID schemes, check if the scheme
used in your count ry is supported before using the Caller ID

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Chapter 8 - Special Functions

feature. For most other Caller ID schemes, only the Caller
telephone number is provided.

Distinctive Ring

Distinctive Ring is a phone service that may be offered by your phone company.
Check your phone company for availability. With this service, you can have
several phone numbers assigned to the same phone line. The phone company will
send a different type of ring signal for each phone number being called. The
subscriber can distinguish which number is called by which type of ring is
received.

A simple use of this feature is that you can have three numbers on the same line
and you can list the three numbers for voice, data, and fax, respectively. You can
then have your fax machine answer only the ring corresponding to the fax number
and have your modem answer only the ring corresponding to the data number. The
voice call will not be answered by either fax machine or data modem and it will
only be answered when someone picks up the phone. Or you can have the
answering machine answer only the voice ring. A more complicated use is that
you can have one number for multiple uses, such as one number for both data and
fax.

A ring signal is a composition of repeated on and off states. Different types of
rings usually correspond to different compositions of the “ON” part (cadence) of
the ring. The Omni 288S modem can distinguish up to four types of ring signals
and can be commanded to answer or not answer any one of these four types of
ring signals. Following is a list of these four types of ring signals. These are the
ring types used in the USA. The difference among the ring types is the two­second ON part of the ring signal. It comprises a long, double short, or triple short
ring.

S-register S40 bits 3-6 are used for distinctive ring control. Each bit controls the
answering of a particular ring type. Setting a bit to “1” (on) enables answering,
setting it to “0” (off) rejects the ring. Note that the ring may still be heard even if
it is not counted as an accepted ring by the modem.

The control relationships between bits 3-6 in register S40 and the different ring
types are:

Type Bit (on) Ring Sequence

1 3 1.2s or 2s on; 4s off
2 4 0.8s on, 0.4s off, 0.8s on; 4s off
3 5 0.4s on, 0.2s off, 0.4s on, 0.2s off, 0.8s on; 4s off
4 6 0.3s on, 0.2s off, 1s on, 0.2s off, 0.3s on; 4s off

Note: If all of these bits are "0" (off ), any ri ng with a dur ation l onger

than 100 ms will be accepted. Use this default if you do not
have distinctive ring service.

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Chapter 8 - Special Functions

If more than one type of Distinctive Ring is turned on, RING n will be reported
for an incoming ring signal where n is the ring type number.

Note: Countri es other than t he U.S. may have different specifications

for different ring types. The manufacturer may append other
sets of ring type specifications to suit each country's needs.

Extended Distinctive Ring (EDR)

Extended Distinctive Ring (EDR) is a special feature designed for single
telephone line home use to receive fax or data calls without interfering with
regular voice calls. Most users, when they install a fax/modem at home, won’t
subscribe to an extra telephone line for occasional fax or data calls; however,
fax/data calls do come in from time to time.

If a user lets the fax/data software application answer, voice calls will be missed.
On the other hand, if a human being or an answering machine answers, fax or data
calls may either be missed or the person who answers the call has to go through
some procedures to get this call connected to the proper application. Either way
is not desirable.

Once enabled with the proper settings, EDR can:

1. Detect the data/fax CNG tone without physically answering the call. After a

CNG tone is detected, the modem will report RING or RING n to the
application software. The software can cause the modem to answer the call.

2. Detect several DTMF tones without physically answering the call. The

DTMF tones, once detected by the modem, will be reported as RING or
RING n to the software application.

With these two functions, the Omni 288S can be installed with an answering
machine or voice telephone set at home. In most cases, the modem should not be
set to answer regular rings, nor to report them. Thus, the software will not instruct
the modem to answer the call when phone rings. When a call comes in, the
answering machine will answer the phone and play a voice message. At this
moment, the modem, having detected the ring signal is gone, will start to listen to
the line for CNG tone or DTMF tones.

If the remote caller is an unattended fax machine, it will send a CNG tone for a
period of time. The modem will detect the CNG tone and report RING to the
software immediately. The software application can then issue commands to
answer the call and receive the fax. If the remote caller is using a fax phone which
does not send out a CNG tone and is waiting for a fax answer tone in order to
press the START button, the caller can press a designated DTMF tone, which
will activate the modem to report and subsequently be ordered to answer the fax
call.

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Chapter 8 - Special Functions

Setting Up EDR

The new EDR can be used at home where multiple phones are installed in
parallel. Once this function is enabled, the modem will go into EDR mode after
the ring disappears, and it will be able to detect the data/fax CNG tone and
DTMF tones, and report them as different types of rings. The EDR settings are
defined in S-register S51.

S51 Bit-mapped register: (default: 0)

Bits Bin. Dec. Description

(7,6) 00 0 Disable data CNG tone detection (default)

01 64 Report RING for data CNG tone
10 128 Report RING 1 for data CNG tone
11 192 Report RING 3 for data CNG tone

(5,4) 00 0 Disable Fax-CNG tone detection (default)

01 16 Report RING for fax CNG tone
10 32 Report RING 1 for fax CNG tone
110 48 Report RING 2 for fax CNG tone

(3,2) 00 0 Disable DTMF tone detection (default)

01 4 Report RING for a DTMF tone
10 8 Report RING <DTMF> for a DTMF tone
11 12 Reserved

(1,0) 00 0 Disable EDR (default)

01 1 Report RING twice
10 2 Report RING four times
11 3 Report RING six times

EDR detection (either CNG or DTMF tones) will be disabled once it . However,
a customer’s program might not answer because the setting of the software may
require multiple rings to answer. S51 bits 0-1 control the number of rings that the
modem will report once the CNG or DTMF tone is detected.

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Chapter 8 - Special Functions

The timing relationship between the Caller ID (if enabled), EDR, and ring
detection is as follows:

ring1 ring2 ring3
***--------***--------***-----------------------------­ 3sec 3s 3s 3s S7 timeout
+------+---+------+---+------+---+-------------+---­ CID/EDR RD EDR RD EDR RD EDR RD

=Caller ID task

CID

=Ring Detection task

RD

EDR

=EDR task

Note: During the EDR period, any AT command will disable the EDR

function.

EDR Application Example

If we use ZFAX as our fax receiving application and we don’t want it to answer
the call unless it is a fax call, the way to set it up would be:

1. Set ZFAX to answer on 2 rings.

2. Set

3. Set

4. Set

Save the settings in a profile and reset the modem with

S51.0=1

to enable EDR and report RING twice. The modem will not
report a normal RING and ZFAX will not answer a call unless EDR RING
is reported.

S51.4=1
S51.2=1

to enable fax CNG tone detection. It is reported as RING.

to enable DTMF tone detection. It is reported as RING. If the
remote fax machine does not generate the CNG tone, ask a fax caller through
your answering machine message to press “*” (or any other DTMF key) if he
or she wants to send a fax.

AT&WZ

.

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Chapter 9 - Fax Operation

Chapter 9 - Fax Operation

The Omni 288S can be used as a fax machine, and this chapter explains how. In
the sections below, we will describe how the modem works as a fax machine, the
ITU-T T.30 fax protocol, the Class 1, 2, and 2.0 fax commands and ZyXEL
extended fax AT commands. Also covered are the status report result codes, the
flow control protocol associated with ZyXEL fax AT commands, and some
specific fax applications. The instructions for using the included
modem/fax/voice utility program are included on the software disk. Some
distributors and dealers also include other software with the Omni 288S. For
help with such software, refer to the documentation that came with it.

Fax Basics

Fax is the abbreviation for facsimile. There are four major parts in a facsimile
machine: the scanner, encoding and decoding device, modem, and printer. Before
a page can be sent, it is first scanned. The bit-mapped data is encoded with data
compression and is then transmitted across the phone line by an internal modem
module. The remote facsimile receives the data with its internal modem, decodes
it back to bit-mapped image data, and prints it on paper.

Fax Branding:

any person to use a computer or other electronic device to send any message via a
telephone or fax machine unless such message clearly contains in a margin at the top or
bottom of each transmitted page or on the first page of the transmission, the date and time
it is sent and an identification of the business or other entity, or individual sending the
message and the telephone number of the sending machine or such business, or entity, or
individual. In order to program this information into the fax function of your modem,
please refer to the documentation of the fax software you will be using.

The Telephone Consumer Protection Act of 1991 makes it unlawful for

Modem as Fax Machine

Modems can also be designed to include a fax transmitting and receiving function
similar to a fax card. Since the modem's interface with the computer is the
standard serial RS-232 interface, this interface is used for both modem and fax
operations. Fax image coding and decoding must be done in the computer.
Modem/Fax, also called fax/modem, can be either an external stand-alone unit or
a plug-in card. External stand-alone units can be connected to any computer with a
standard RS-232 serial port.

The Omni 288S supports Group 3 send and receive facsimile functions. For
normal fax operation, you must connect the modem to a computer, usually a PC.
The computer serves as the input/output device for the fax function. The RS-232
serial connection or the ZyXEL serial port interface connects the Omni 288S to
the computer. The Omni 288S uses the same interface for both data and fax
applications. In fax operations, the modem performs protocol handshaking and

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Chapter 9 - Fax Operation

image data transfer. The computer handles image data creation, capturing,
conversion, compression, decompression, retrieving, and storing.

