ZyXEL Communications Comet 3356 User manual

Comet 3356
User’s Manual
Version 1.0
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ii
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.
Acknowledgments
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.
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.

iii
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 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.
This equipment may not be used on coin service provided by the telephone company.
Connection to party lines is subject to state tariffs.
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) RJ-11C modular jack.
Contacting ZyXEL
If you have questions about your ZyXEL product or desire assistance, contact ZyXEL
Communications Corporation in one of the following ways:
• Phone: In North America call between 8:00 AM and 5:00 PM PST at
[phone].

iv
Outside North America, you can dial [phone] EXT 252 between 8:00AM
and 5:00PM Taiwan time (GMT +8:00).
• Fax: ZyXEL in North America: [phone] or Taiwan: [phone].
• E-mail:
• Sales inquiries: [email protected] in North America.
[email protected] outside North America.
• Technical support: [email protected] in North America.
[email protected] outside North America.
• Product information: Visit our site on the World Wide Web:
http://www.zyxel.com.
• FTP: Information , such as ZyXEL software and ROM updates for North America
can be found at this FTP address: ftp.zyxel.com
For European versions and related files, use the address: ftp.zyxel.co.at
• Postal Service: You can send written communications at the following address:
ZyXEL Communications Corporation
6, Innovation Road II, Science-Based Industrial Park
Hsinchu, Taiwan 300, ROC
or
ZyXEL Communications Inc.
4920 E. La Palma Avenue
Anaheim, CA92807, USA

v
Table of Contents
Limited Warranty ii
FCC Part 15 Information ii
FCC Requirements iii
Contacting ZyXEL iii
1 Introduction 1
Unpacking Your Modem 1
Becoming a Registered Owner 1
2 Installation 3
Optional Steps for Comet Installation 3
Telephone Jack 4
Microphone 4
Speaker 4
Driver and Software Installation 4
Windows 95 Driver Installation 4
Windows 95 Dial-up Networking 6
Setup for DOS Fax/Modem Software 10
3 Basic Modem Operation 12
Understanding AT Commands 12
Using the Windows 95 Hyper Terminal Program 12
Dialing and Answering Techniques 13
Dialing using the ATD Command 13
Auto-Answer and Hook Controls 14
Making Your First Connection 14
Quick Tips when issuing AT Commands 14
Modem Result Codes 15
Viewing S Register Values 16
Changing S Register Values 16
Non-Volatile Memory 16

vi
Storing Phone Numbers 16
Dialing Stored Phone Numbers 16
Saving Settings and User Profiles 17
Default Modem Settings for PC’s 17
4 Advanced Data Communications 19
Front Panel LEDs 19
DTE Interface 19
UART 19
Serial Port 19
Serial RS-232C Cable 20
Communication Protocols and Speeds 20
Universal Protocol Compatibility 20
Error Control 21
CRC (Cyclical Redundancy Check) Error Detection 21
Data Compression 22
Run Length Encoding 22
Adaptive Frequency Encoding 22
String Coding 22
Hardware or Software Flow Control 23
Hardware CTS/RTS 23
Software XON/XOFF 23
5 Special Functions 24
Caller Number Delivery (Caller ID) 24
Caller ID Result Codes 24
Caller ID Inquiries 24
Caller ID Formatted Form Reporting 25
Distinctive Ring 25
6 AT Command Set Summaries 28
7 +MS Modulation Commands 34

vii
8 Status Registers & Result Codes 40
S-Registers "ATSn=x" 40
S-Register Definitions 40
Result Code Options 45
"ATXn" Result Code Option Table 45
9 Fax Operation 48
Modem as Fax Machine 48
ITU-T T.30 Fax Protocol 48
Fax Command sets 48
Defining the Fax Command Sets 49
Flow Control 49
FAX Class 1 AT Command Set 49
FAX Class 2 AT Command Set 50
10 Voice Operation 54
Voice AT Command Set 66

Introduction 1
1 Introduction
Congratulations on the purchase of your Comet 3356 modem - one of ZyXEL's premier
high-performance products. The Comet is world renown for its ability to maintain ultra
high speeds and clear, quality connections while communicating around the globe.
Unpacking Your Modem
Before you proceed, check all items you received with your modem against this list to
make sure nothing is missing. The complete package should include:
• One (1) Comet 3356 modem
• One (1) AC power adapter (external model)
• One (1) RJ-11 modular telephone cable
• One (1) Comet 3356 User’s Manual
• One (1) ZyXEL modem driver diskette with Windows 95 INF file and Comet 3356
User’s Manual
• One (1) Data/Fax software for Windows environments
• One (1) warranty/registration card
• One (1) ZyCD
• One (1) standard RS-232 cable
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 packaging materials for future storage or shipping needs.
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.