ITU-T T.30 Fax Protocol

The ITU-T T.30 fax protocol is known as the G3 fax handshake signals and
procedures. The modem takes full control of this protocol - initiating and
terminating fax calls, managing the communication session, and transporting the
image data. Therefore, the modem relieves the computer fax software of the T.30
protocol handling.

The Omni 288S allows for fax speeds up to 14400 bps when transmitting to a fax
machine which complies with the G3 fax standard. Speeds will fall back to
12000, 9600, or 7200 bps in poor line conditions. When connecting to a non-G3
fax device, the Omni 288S allows for fax speeds up to 9600 bps and will
automatically fall back to 7200, 4800, and 2400 bps if the line quality is poor.

Fax Command sets

The Omni 288S supports four command sets for fax operation:

 Class 1 command set
 TIA PN-2388 Class 2 command set
 TIA 592 Class 2.0 command set
 ZyXEL Extended Fax AT command set

Defining the Fax Command Sets

The EIA Class 1 and Class 2 fax commands are a set of AT fax commands
defined by EIA/TIA (Telecommunications Industry Association) for controlling
fax/modems from a computer through the serial RS-232 interface. All fax/modems
and fax software supporting this standard will be compatible with each other.

Class 1 commands control how the modem does on-line negotiation while Class 2
commands allow the modem to do many negotiations at once. The Class 1
protocol uses the modem to transmit fax data only. The complete organizational
overhead for this protocol is handled by the connected computer. The Class 1
command set is also called the TIA-578 standard.

Several revisions of the class 2 standard exist. Implementations conforming to
different revisions may not work together. A formally approved version is the
Class 2.0 command set, also called the TIA-592 standard.

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Chapter 9 - Fax Operation

Class 1 Command Set

Command Value Description

+FCLASS=n Service class selection

n=0 Set to Data mode
n=1 Set to Class 1 mode
n=2 Set to Class 2 mode
n=2.0 Set to Class 2.0 mode
n=6 Set to ZFAX mode
n=8 Set to Voice mode

Note: If S57.4=0 (default), the re sponse t o the +FCLASS=? command

will not report Class 1 capability. This is due to the fact that
some fax software packages may get confused by this response.

Command Value Description

+FTS=n 0-255 Stop transmission and pause, in 10 ms units.
+FRS=n 0-255 Wait for silence, in 10 ms units.
+FTM=<MOD> Transmit data with <MOD> carrier.
+FRM=<MOD> Receive data with <MOD> carrier.
+FTH=<MOD> Transmit HDLC data with <MOD> carrier.
+FRH=<MOD> Receive HDLC data with <MOD> carrier.

The <MOD> parameter for the preceding commands take the following values:

Value Modulation Speed Requirements

3 V.21 ch. 2 300 required for FTH & FRH

+FTH and +FRH support value 3 (V.21 ch. 2 / 300 bps) only.

24 V.27ter 2400 required for FTM & FRM
48 V.27ter 4800 required for FTM & FRM
72 V.29 7200 required for FTM & FRM
73 V.17 7200 required for FTM & FRM
74 V.17 w/st 7200 required for FTM & FRM
96 V.29 9600 required for FTM & FRM
97 V.17 9600 required for FTM & FRM
98 V.17 w/st 9600 required for FTM & FRM
121 V.17 12000 required for FTM & FRM
122 V.17 w/st 12000 required for FTM & FRM
145 V.17 14400 required for FTM & FRM
146 V.17 w/st 14400 required for FTM & FRM

* w/st means with V.17 short training

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Chapter 9 - Fax Operation

Class 2 Command Set

The following Class 2 commands are supported and implemented per TIA
PN2388 (8/20/90).

Command Syntax Description

+<command>=<value> Execute a command or set a parameter.
+<command>=? Read permissible settings.
+<command>? Read current setting.

Supported Commands (per TIA PN2388 8/20/90)

Command Value Description

+FAA=n Auto-answer mode parameter:

n=0 Answer as set by +FCLASS.
n=1 DCE answers and auto-determines type.

+FBADLIN=

<value>

+FBADMUL=

<value>

+FBOR=n Phase C data bit order:

+FBUF? Buffer size; read only parameter:

+FCIG="string" Local fax station ID string, for polling Rx.
+FCLASS=n Service class selection: Refer to +FCLASS

+FCON DCE responds fax connection .
+FCQ=n Copy quality check capability parameter

+FCR=n "Capability to receive" parameter

0-255 Bad line threshold (number of consecutive

bad lines for a bad page parameter):
Determine if Copy Quality OK on the T.30
flow chart . <value>=0 to 255; a value of 0
implies that error checking is disabled.

0-255 Error threshold multiplier:

Determine if "Copy Quality OK" on the T.30
flow chart . <value>=0 to 255; a value of 0
implies that error checking is disabled.

n=0 Select direct bit order.
n=1 Select reversed bit order in receiving mode

for phase C data.

Allow DTE to determine the characteristics
of the DCE’s buffer size.

Class 1 command in previous section.

n=0 No copy quality check capability.
n=1 Only check 1D phase C data.
n=2 Check both 1D and 2D phase C data.

n=0 DCE will not receive message data or poll a

remote device.

n=1 DCE receives message data or polls a remote

device.

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Chapter 9 - Fax Operation

Command Value Description

+FCTCRTY=

<value>

+FDCC=vr,br,wd,ln,
df,ec,bf,st

+FDCS=vr,br,wd,ln,
df,ec,bf,st
+FDIS=vr,br,wd,ln,
df,ec,bf,st

0-255 ECM retry count; in Error Mode only:

The sender will try to send a partial page 4
times. <value>=0 to 255; units of 4 retries. If
the Continue To Correct (CTC) count is 0, it
will not make any further attempts.
DCE capabilities parameters.

vr=0 Vertical resolution: Normal; 98 lpi.
vr=1 Vertical resolution: Fine; 196 lpi.
br=0 Bit rate: 2400 bit/s; V.27ter.
br=1 Bit rate: 4800 bit/s; V.27ter.
br=2 Bit rate: 7200 bit/s; V.29 or V.17.
br=3 Bit rate: 9600 bit/s; V.29 or V.17.
br=4 Bit rate: 12000 bit/s; V.17.
br=5 Bit rate: 14400 bit/s; V.17.
wd=0 Page width: 1728 pixels in 215mm.
wd=1 Page width: 2048 pixels in 255mm.
wd=2 Page width: 2432 pixels in 303mm.
ln=0 Page length: A4; 297mm.
ln=1 Page length: B4; 364mm.
ln=2 Page length: unlimited length.
df=0 Data compression format: 1-D; modified

Huffman.

df=1 Data compression format: 2-D; modified

Read.
ec=0 Error correction disabled.
ec=1 Enable error correction mode.
bf=0 Disable binary file transfer.
st=0 Minimum scan time/line: 0 ms.
st=1 Minimum scan time/line: 5 ms.
st=2 Minimum scan time/line:10 ms (normal);

5 ms (fine).
st=3 Minimum scan time/line:10 ms.
st=4 Minimum scan time/line:20 ms (normal);

10ms (fine).
st=5 Minimum scan time/line:20 ms.
st=6 Minimum scan time/line:40 ms (normal);

20ms (fine).
st=7 Minimum scan time/line:40 ms.

Current session parameter; refer to +FDCC

command.

Current session negotiation parameter; refer

to +FDCC command.

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Chapter 9 - Fax Operation

Command Value Description

+FDR Receive phase C data command; initiates

document reception.

+FDT=df,vr,wd, ln Transmit phase C data command: release the

DCE to proceed with negotiation.

+FECM=n Error mode control:

n=0 Error mode is disabled.
n=2 Error correcting mode is enabled, handled by

the DCE alone, including buffering of partial

pages.

+FET=n End of page or document command:

n=0 More pages; same document.
n=1 End of document; another document follows.
n=2 No more pages or documents.
n=4 Procedure interrupt; another page follows.
n=5 Procedure interrupt; end of document, another

document follows.
n=6 Procedure interrupt; end of document.

+FK Regular fax abort command.
+FLID="string" Local ID string parameter.
+FLO=n Flow control options:

n=0 No flow control.
n=1 Set XON/XOFF software flow control.
n=2 Set CTS/RTS hardware flow control.

+FLPL=n Document for polling command:

n=0 The DTE has no document available for

polling.
n=1 Indicate a document available for polling.

+FMDL? Request DCE model .
+FMFR? Request DCE manufacturer .
+FMINSP=n Minimum phase C speed parameter:

n=0 2400 bps.
n=1 4800 bps.
n=2 7200 bps.
n=3 9600 bps.
n=4 12000 bps.
n=5 14400 bps.

+FPHCTO=

<value>

+FPTS=n Page transfer status

0-255 DTE Phase C response timeout:

Determine how long the DCE will wait for a

command after reaching the end of data when

transmitting in Phase C.

<value>=0 to 255; 100 ms units.

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Chapter 9 - Fax Operation

Command Value Description

n=1 Received page good.
n=2 Page bad; retrain requested.
n=3 Page good; retrain requested.
n=4 Page bad; procedure interrupt requested.
n=5 Page good; procedure interrupt requested.

+FREL=n Phase C received EOL alignment:

n=0 The EOL patterns are bit aligned as received.
n=1 The last received bits of EOL patterns are

byte aligned by the DCE, with necessary zero

fill bits inserted. Refer to TIA PN-2388 for

details.

+FREV? Request the DCE revision identification.
+FSPL=n "Enable polling" command:

n=0 Disable polling.
n=1 Enable polling.

All other +F commands are not supported, but the modem will respond OK. In
many cases this means "don't care." See PN 2388 for command details.

Class 2 Command Responses

Response Value Function and Description

+FCFR Confirmation .
+FCIG:"string" Report remote ID response CIG.
+FCON Facsimile connection response.
+FCSI:"string" Report remote ID response CSI.
+FDCS:vr,br,wd,ln,
df,ec,bf,st
+FDIS:vr,br,wd,ln,
df,ec,bf,st
+FDTC:vr,br,wd,ln,
df,ec,bf,st
+FET:n Post page message response; refer to the

+FHNG:n Call termination status response.

n=00 Normal and proper end of connection.
n=10 Transmit error on phase A hang up code.
n=20 Transmit error on phase B hang up code.
n=40 Transmit error on phase C hang up code.
n=50 Transmit error on phase D hang up code.
n=70 Receive error on phase B hang up code.
n=90 Receive error on phase C hang up code.
n=100 Receive error on phase D hang up code.

+FNSC:"HEX string" Report t he n o n-st a n d a rd facilit ies c omm and fra me.

Report session parameters response; refer to

+FDCC=.... command.

Report session negotiation parameters

response; refer to +FDCC=.... command.

Report remote capabilities response; refer to

+FDCC=.... command.

+FET=n command.

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Chapter 9 - Fax Operation

Response Value Function and Description

+FNSF:"HEX string" Report t he n o n-st a ndar d facilit ie s f rame respo n se .
+FNSS:"HEX string" Report the non-standard setup frame response.
+FPOLL Remote polling indication.
+FPTS:n Receive page transfer status response; refer to

+FPTS=n command.

+FTSI:"string" Report remote ID response TSI.
+FVOICE Transition to Voice response.

Class 2 Flow Control

Flow control is necessary to match the DTE-DCE data rate to the line signaling
rate while transmitting or receiving Group 3 (T.4) data. In Class 2 fax mode, both
hardware (RTS/CTS) and software (XON/XOFF) flow control are enabled.

Class 2.0 Command Set

Command Syntax Description

+<command>=<value> Execute a command or set a parameter.
+<command>=? Read permissible settings.
+<command>? Read the current setting.

Supported Commands

Command Value Description

+FAA=n Auto-answer mode parameter:

n=0 DCE answers as set by +FCLASS.
n=1 DC E an swers an d au t o-determines call ty pe.

+FBO=n Phase C data bit order:

n=0 Select direct bit order.
n=1 Select reversed bit order in receiving mode for

phase C data.
+FBS? Buffer size parameter read only.
+FCC=vr,br,wd,ln,

df,ec,bf,st

+FCLASS=n Service class selection. Refer to +FCLASS

+FCO DCE response fax connection made.
+FCQ=<rq>,<tq> Copy quality check capability parameter

rq=0 DCE Receive Copy Quality Checking

rq=1 DCE Receive Copy Quality Checking enabled.
rq=2 DCE Receive Copy Quality Correction

tq=0 DCE Transmit Copy Quality Checking

DCE capability parameter. R e fer t o +FD C C

com m an d in Class 2 for paramet er settin g s.

Class 1 command in previous section.

disabled.

enabled.

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Chapter 9 - Fax Operation

Command Value Description

disabled.

tq=1 DCE Transmit Copy Quality Checking

enabled.

tq=2 DCE Transmit Copy Quality Correction

enabled.
+FCR=n "Capability to receive" parameter

n=0 DCE will not receive message or poll a

remote device.

n=1 DCE receives message data or polls a remote

device
+FCT=n 0-255 DTE phase C time-out parameter. n=0-255, 1

units.
+FDR Receive phase C data command initiates

document reception
+FDT Transmit phase C data command: releases the

DCE to proceed with negotiation
+FEA=n Phase C received EOL alignment parameter

n=0 Determine that T.4 EOL patterns are bit aligned

(as received).

n=1 Determine that the last received bits of T.4

EOL patterns are byte aligned by the DCE, with

necessary zero fill bits inserted.
+FIE=n Procedure interrupt parameter

n=0 Procedure interrupt requests from the remote

station are ignored, and not reported to the

DTE.

n=1 Procedure interrupt requests from the remote

station are accepted, negotiated and reported

using the +FVO response.
+FIP Initialize facsimile parameters to factory

default.
+FIS=vr,br,wd,ln,

df,ec,bf,st

+FKS Session termination command.
+FLI="string" Local ID string parameter.
+FLO=n Flow control options:

n=0 No flow control.
n=1 Set XON/XOFF software flow control.
n=2 Set CTS/RTS hardware flow control.

+FLP=n Document for polling command:

n=0 The DTE has no document for polling.
n=1 Indicated document available for polling.

Current session parameter. r efer to +F DCC C l as s

2 com m an d in previous section param et er setting s.

9-9

Chapter 9 - Fax Operation

Command Value Description

+FMI? Request DCE manufacturer identification.
+FMM? Request DCE model identification.
+FMR? Request DCE revision identification.
+FMS=n Minimum phase C speed parameter. refer to

+FMINSP Class 2 command in previos section

for parameter settings.
+FNR=rpr, tpr,

idr, nsr

rpr=0 Receiver parameters are not reported. +FIS:

rpr=1 Receiver parameters are reported. +FIS: and

tpr=0 Transmitter Parameters are not reported. +FCS:

tpr=1 Transmitter Parameters are reported. +FCS:

idr=0 ID Strings are not reported. +FTI: +FCI: and

idr=1 ID Strings are reported. +FNF:, +FNS: and

nsr=0 Non-standard frames are not reported. +FTI:

nsr=1 Non-standard frames are reported. +FTI:,

+FNS="string" Non-standard byte string parameter.

+FPI="string" Local fax station ID string, for polling Rx.
+FPP=n Packet protocol control parameter:

n=0 Disable the DCE-DTE packet protocol.
n=1 Enable the DCE-DTE packet protocol. All

+FPR=n Serial port rate control parameter:

n=0 Automatic DTE rate detection by the DCE.
n>0 Serial rate is fixed at the value multiplied by

+FPS=n Page transfer status: refer to the +FPTS Class 2

Negotiation message reporting control

parameters:

and +FTC: response reports are suppressed.

+FTC: response reports are generated.

response reports are suppressed. (+FCS

parameter is still loaded)

response reports are generated.

+FPI: response reports are suppressed.

+FNC: response reports are generated.

+FCI: and +FPI: response reports are

suppressed.

+FCI: and +FPI: response reports are

generated.

"string": string of hexadecimal coded octets.

multi-character messages from the DCE are

sent to the DTE using a simple packet protocol

data link.

2400 bps. For example, when n=8, the DTE

rate is equal to 19200 bps (8x2400).

command in previous sections for settings.

9-10

Chapter 9 - Fax Operation

Command Value Description

+FRQ=pgl, cbl Quality thresholds parameters:

pgl=
0-64
(HEX
value)

cbl=
0-FF
(HEX

value)
+FRY=n 0-255 ECM retry value n=0-255, units of 4 retries.
+FSP=n Enable polling command:

n=0 Disable polling.

n=1 Enable polling.

Class 2.0 Command Responses

Response Value Function and Description

+FCI:"CSI ID string" Report re mot e I D resp o nse, Called S t a t i o n ID
+FCO Fax connection established response.
+FCS: vr, br, wd, ln,
df, ec, bf, st
+FET:<ppm> Post page message response:

ppm=0 Another page next, same document.
ppm=1 Another document next.
ppm=2 No more pages of documents.
ppm=3 Another page next, same document, procedure

ppm=4 Another document next, procedure interrupt

ppm=5 No more documents or pages, procedure

+FHS:<hsc> termination status:

hsc=
0-0F
hsc=
10-1F

Specify the percentage of good lines (e.g. with
negotiated number of pixels) required for a
page considered acceptable. The percentage of
good lines would be computed by the equation:
100 x (<lc> - <bl>) / <lc>
lc: total line count as reported in the +FPS:
response.
bl: bad line count as reported in the +FPS:
response.
If the resulting value is less than the value in
<pgl>, the page is unacceptable.
Specify the maximum tolerable number of
consecutive bad lines. If this value is exceeded
for a given page, the DCE shall consider the
page unacceptable.

negotiated session parameters (DCS frame
information) response. Refer to +FIS= comnd.

interrupt requested.

requested.

interrupt requested.

Call placement and termination. Refer to TIA­592 for details.
Transmit phase A and miscellaneous errors.
Refer to TIA-592 for details.

9-11

Chapter 9 - Fax Operation

Response Value Function and Description

hsc=
20-3F
hsc=
40-4F
hsc=
50-6F
hsc=
70-8F
hsc=
90-9F
hsc=

A0-BF
+FIS:vr, br, wd, ln
df, ec, bf, st

+FNC:
"NSC FIF string"
+FNF:
"NSF FIF string"
+FNS:
"NSS FIF string"
+FPI:
"CIG ID string"
+FPO Remote polling indication.
+FPS:ppr, lc, blc,
cblc, lbc

ppr=1 Received page good.

ppr=2 Page bad; retrain requested.

ppr=3 Page good; retrain requested.

ppr=4 Page good; remote request for procedure

ppr=5 Page bad; retrain requested; remote request

+FTC: vr, br, wd, ln,
df, ec, bf, st

Transmit phase B hang up codes. Refer to
TIA-592 for details.
Transmit phase C hang up codes. Refer to
TIA-592 for details.
Transmit phase D hang up codes. Refer to
TIA-592 for details.
Receive phase B hang up codes. Refer to TIA­592 for details.
Receive phase C hang up codes. Refer to TIA­592 for details.
Receive phase D hang up codes. Refer to TIA­592 for details.
emote fax station capabilities (DIS frame
information) response refer to +FIS=...
command for a description of sub-parameters.
Report NSC (non-standard Commands) frame

Report NSF (non-standard Facilities) frame.