2 Introduction

Installation 3
2 Installation
This chapter covers the steps required to install your modem and install and configure
the Windows 95 driver.
1. Turn off your computer.
2. Open the rear panel on the back of your modem.
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.
4. Connect the serial cable. Plug one end of the serial cable into the SERIAL PORT
connector on the back of the modem. Plug the other end of the serial cable to the
back of your computer. Your Comet comes with a high-speed serial interface
capable of reaching DTE speeds of 115.2Kbps. Be sure that your PC serial port has
a high-speed 16550 compatible Universal Asynchronous Receiver Transmitter
(UART).
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 Comet on by raising the blue power switch. The PWR LED should come
on and the modem performs a self-test procedure.
7. Turn the computer back on.
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Optional Steps for Comet Installation
The Comet 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.

4 Installation
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.
Speaker
To connect an external speaker, connect it to the modem’s SPK jack found on the back
of the modem. 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 Comet.
Windows 95 Driver Installation
1. From the Windows 95 desk top click the Start button, then choose Settings, then
click Control Panel.
2. Double click on the Modem icon.
3. From the Modem Properties dialogue box click the Add button.
4. Select Don’t connect my modem; I will select it from a list. Then click Next.

Installation 5
5. Click the Have Disk button.
6. 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,
click the Browse button to find the location of the updated .INF file, then click
Open, Then click OK.
7. Select ZyXEL Comet 3356 from the list. Then click Next.

6 Installation
8. Select the COM port your modem is connected to and click Next. A final dialog
box will appear. Click Finish. You should see a window similar to the one below:
9. Click Close.
This completes the installation of your Comet 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.

Installation 7
1. From the Windows 95 desk top click the Start button, then click Programs,
Accessories, and Dial-up Networking.
2. From the Welcome to Dial-Up Networking dialogue box click Next.
3. Choose a name for your connection and select your modem type from the drop
down window. Then click on the Next button.
4. Enter the phone number to your ISP or whatever host you are calling. Then click the
Next button.

8 Installation
5. Click on the Finish button. A new icon is created in the Dial-up Networking folder.
6. Right click on the new icon. Then select Properties from the menu.
7. Make sure your Comet modem appears in the Connect Using field. Then click on
the Server Type Tab.

Installation 9
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 Log on to network.
• If you are logging on to a Microsoft Windows network, select NetBEUI.
• 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 option button and enter your IP address. If your host

10 Installation
assigns an IP when you log in (Dynamic IP), then leave the Server assigned IP
address option button checked. Most servers assign an IP to you when you log in.
8. Click the Specify name server addresses option 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.
If the User name and Password are incorrect or missing, type them in. Click on the
Connect button and your Comet will dial the number and establish a connection to your
Internet Service Provider.
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Setup for DOS Fax/Modem Software
After installing the Comet, 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. Select the following communication settings:

Installation 11
Setting Value
Baud rate 115,200bps
Data bits 8
Parity None
Stop bits 1
Flow control Hardware
Initialization string AT&F
Port COMn*
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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 TR 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.
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
contact ZyXEL technical support.

12 Basic Modem Operation
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 Comet up
and running with communication software, and to start making connections with your
Comet.
Understanding AT Commands
The Comet communicates asynchronously with computers using AT commands. AT
commands are used to configure and control the Comet. Commands are usually sent to
the modem by way of communication software, but can also be entered manually with
the computer keyboard.
Command statements must be written in a specific form in order for the Comet 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 Comet is in “command mode” or “off-line.”
Once the Comet 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 Comet by your computer
are transmitted to the remote modem rather than being interpreted by the Comet 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 Comet, or store phone numbers you will commonly
connect to.
Once the Comet 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 Comet 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 Comet should be
as follows:
Bits per second: 115200

Basic Modem Operation 13
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>
Comet 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 Comet 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: ATDT555 1212
Pulse Dialing: ATDP555 1212
Tone and Pulse Dialing: ATDP555 1212 WT24
Pausing During Dialing: ATDT 9,,555 1212
Dialing Without Waiting for Dial Tone: ATX0D, 555 1212
Originating a call using an Answer Tone: ATDT 555 1212,,,,,,R