Report NSS (non-standard Setup) frame.

Report remote ID response-Polling Station ID
(CIG).

.30 phase C page reception response:

interrupt accepted.

for procedure interrupt accepted.
The receiving DCE may count <lc>, <blc>,
<cblc> and <lbc> due to DCE buffer overflow
and report them:
lc: line count
blc: bad line count
cblc: maximum consecutive bad line count
lbc: lost byte count
emote fax station capabilities (DCT frame
information) response refer to +FIS=...
command for the description of sub-

9-12

Chapter 9 - Fax Operation

Response Value Function and Description

parameters.
+FTI:
"TSI ID string"
+FVO Report transition to voice.

Remote ID response-Transmit Station ID

(TSI).

Extended Fax AT Command Set

Extended Fax AT Commands are unique to ZyXEL modems. The computer
controls the modem through a set of extended fax AT commands and the modem
responds with a set of status report result codes. During data state, compressed
fax image data is flowing between the modem and computer. The default serial
connection speed is 38400 bps, and it is higher than the fax link rate. CTS/RTS
hardware flow control is used to regulate the data flow.

The Omni 288S accepts the extended fax AT commands to set the modem mode
and fax parameters. Besides the extended fax AT commands, the modem accepts
all the other AT commands described in this chapter. For instance, you can use
ATD to make a fax call, or ATA to answer an incoming fax call. When using the
extended Fax AT commands, you need to send the command ATFCLASS=6 first.
Following are the fax related AT commands:

Mode Setting

Command Function

#F Set the modem into V17G3 FAX mode same function as the

extended AT command AT&N32.

#B0 Set fax receiving mode. The connection parameters and received

fax data are sent to DTE continuously following the connect
message. (Default)

#B1 Set fax receiving mode. The messages are separated from the

received fax data. The modem sends CONNECT FAX and
ZyXEL first, then it waits for the DC2 character (hex18) to send
the fax data. When the modem receives a DC2 from the DTE, it
starts to send the fax connection
parameters/SnnnnVnTnRnLnCnP<string><CR><LF> then the
received fax data. In this mode, the modem will wait for DC2 at
the beginning of every page. The DTE software should detect the
page separator RTC and then sends the DC2 to receive the next
page of fax data. This mode is used with a BBS receiving faxes.

#B2 This mode is for the polling feature of the modem. In this mode,

the modem will send a polling signal to the remote fax device to
ask to receive a fax from the remote fax device. The received
fax data will be sent to the DTE continuously following the
message.

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Chapter 9 - Fax Operation

Command Function

#B3 Displays the ring cadence.

Parameter Setting

Command Function

#V0 Set to normal vertical resolution.
#V1 Set to high vertical resolution.
#T0 Set to one dimensional coding scheme.
#T1 Set to two dimensional coding scheme.
#R0 Set recording width: 1728 picture elements along a scan line

length of 215 mm.

#R1 Set recording width: 2048 picture elements along a scan line

length of 255 mm.

#R2 Set recording width: 2432 picture elements along a scan line

length of 303 mm.
#L0 Set maximum recording length: A4 (297 mm ).
#L1 Set maximum recording length: B4 ( 364 mm ).
#L2 Set maximum recording length: unlimited.
#C0 Set minimum scan line time capability the receiver: 20 ms at

3.85 line/mm, T(7.7)=T(3.85).

#C1 Set minimum scan line time capability the receiver: 5 ms at 3.85

line/mm, T(7.7)=T(3.85).
#C2 Set minimum scan line time capability the receiver: 10 ms at

3.85 line/mm, T(7.7)=T(3.85).

#C3 Set minimum scan line time capability the receiver: 20 ms at

3.85 line/mm, T(7.7)=1/2 T(3.85).

#C4 Set minimum scan line time capability the receiver: 40 ms at

3.85 line/mm, T(7.7)=T(3.85).

#C5 Set minimum scan line time capability the receiver: 40 ms at

3.85 line/mm, T(7.7)=1/2 T(3.85).

#C6 Set minimum scan line time capability the receiver: 10 ms at

3.85 line/mm, T(7.7)=1/2 T(3.85).

#C7 Set minimum scan line time capability the receiver: 0 ms at 3.85

line/mm, T(7.7)=T(3.85).
#P<string> Set local phone number the phone number following the

character 'P' can up to 25 characters. The modem will exchange

this phone number with the remote fax machine during initial

handshaking.

9-14

Chapter 9 - Fax Operation

Status Report Result Codes

When the Omni 288S is set in the fax mode, each ATD or ATA command will
make the modem try to establish a fax connection. The Omni 288S will send a
status report result code back to the DTE (computer).

NO DIAL TONE Tried to dial but no dial tone is detected.
NO CARRIER Handshake fails or no carrier is detected or time-out.
BUSY Other party's phone line is busy.
NO ANSWER Quiet answer is not detected before time-out.
CONNECT FAX See below.

When a fax connection is successfully established, the modem returns this
message:

CONNECT FAX/SnnnnVnTnRnLnCnP<string>

This message includes the connection speed and the fax parameters explained in
the table below.

Field Description

Snnnn Fax connection speed; nnnn is a 4-digit number representing

the connection speed. nnnn =1440, 1200, 9600, 7200, etc.,

1440 and 1200 stand for 14400 and 12000.
V n Vertical resolution; n = 0 or 1.
Tn Coding scheme; n = 0 or 1.
Rn Recording width; n = 0, 1, or 2.
Ln Recording length; n = 0, 1, or 2.
Cn Scan line time; n = 0 to 7.
P<string> Remote fax number.

After each fax disconnection, the following result code is sent back to the DTE:

DISCONNECTnP<string>

This result code informs DTE of the disconnecting status.

Field Description

DISCONNECT0 Disconnect with remote confirmation.
DISCONNECT1 Disconnect without remote confirmation.
P<string> Remote fax number.

The basic AT commands ATV0 and ATQ1 do not affect the above CONNECT
and DISCONNECT status report result codes. The modem will always return the
same status format as above.

9-15

Chapter 9 - Fax Operation

Flow Control

In extended fax AT command mode, the Omni 288S always uses hardware
(CTS/RTS) flow control. The flow control signaling used sending a fax is:

 CTS is used by the Omni 288S to flow control the DTE. When the modem

turns CTS off, the buffer inside the modem is full and cannot accept any more
data. The computer should send data only when CTS is ON.

 RTS is used by the computer to signal the Omni 288S that the fax message is

finished. As soon as RTS off is detected, the modem starts the post message
handshaking to make sure that the remote facsimile has received the fax
message successfully. Then it hangs up the phone and sends a status report to
the DTE.

If you want to send a multi-page fax, just add the RTC signal between the fax
message of two pages. The modem detects the RTC signal automatically,
handshakes the multi-page procedure with the remote facsimile and sends the next
page message.

The following flow control signaling is used while receiving a fax:

 CTS is not used when receiving fax.
 RTS is used to inform the Omni 288S that the computer cannot accept data at

this moment. The modem will not pass received data to the DTE if RTS is
turned off.

When finished receiving the fax message, the Omni 288S will turn off CD then
send a status report result code to the DTE.

Fax Reception from a BBS

The Omni 288S can automatically detect data and fax calls and allow BBS
software to receive faxes on the same phone line. To allow your BBS to receive
incoming faxes, make the following set-up changes in your BBS:

1. Add the string #B1+FCLASS=6 to the init string. Be sure the +FCLASS=6
command is the last command.

2. Change one of the messages in the list to CONNECT FAX.

3. Set the external mail string to ZyXEL and give it an error level.

4. In your BBS batch file, if the error level matches the external mail, execute

rcvfax 2 /p:comport [/w:workpath]

This setting will enable the BBS to receive a fax and store it automatically.

The following is a sample setting for the FrontDoor system.

 Add these commands to the init string:

9-16

Chapter 9 - Fax Operation

X7#B1+FCLASS=6

 Change the connection message to:

300 CONNECT 4800 CONNECT 4800
1200 CONNECT 1200 9600 CONNECT 7200
1275 CONNECT FAX 19200 CONNECT 9600
2400 CONNECT 2400 38400 CONNECT 14400

 Set external mail as:

String Error Level

1 ZyXEL 100
2
3

The following is a sample setting in the BINKLEY.CFG file for a Binkley system.

Init AT&FX7S0=1#B1+FCLASS=6
ExtrnMail ZyXEL errorlevel

9-17

Chapter 10 - Voice Mode Operation

Chapter 10 - Voice Mode Operation

Voice mode refers to the Omni 288S’s ability to digitize incoming voice
messages, which the computer stores and forwards. It also means the modem can
playback the recorded digitized voice either off-line for local message listening
or on-line for a message announcement. For interactive voice applications, DTMF
tone detection capability is important so a computer can react according to the
remote caller's touch tone input. This Chapter summarizes the use of the Omni
288S’s numerous voice features.

Voice Data Compression

The main issue in digitized voice mode is the amount of storage required. A good
phone quality voice digitization will produce about 64 Kbits of data for each
second of voice recording. At this digitization rate, the hard disk will be filled up
quickly by digitized voice data. Speech compression is needed to reduce the rate
of digitized data. A relatively simple ADPCM (Adaptive Differential Pulse Code
Modulation) algorithm can reduce the speech data rate to half the rate and
maintain about the same voice quality. This algorithm can also be used to reduce
the speech data rate to 1/3 or 1/4 of the original rate, but with voice quality
degradation. Reducing the speech data rate further and maintaining good voice
quality requires a sophisticated and complicated signal processing algorithm. It
also requires a lot of digital signal processing computation power.

The Omni 288S supports seven voice digitization schemes:

Compression Method Bits/Sample Rates (samples/second)

ZyXEL 2 ADPCM 2 7200, 8000, 9600, 11025
ZyXEL 3 ADPCM 3 7200, 8000, 9600, 11025
ZyXEL 3 ADPCM (new) 3 7200, 8000, 9600, 11025
ZyXEL 4 ADPCM 4 7200, 8000, 9600, 11025
DVI ADPCM 4 7200, 8000, 9600, 11025
A-law PCM 8 7200, 8000, 9600, 11025
u-law PCM 8 7200, 8000, 9600, 11025

Note: The New 3-ADPCM scheme is a 3-bit ADPCM scheme with

added sync bits in the voice data. This helps to avoid loss of
data synchroni zation due to dat a errors or data l oss. I t i s the
recommended 3-bit ADPCM scheme. It will automatically
recover from data errors when playing without producing noisy
voice signals.

10-1

Chapter 10 - Voice Mode Operation

Automatic Detection of Voice, Data, Fax

Since there is no way to standardize the way a human voice should behave in
telephone calling and answering, it is nearly impossible to automatically
distinguish a voice call from a fax call from a data call. One common way of
accomplishing this task is to combine the use of a digitally recorded voice
message with DTMF tone detection. The voice message instructs the caller to
press one number on the touch-tone keypad if they want to send a fax, or another
number if they want to talk. By detecting which DTMF tone was sent, the modem
and software can switch to the appropriate mode and handle your call
accordingly. If no tone is received by the timeout, the Omni 288S will assume it is
a data call and begin its modem handshaking process.

The shortcoming of this process is that some modems will be confused by the
initial voice message portion, and will not be able to connect. Even if the data
call is successfully connected, the long delay before handshaking may not be
acceptable in some applications.

Some software packages use an initial period of silence when answering, and
detect if there is voice energy to decide if it is a voice call.

The Omni 288S can recognize a fax or data call more quickly if a calling tone is
received. In this case, the voice announcement can be omitted.

Voice Input/Output Devices

Microphone and Speaker Jacks

On the back of the Omni 288S, there are two jacks for external microphone and
speaker connections. These jacks are convenient means for voice input/output.
The speaker jack is capable of directly driving an 8 ohm speaker. When an
external speaker is plugged into the speaker jack, the internal speaker is
automatically shut off. The speaker jack only drives one speaker. If you have two
speakers with a stereo plug, use a plug adapter that will enable both speakers to
be driven by one source out of the speaker jack. If you are connecting the
speaker jack output to an amplifier, insert some attenuation in between. The
speaker jack output signal may be too strong for the amplifier.

Voice Input/Output Device Selection

To take advantage of the voice functions of the Omni 288S, you can use either the
speaker and microphone jacks or the handset of any telephone. The voice
input/output device selection is controlled by voice AT commands. Generally,
the user makes input/output selection through application software packages
according to the program’s instructions. The user need not worry about using AT
commands to make the selection. Below are some specific directions for cases
where manual selection through AT commands are necessary.

10-2

Chapter 10 - Voice Mode Operation

Choose your Input/Output Device by typing the appropriate AT commands.
To select the telephone (connected to phone jack) as your I/O device, type:

AT+VLS=1<Enter>

To select the external microphone as your input device, type:

AT+VLS=8<Enter>

To select the modem internal speaker as your output device, type:

AT+VLS=16<Enter>

Note: The external speaker simply replaces the internal speaker. As

an output device. Device selection remains the same.

Voice Mode Application Examples

Shown below are six examples of some common uses of the Omni 288S voice
mode operation, and the AT command sequences used to initiate them. The voice
application software you use will normally perform these functions automatically.

Recording a greeting message

Commands DCE Responses Description

AT+FCLASS=8 OK Switch to voi ce mode.
AT+VSM=? (reference table) List the compression schemes
AT+VSM=4 OK Select 4-bit ADPCM

compression method.

AT+VLS=1 VCON Activate the telephone set on the

PHONE jack.

AT+VRX CONNECT

<DATA>

<DLE><!> <DATA>

<DLE><ETX>
OK

AT+VLS=0 OK Deactivate the telephone on the

AT+FCLASS=0 OK Return to data mode.

Start recording.

Stop recording, and return to
command state.

PHONE Jack.

Playing a voice file through the internal speaker

Commands DCE Responses Description

AT+FCLASS=8 OK Switch to voice mode.
AT+VSM=? (reference table) List the compression schemes
AT+VSM=2 OK Select 2-bit ADPCM

compression method.
AT+VLS=16 VCON Activate internal speaker.
AT+VTX <DATA>

<DLE><ETX>
OK

10-3

Start replay, then return to the

command state.

Chapter 10 - Voice Mode Operation

Commands DCE Responses Description

AT+VLS=0 OK Deactivate internal speaker.
AT+FCLASS=0 OK Return to the data mode.

Plaing a voice file through the phone line

Commands DCE Responses Description

AT+FCLASS=8 OK Switches to voice mode.
AT+VSM=? (reference table) List the compression schemes
AT+VSM=4 OK Select 4-bit ADPCM

compression method.
AT+VLS=2 VCON Connect to line.
AT+VTX CONNECT

<DATA>
<DLE><ETX>

OK
AT+VLS=0 OK Deactivate line connection.
AT+FCLASS=0 OK Return to the data mode.

Start replay.

Return to command state.

Omni 288S as a Voice answering machine

Commands DCE Responses Description

AT+FCLASS=8 OK Switch to voice mode.
AT+VSM=? (reference table) List the compression schemes
AT+VSM=4 OK Select 4-bit ADPCM for

greeting message.
AT+VLS=2 VCON Connect to line.
AT+VTX CONNECT

<DATA>
<DLE><ETX>
OK

AT+VSM=2 OK Change to 2-bit ADPCM for

AT+VRX CONNECT

<DATA>
<DLE>b
<DLE>q

<DLE><!>

<DATA>
<DLE><ETX>

OK
AT+VLS=0 OK Deactivate line connection.
AT+FCLASS=0 OK Return to data mode.

or

Start to play greeting message.

Return to command state.

recording.
Start recording.

DCE detects busy tone
long period of quiet.
Stop recording.
DCE delivers remaining data.

Return to command state.

or

Omni 288S as a Fax answering machine

Command DCE Response Description

10-4

Chapter 10 - Voice Mode Operation

Command DCE Response Description

AT+FCLASS=8 OK Switch to voice mode.
AT+VSM=? (reference table) List the compression schemes
AT+VSM=4 OK Select 4-bit ADPCM for

greeting message.
AT+VLS=2 VCON Connect to line.
AT+VTX CONNECT

<DATA>
<DLE>c
<DLE>’
<DATA>
<DLE><ETX>

OK
AT+FCLASS=2 OK Switch to fax mode.
ATA Try to handshake fax

mode.

or

n’

Start to play greeting message.

T.30 fax calling tone
DTMF digit 'n' detected.

Return to command state.

Answer fax call.

or

Omni 288S as a Data answering machine

Command DCE Response Description

AT+FCLASS=8 OK Switch to voice mode.
AT+VSM=? (reference table) List the compression schemes
AT+VSM=4 OK Select 4-bit ADPCM for

greeting message.
AT+VLS=2 VCON Connect to line.
AT+VTX CONNECT

<DATA>
<DLE><ETX>
OK

AT+VSM=2 OK Change to 2-bit ADPCM for

AT+VRX CONNECT

<DATA>
<DLE>

s

<DLE><!>

<DATA>
<DLE><ETX>

OK
AT+FCLASS=0 OK Switch to data mode
ATA Try handshake data

mode.

Note:

If a modem data tone is detected (indicated by a <DLE>e
response) , the modem should be switched to data mode.

Start to play greeting message.

Return to command state.

recording.
Start recording.

DCE detects silence.
Stop recording.
DCE delivers remaining data.

Return to command state.

Answer data call.

10-5

Chapter 10 - Voice Mode Operation

Voice States and Operation Modes

The Omni 288’s Voice Mode DCE control interface adheres to the TIA TR29.2
committee IS-101 Interim Standard. ZyXEL is continuously enhancing its
modems' voice capability and voice feature implementation. Please refer to
future manual amendments or firmware release notes for updated details.

In ZyXEL Voice Mode, three states exist that correspond to the flow direction of
voice data between the modem (DCE) and the computer (DTE). These are
outlined in the table below.

Voice State Data Flow Direction

Voice Command State No data transfer other than event reports
Voice Data Reception State Voice data transfer from DTE to the DCE
Voice Data Transmission State Voice data transfer from DCE to the DTE

Note: Voice data DTE/DCE transfer is half-duplex.

The DCE may issue event detection reports at any time, regardless of the DCE
state. These reports may be tone or cadence events such as calling tone. ZyXEL
provides the Service Level C Event Detection Capabilities of IS-101 as follows:

Event Description DCE Voice State

RING Command
Ringback Command
Fax or Data Answer (e.g., 2100 Hz) Command
BUSY Receive, and Command
DIALTONE Receive, and Command
DTMF Received Receive, Transmit, and Command
Fax Calling Tone Receive, Transmit, and Command
Presumed Hang-up (SILENCE) Time-out Receive
Presumed End of Message (QUIET) Time-out Receive
Mandatory Receive Buffer Overrun Receive
Mandatory Transmission Buffer Underrun Transmit

Voice Command State

The DCE is in the Voice Command State and is ready to accept commands when
the DCE is operating in voice mode. Additionally, the DCE must not be
communicating with a remote station, or with any local devices capable of
translating analog signals to voice (e.g., speaker), or voice signals to analog (e.g.,
microphone).

The DCE considers data transfers from DTE commands and returns responses
back to the DTE after processing these commands. While doing so, the DCE also
monitors the line which connects the DCE to remote stations or to local devices to
detect events. The DCE later reports to the DTE, signals carried over the line,
such as tones, as well as PSTN generated control and notification signals, such as
ringing.

10-6

Chapter 10 - Voice Mode Operation

The Voice Command State provides several DTE options. The modem may wait
for an unspecified time after playing a welcome message, or switch to other
modes as part of a DTE call discrimination algorithm.

Voice Data States

The DCE is in Voice Data State when the DCE is operating in voice mode and is
communicating with a remote station or with one or more local devices which are
capable of translating analog signals to voice (e.g., speaker) or voice to analog
(e.g., microphone). The DTE transfers data to the DCE for transmission to the
remote station. The DCE transfers data to the DTE after reception from the
remote station. The DCE monitors data and the control signals to detect events
which the DCE later reports to the DTE pertaining to the line connecting the DCE
to the remote station, and pertaining to requests from the DTE.

Voice Data State has two sub-states. These are Voice Transmission State and
Voice Reception State.

Voice Data Transmission State

The DCE is in Voice Transmission State when the DCE receives digitized data
from the DTE, converts the binary data into an analog signal, and transmits the
analog signal to the remote station or to one or more local device destinations
such as a speaker. While transmitting the data, the DCE:

1. monitors the line which connects the DCE to the remote station or to one or
more local devices to detect events which the DCE reports to the DTE and

2. does not expect to receive, digitize, or process any incoming analog signals
for transfer to the DTE. Events detected when monitoring are notification
signals such as busy.

The Voice Data Transmission State is terminated by either of the following two
methods:

1. The DCE receives a <DLE><ETX> shielded code from the DTE.

2. When a DTE/DCE inactivity time-out occurs.

After termination of the Voice Data Transmission State, the DCE will enter the
Voice Command State.

Voice Data Reception State

The DCE is in the Voice Reception State when the DCE digitizes the analog
signal from the remote station or from local device sources such as a microphone.
The analog signal is converted into binary data, which is compressed or
otherwise processed. The resulting data is transferred to the DTE. While
receiving the data, the DCE:

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Chapter 10 - Voice Mode Operation

1. monitors the line we which connects the DCE to the remote station or to one
or more local devices t detect events which the DCE reports to the DTE.
These events pertain to signals carried over the line such as tones, and to
PSTN -generated control and notification signals such as ringing.

2. does not expect to receive digitized data from the DTE, perform conversion,
or transmit the analog signal to the remote station or to one or more local
devices.

The Voice Reception State is terminated by either of the following two methods:

1. The DCE receives <DLE><!> shielded code from the DTE.

2. The DCE receives characters other than <XON>, <XOFF> or a shielded
code from the DTE.

After termination of the Voice Data Reception State, the DCE enters the Voice
Command State.

Events and Actions with Shielded Code

Event Detection and Reporting

The voice mode may return many more event detection reports than the familiar
RING result code used in data/fax modems. While in voice mode, the DCE can
detect DTMF tones. The DCE will report the event to the DTE at the time of
detection by inserting a <DLE> shielded code into the data to the DTE. The form
of the report is <DLE><code>, where <code> can be one of the possible
character values listed in the following table.

<code> Event Report Description

<DLE> (0x10) Two contiguous <DLE><DLE> codes indicate a single <DLE> in

the data stream.
<SUB> (0x1A) <DLE><DLE> in the data stream.
<DC2> (0x12) Concatenate reception data streams. The DCE sends this code to

indicate the start of a new voice data stream with the same

parameters as the last stream for the purpose of a timing mark.

The DCE resets its compressors before transmitting the data after

the <DLE><DC2> codes. This resync generation timer is defined

by the command AT+VSY.
<ETX> (0x3) End Data State. The DCE sends this code to indicate the end of

the voice data.
R (0x52) Ring: The <DLE> shielded version of the RING result code
1 (0x31) DTMF 1
2 (0x32) DTMF 2
3 (0x33) DTMF 3
4 (0x34) DTMF 4
5 (0x35) DTMF 5
6 (0x36) DTMF 6

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Chapter 10 - Voice Mode Operation

<code> Event Report Description

7 (0x37) DTMF 7
8 (0x38) DTMF 8
9 (0x39) DTMF 9
0 (0x30) DTMF 0
A (0x41) Extended Keypad DTMF A
B (0x42) Extended Keypad DTMF B
C (0x43) Extended Keypad DTMF C
D (0x44) Extended Keypad DTMF D
* (0x2A) Extended Keypad DTMF *
# (0x23) Extended Keypad DTMF #
o (0x6F) Buffer Overrun.
c (0x63) T.30 fax calling tone (1100Hz). The time interval between

reports is 4.0 seconds.
e (0x65) Data modem calling tone (1300Hz). The time interval between

report is 4.0 seconds.
h (0x68) Line current break (local phone goes on-hook).
H (0x48) Line current detected (local phone goes off-hook).
s (0x73) Silence detected. The DCE has determined that there was no

voice energy present at the beginning of the voice receiving

session followed by a period of silence greater than the amount of

time selected by the +VSD command.
q (0x71) Quiet detected. The DCE has determined that there was voice

energy present at the beginning of the voice receiving session

followed by a period of silence greater than the amount of time

selected by the +VSD command.
$ (0x24) Bong Tone (300Hz for 1 second).
l (0x6C) Loop current interruption. This may be a remote hang-up.
b (0x62) BUSY. If the DCE continues to detect BUSY , it may report

this event repeatedly. The delay between reports is 4.0 seconds.
u (0x75) Transmission Buffer Underrun. The DCE will report this code if

the DCE's buffer becomes empty without first receiving a

<DLE><ETX> or a <DLE><CAN> command.
a (0x61) Data answer tone. The delay between reports is 4.0 seconds.

Action Commands in Voice Data State

The DTE may initiate actions by inserting a <DLE> shielded code into the data to
the DCE. The form of the action is <DLE><code>, where <code> is one of the
character values listed in the following table:

<code> Event Report Description

<NUL> (0x0) Does nothing. The DTE can use the code to refresh the

DTE/DCE Inactivity Timer, instead of XON.
<DLE> (0x10) Two contiguous <DLE><DLE> codes indicate a single <DLE> is

in the data stream.
<SUB> (0x1A) <DLE><DLE> in the data stream.

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Chapter 10 - Voice Mode Operation

<code> Event Report Description

u (0x75) Turn up the volume or gain by one unit.
d (0x64) Turn down the volume or gain by one unit.
p (0x70) Pause Data State: The DCE suspends sending analog data to the

currently selected analog destination. While pausing, the DCE will

maintain the contents of its internal buffer and the state of its

compressors, continue in the Data State, and send silence to the

analog destination.
r (0x72) Resumes Data Transmission State: The DCE resumes sending

the contents of the DCE buffer to the currently selected analog

destination. Before resuming sending the analog signal to the

analog destination, the DCE will not reset the contents of its

internal transmission buffer, nor reset the compressors.
<ETX> (0x3) Ends Data Transmission State: The DTE sends this code to

signify the end of the voice data from the DTE and cause the

DCE to return to the Voice Command State. The DCE will

complete the transmission of the contents of its buffer before

switching to the Voice Command State and returning the OK

result code
<DC4> (0x14) Clears the transmission buffer of voice data and ends Data

Transmission State: The DTE sends this code to indicate the end

of the voice data from the DTE and cause the DCE to return to

the Voice Command State. The DCE will clear its internal

transmission buffer before switching to the Voice Command State

and returning the OK result code.
<CAN> (0x18) Clears the transmission buffer of voice data: This code

commands the DCE to (1) clear its internal transmission buffer;

(2) get ready for a new voice data stream with the same

parameters as the last stream; and (3) reset its compressors and

send silence over to the analog destination while paused.
<FS> (0x1C) or
<DC2> (0x12)

! (0x21) Ends Data Reception State. The DTE sends this code to indicate

Concatenate data streams: The DTE sends this code to indicate

the start of a new voice data stream with the same parameters as

the last stream without first returning to the Voice Command

State. The DCE will transmit the remainder of its internal

transmission buffer and reset its compressors before transmitting

the data following the <DLE><FS> or <DLE><DC2> codes.

the end of voice data reception and the return to Voice Command

State. The DCE will discard the contents of its buffer before

switching to the Voice Command State and returning the OK

result code.

Voice AT Commands

The following is a summary of voice AT commands supported by the Omni 288:

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Chapter 10 - Voice Mode Operation

AT Command Syntax

AT is the command line prefix. Voice commands take one of the following forms:

Command-Form Syntax Command-Form Function

+V<CM>? Read current setting.
+V<CM>=? Read permissible settings.
+V<CM>=<string> Set single-value parameter.
+V<CM>=<value_string> Set compound parameter.

Voice AT commands begin with ‘AT’ followed by a ‘+V’ command prefix.
<CM> represents the command character/s. The command parameters can are
made up of <value> and/or <value_string> parameter types. The <value_string>
type consists of multiple values separated by commas or semicolons.

The first two command-forms are for read actions, the last two are for write
actions. A command line may contain either or both action types or be of the read
or write type only.

Response Syntax

For each command line received, the modem issues a response to each command
in the command line followed by a final response.

Each command response is of the form:

<CR><LF>
<value>(or) <value range> (for ? or =? read commands)
<CR><LF>

with a final response of:

<CR><LF>
OK (or) ERROR
<CR><LF>

The final response is OK if all the commands in the command line have been
successfully executed, otherwise it is ERROR.

Note: <CR><LF> characters will not be shown in further examples.

Flow Control

Flow Control is necessary to match the DTE-DCE data rate to the line signaling
rate and to the analog conversion of the voice signals and data. For the Omni
288S, both software XON/XOFF and hardware RTS/CTS flow control are used ­the software flow control is the default setting. The DTE turns off the flow
control, but some other method may be used to avoid overrun of the buffer.

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Chapter 10 - Voice Mode Operation

The DTE can select the flow control method in voice mode by using the +FLO
command (defined in Class 2 and 2.0).

Supported Commands in Voice Mode Operation

 ATD (with +FCLASS=8)

This command causes the DCE to dial a phone number. The DCE uses the current
destination setting to perform a dial action. If +VLS is equal to zero at the time of
the ATD command, the DCE will return an ERROR result code.

The DCE attempts to determine when the remote station has gone off-hook by
ringback detection and disappearance (see the +VRA and +VRN commands,
respectively). Once the DCE has determined with high confidence that the remote
station has gone off hook, the DCE returns the OK result code. For example, the
DCE reports this result code when the DCE has determined on answer that the
remote station is a data modem. The DCE may also issue this result code when the
DCE has assumed that the remote station has gone off-hook by actions associated
with the +VRA and the +VRN commands.

The DCE issues the NO ANSWER result code when the DCE has continuously
detected ringback for the amount of time specified in S-register S7.

 ATH (with + FCLASS=8)

This command causes the DCE to hang up the phone. In voice mode, this
command is equivalent to the +VLS=0 command, and the DCE to the data mode
(+FCLASS=0) with auto-baud, regardless of the state of the +VNH command.
When the +VNH=0 command is in effect and the DCE is not in voice mode, the
ATH command behaves as for the data mode.

This command does not change any of the voice mode parameters such as +VSM,
+VSD, etc. When the +VNH=1 or +VNH=2 command is in effect and the DCE is
not in voice mode, the DCE issues an OK result code as a result of the ATH
command, but the DCE may or may not go on-hook depending on the setting of the
+VNH command. As part of the call discrimination algorithm, the DCE may
switch to other modes, such as facsimile or data, in order to try handshakes in
these modes. Voice mode does not support the ATH1 command.

 AT+FCLASS=<mode>

This command selects a DCE mode. Either data, fax, or voice. The DCE
recognizes the value of 8 as the Voice Mode.

<mode> DCE mode

0 Data Mode
1 Fax Mode, Service Class 1 (TIA/EIA-578)
2 Fax Mode, Service Class 2 (TIA PN-2388)

2.0 Fax Mode, Service Class 2.0 (TIA/EIA-592)
6 Fax Mode, ZyXEL Fax AT Commands

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Chapter 10 - Voice Mode Operation

8 Voice Mode (TIA IS-101)

The DCE returns the OK result code if the DCE accepts the command. The DCE
returns the ERROR result code if the <mode> subparameter is not permitted.

 AT+FCLASS?

The DCE returns the current mode setting followed by the OK result code.

 AT+FCLASS=?

The DCE returns permitted modes. The response is (with S57.4=1):

0,1,2,2.0,6,8,Z
OK

 AT+VLH=?

This enables the DTE to inquire the hook status of the connected local phone. The
DCE will return 0 for on-hook and 1 for off-hook status.

 AT+VNH=<hook>

The DCE enables or disables automatic hang-up to a varying degree for data and
fax modes.

<hook> Hook Control Description

0 The DCE retains automatic hang-ups as is normal in the other mode

such as hanging up the phone when the DCE does not detect a data
carrier within a given time interval). (Default)

1 The DCE disables automatic hang-ups usually found in the other

Non-Voice Mode.

2 The DCE disables automatic hang-ups in the other Non-Voice

Mode. The DCE only performs a "logical" hang-up (returns the OK
result code).

 AT+VNH?

The DCE returns the current hang-up setting, followed by the OK result code.

 AT+VNH=?

The DCE returns permitted hang-up modes. The response is :

0,1,2
OK

 AT+FLO=<method>

The DCE selects the type of flow control provided and used.
<method> Flow Control Method

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Chapter 10 - Voice Mode Operation

<method> Flow Control Method

0 XON/XOFF and RTS/CTS flow control turned off
1 Use software XON/XOFF flow control in either direction.
2 Use hardware RTS/CTS flow control.

The DCE returns the OK result code if the DCE accepts the command. The DCE
returns the ERROR result code if the <method> subparameter is out of range.

 AT+FLO?

The DCE returns the current flow control setting, followed by the OK result code.

 AT+FLO=?

The DCE returns permitted flow control methods. The response is:

0,1,2
OK

Voice Mode Action Commands

 AT+VIP

The DCE will initialize all voice parameters to the default settings as follows:

Parameter Related Commands Default Value

Silence threshold +VSD 15
Hang-up code +VNH 0
Compression method +VSM 2 (2-bit ADPCM)
Beep tone interval +VTD 50 (unit: 10 ms)
Inactivity timer +VIT 70 (unit: 0.1 s)
Silence interval +VSD 70 (unit: 0.1 s)
Ringback timer +VRA 70 (unit: 0.1 s)
Ringback timer +VRN 10 (unit: 1 s)
Reception Gain +VGR 0
Transmission Gain +VGT 128
Resync timer +VSY 0 (disabled)
DTMF detection
intervaland threshold
Flow control method +FLO 1 (software)

The DCE returns the OK result code if DCE accepts this command or returns the
ERROR result code if the DCE is not connected

+VDD 8 (unit: 5 ms) 5

 AT+VRX

The DCE starts the voice reception process by first returning the CONNECT
result code to the DTE. After this is reported, the DCE sends <DLE> shielded
voice data to the DTE. There are three ways to leave the Voice State:

1. The DTE sends a character other than <XON>, <XOFF> or a shielded code.

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Chapter 10 - Voice Mode Operation

2. The DTE sends a <DLE><!> shielded code.

3. A DTE/DCE Inactivity Timer time-out.
Upon termination of the voice state, the DCE will append a <DLE><ETX>

character pair, followed by the OK result code. The DCE then returns to Voice
Command State.

The Inactivity Timer is in effect while the reception operation is in progress. If
the DTE wishes to use this timer and stop the DCE from performing unwanted
restarts, the DTE must assure that there is data sent from the DTE to the DCE
often enough to refresh the timer; the DTE may use the <DLE><NUL> shielded
code as a no-operation command to refresh the timer.

 AT+VTS=<string>

This command causes the DCE to issue DTMF single frequency tones, and
optionally, double frequency tones. The DCE accepts <DLE><!> to abort playing
tones, the OK result code, and to the Voice Command State.

The tone generation string consists of elements in a list with each element
separated by a comma. Each element can be:

1. A single ASCII character in the set 0-9, A-D, #, and *. The DCE interprets
the single ASCII character as a DTMF digit with a duration given by the
+VTD command.

2. A string enclosed in square brackets, "[ ].” The DCE interprets the values in
square brackets as a general dual tone and duration selection. The quantity
within the square brackets consists of a three element list. The first element is
the first frequency, the second element is the second frequency, and the third
element is the tone duration in 10 ms intervals.

3. A string enclosed in curly braces, "{}.” The DCE interprets the quantity in
the braces as a DTMF tone with a different duration than that given by the
+VTD command. The quantity in the curly braces consists of a two element
list. The first element is the DTMF tone character and the second element is
the tone duration in 10 ms intervals. For every inter-element comma in the
list, the DCE pauses for an interval set by the +VTD command.

 AT+VTS=?

This command causes the DCE to report the allowable tone frequency range and
duration range. The Omni uses two tones, both in the frequency range of 20 to
4800 Hz, and a duration range from 0 to 10 seconds. The response is as follows:

(20-4800),(20-4800),(0-1000), 0-9, A-D, *, #
OK

 AT+VTX

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Chapter 10 - Voice Mode Operation

This command causes the DCE to start the voice transmission process. The DCE
begins the Voice Transmission Mode by returning the CONNECT result code to
the DTE. After this report, the DCE accepts <DLE> shielded voice data from the
DTE. The DTE shall send the data in the format previously selected by the +VSM
command and use the flow control method selected by the +FLO command.

There are two ways to leave the Voice Transmission State:

1. The DTE sends a <DLE><ETX> shielded code.

2. A DTE/DCE Inactivity Timer time-out.

Item (1) is the DTE initiated means of terminating the Voice Transmission State,
and item (2) is a DCE-initiated means of terminating the Voice Transmission
State. Upon termination of the Voice Transmission State, the DCE sends the OK
result code and returns to Voice Command State.

Voice Mode Configuration Commands

 AT+VGR=<gain>

This command causes the DCE to set the gain for the received voice samples. The
gain is an unsigned octet value. The normal value is 128. A value larger than 128
indicates a larger gain than normal, and a value smaller than 128 indicates a gain
smaller than normal. A gain value of 56 corresponds to -18 dB gain, 128 for 0 dB,
and 200 for 18 dB, in 0.25 dB steps. A value of zero invokes Automatic Gain
Control on the DCE. The gain range is 56 to 200 and the default value is 0.

The DCE returns the result code OK if DCE accepts this command, or it returns
the result code ERROR if the <gain> parameter is out of range.

 AT+VGR?

The DCE will return current gain, followed by the OK result code.

 AT+VGR=?

The DCE will return all permitted values for the gain. The response is:

56-200
OK

 AT+VGT=<level>

This command causes the DCE to set the volume level, either by amplifying or
attenuating the signal, for the transmitted voice samples. The transmission gain (or
attenuation) is an unsigned octet value. The default value is 128. A value larger
than 128 indicates a larger gain than normal, and a value smaller than 128
indicates a gain smaller than normal. The level range is 56 to 200. A gain value of
56 corresponds to -18 dB gain, 128 for 0 dB, and 200 for 18 dB, in 0.25 dB steps.

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Chapter 10 - Voice Mode Operation

The DCE returns the result code OK if DCE accepts this command, or it returns
the result code ERROR if the <level> parameter is out of range.

 AT+VGT?

The DCE returns the current gain, followed by the OK result code.

 AT+VGT=?

The DCE returns permitted values for the gain. The response is:

56-200
OK

 AT+VIT=<timer>

This command sets the inactive time-out value for the DTE/DCE Inactivity Timer.
The default value is 7 seconds. Acceptable values are 0 to 255 with a unit of 0.1
second. The DTE can disable the Inactivity Timer by setting the value to zero.

The DCE returns the OK result code if DCE accepts this command, or it returns
the ERROR result code if <timer> is out of range.

 AT+VIT?

The DCE returns the current Inactivity Timer timeout value, followed by the OK
result code.

 AT+VIT=?

The DCE returns the permitted Inactivity Timer timeout values. The units are in

0.1 seconds. The response is :

0-255
OK

 AT+VLS=<device>

This command causes the DCE to select a voice I/O device. The permitted
<device> is as follows:

<device> Description

0 No voice I/O devices connected. Local phone connects to telco line.

The DCE is on-hook.

1 Voice I/O through local phone connected to POTS Port. Local Phone

provided with power to detect hook condition. The DCE is on-hook.
2 Voice I/O through Telco Line. The DCE is off-hook.
8 Voice Input through External Microphone. Local phone connects to

Telco Line. The DCE is on-hook.
16 Voice output to Internal Speaker. Local Phone connects to Telco Line.

The DCE is on-hook.

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Chapter 10 - Voice Mode Operation

The DCE returns the VCON result code (returns OK if S48.5=1) if the DCE
accepts this command, or it returns the ERROR result code if the <device> value
is not permitted.

 AT+VLS?

The DCE will return the current I/O device followed by the OK result code.

 AT+VLS=?

The DCE will return permitted I/O devices. The response is:

0,1,2,8,16
OK

 AT+VSD=<sds>,<sdi>

This command causes the DCE to set the silence detection sensitivity and the
required period of silence before the DCE can report silence detected at the end
of a voice reception either with the "Presumed End of Message" (QUIET) or
"Presumed Hang-up" (SILENCE) event reports.

<sds>: DCE silence detection threshold level a larger value of this
subparameter implies that the DTE wants the DCE to treat noisier condition
as silence. The actual value of this subparameter has no physical meaning.
The range of the sensitivity <sds> is from 0 to 31. A value of zero disables
the silence detection. The default value is 15.

<sdi>: The required period of silence before the DCE can report silence
detected either with the "Presumed End of Message" (QUIET) or "Presumed
Hang-up" (SILENCE) event report. A value of zero disables the DCE silence
detection. The range of the interval <sdi> is from 0 to 255 in units of 0.1
seconds. The default value is 70 (7 seconds).

The DCE returns the OK result code if DCE accepts this command, or it returns
the ERROR result code if <sds> or <sdi> is out of range.

 AT+VSD?

This command causes the DCE to report current <sds> and <sdi> settings. The
form of the response is:

<sds>,<sdi>
OK

 AT+VSD=?

This command causes the DCE to report the permitted range of <sds> and <sdi>.
The response is:

(0-31),(0-255)

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Chapter 10 - Voice Mode Operation

OK

 AT+VSM=<cml>,<vsr>

This command causes the DCE to select a compression scheme and sample rate as
follows:

<cml> Compression Scheme Bits/Sample <vsr> possible values

2 ZyXEL 2 ADPCM 2 7200, 8000, 9600, 11025
3 ZyXEL 3 ADPCM 3 7200, 8000, 9600, 11025
30 ZyXEL 3 ADPCM (new) 3 7200, 8000, 9600, 11025
4 ZyXEL 4 ADPCM 4 7200, 8000, 9600, 11025
40 DVI ADPCM 4 7200, 8000, 9600, 11025
80 A-law PCM 8 7200, 8000, 9600, 11025
81 u-law PCM 8 7200, 8000, 9600, 11025

The DCE returns the OK result code if DCE accepts this command, or it returns
the ERROR result code if any of the values are out of range.

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Chapter 11 - AT Command Set Summaries

Chapter 11 - AT Command Set Summaries

Basic AT Command Set

Command Options Function & Description Ref.

A/ Re-execute the last command once
A> Re-execute the last command once or repeat the last call

up to 9 times. (See also S8)

<any key> Terminate current connection attempt when enter in

handshaking state.

+++ Escape sequence code, entered in data state, wait for

modem to return to command state.

All the Following Commands Require a “AT” Prefix

A Go on-line in answer mode. (See also S39.2, S43.6)
Bn Handshake option S28.7

B0 * Select CCITT V.22 for 1200 bps
B1 Select Bell 212A for 1200 bps communication

D

s

0-9, #, * Digits for dialing
P Pulse dialing S23.1
T Ton dialing S23.1
, Pause for a time specified in S6. Remaining digits will be

; Return to command state after dialing
! Hook flash
@ Wait for a 5 second silence before proceeding
R Reverse handshake (go on-line in Answer mode) S17.5
W Wait for second dial tone. Remaining digits will be dialed

DL Repeat last ATD command
DS

E

H

I

L

M

n

n

n

n

n

n

n=0-49 Dial number stored in non-volatile RAM at location 'n';

E0 Echo off
E1 * Echo on

H0 * Hang up (on-hook) the modem or ISDN, same as 'ATH'

I0 Display numerical product code, same as 'ATI'
I1 Display product information and ROM checksum
I2 Display modem link status report
n=0-7
4 *

M0 Speaker always OFF
M1 * Speaker ON until call is answered

Dial s (numbers and options) that follow (see also S38.0,
S35.4). The options of s are listed as follows:

dialed as in-band DTMF.

as in-band DTMF

S44.3
use “+” to dial two consecutive numbers for bundling or
MPPP calls
Command mode local echo of keyboard commands S23.0

On/off hook control

Display inquired information

Speaker volume control. The higher the value, the higher
the volume
Speaker control S21.1-2

S24.5-7

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Chapter 11 - AT Command Set Summaries

Command Options Function & Description Ref.

M2 Speaker always ON
M3 Speaker ON after the last digit is dialed out and OFF

when carrier is detected

N

n

O Return to on-line state
O1 Force modem to request a retrain
Q

n

Sr.b=

n

Sr.b? Display value of bit 'b' of S-register 'r'
Sr=

n

Sr? Display value stored in S-register 'r'
T Ton dial S23.1
UPX Download firmware to the Flash EPROM usin Xmodem

V

n

X

n

Z

n

$ Basic command summary help

n=0-7
5 *

Q0 * Modem returns result code
Q1 Modem does not return result code
Q2 Modem returns result code but quiet after answering on a

V0 Display result code in numeric form. (See also S35.7 and

V1 * Display result code in verbose form.
n=0-7
5 *
n=0-4 Reset modem and set power-on profile. S15.5-7
Zn Reset modem and load user profile n (0-3).
Z4 Reset modem and load factory settings.

Ring volume control.'N0' will disable the audio ring
function

Result code displayed S23.7

RING (see also S42.2)
Set bit 'b' of S-register 'r' to value 'n'. 'n' is a binary digit
'0' or '1'

Set S-register 'r' to value 'n'. 'n' must be a decimal
number between 0 and 255

protocol
Sets display type for Result Codes S23.6

the result code table of 'ATXn')

Result code options, see the Options Table S23.3-5

S24.1-3

S40.1

11-2