ZyXEL U-336R, U-336RE User Guide

U-336R/RE

User’s Guide

Version 1.0

(Mar. 1997)

ZyXEL

ACCESSING INTERNET & INTRANET

ZyXEL 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 discretion, 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 re-manufactured functionally equivalent product of equal value, and will be solely at the discretion 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 out-dated warranty will be repaired or replaced (at the discretion 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 the U.S. borders, the customer shall bear the cost of the return shipment. This warranty gives you specific legal

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rights, and you may also have other rights which vary from state to state.

Copyright ©1997 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 Corporation. All rights reserved.

Note: 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.

Acknowledgments

Trademarks mentioned in this manual are used for informational purposes only.

Trademarks are properties 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 A digital device pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy,

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and if not installed and used in accordance with the instructions, may cause harmful interference to radio communications.

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.

Information for Canadian Users

The Industry Canada label identifies certified equipment. This certification means that the equipment meets certain telecommunications network protective, operation, and safety requirements. The Industry Canada 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

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company’s inside wiring associated with a single line individual service may be extended by means of a certified connector assembly. 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.

This digital apparatus does not exceed the class A limits for radio noise emissions from digital apparatus set out in the radio interference regulations of Industry Canada. The declarations of CE marking:

This product has been approved for connection to the Public Switched Telecommunication Network using interfaces compatible with ITU-TSS recommendation I.420. This product complies with the following directives:

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1.The Council Directive 89/336/EEC of 3 May 1992 on the approximation of the laws of the member states relation to Electro Magnetic Compatibility. (EMC Directive)

2.Council Directive 91/263/EEC of 29 April 1991 on the approximation of the laws of the Member States concerning telecommunication terminal equipment. (The Telecom Terminal Equipment Directive)

3.93/68/EEC of 22 July 1993 amending the Directives 89/336/EEC, 91/263 /EEC and 92/31/EEC.(Marking Directive)

The Council Directive 92/31/EEC of 28 April 1992 amending directive on the approximation of the laws of the member states relating to electromagnetic compatibility.

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]

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: [e-mail] in North America. [e-mail] outside North America.

∙Technical support: [e-mail] in North America. [e-mail] outside North America.

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∙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 and Asian versions and related files, use the address: ftp.zyxel.co.at

∙Postal Service: You can send written communications to the following address:

ZyXEL Communications Corporation

6, Innovation Road II, Science-Based Industrial Park Hsinchu, Taiwan 300, R.O.C.

or

ZyXEL Communications Inc. 4920 E. La Palma Avenue Anaheim, CA92807, U.S.A.

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Contents

ZyXEL Limited Warranty ii

FCC Part 15 Information iii

Information for Canadian Users iv

Contacting ZyXEL vi

1 Introduction 1

What This Manual Covers 1

Modem Features 1

Standard Features 1

Intelligent Features 2

Fax Compatibility 3

Technical Specifications 3

Unpacking Your Modem 4

Enclosed Equipment 4

Required Equipment 4

Becoming a Registered Owner 5

2 Installation 7

U-336R/RE Modem Card 7

Required Steps for U-336R/RE Installation 9

Installing the modem card 10 Connect to phone lines 10 Connect to Computers 11 Hooking Up Power 11

Fax/Modem Communication Software Installation 11

3 Basic Modem Operation 15

Understanding AT Commands 15

Using the Windows 95 Hyper Terminal Program 15

Dialing and Answering Techniques 17

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Dialing using the ATD Command 17 Auto-Answer and Hook Controls 18

Making Your First Connection 18

Quick Tips when issuing AT Commands 19

Modem Result Codes 21 Viewing S Register Values 22 Changing S Register Values 22

Non-Volatile Memory 23

Storing Phone Numbers 23 Dialing Stored Phone Numbers 23

Saving Settings and User Profiles 24

Helpful Hints for PC Computers 24

Default Modem Settings for PC’s 25 ZyXEL Serial/Parallel I/O Card 25

Helpful Hints for Macintosh Computers 26

Special AT Command Settings for Macintosh 26 Macintosh Serial Port 26

Mac Software Tips 26

Helpful Hints for UNIX-Based Computers 27

Serial Cable 27

Basic Modem Settings for UNIX 27 Unix Software Tips 28

4 Synchronous Mode Operation 29

V.25bis Command Set 29 Clock Options 30

RTS Options 31

Command State Options 32 Dialing from Synchronous Mode 32

Answering from Synchronous Mode 33

Auto-Answer 33 Manual Answer 33

5 Leased Line Operation 35

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Connecting to a Leased Line 35

Line Type Setting 35 Power Level Setting 36

Leased Line Handshaking 36

Manual Connect 36

Auto Handshake 36

Leased-Line Dial Backup 37

Dial Backup 37

Aborting from Leased-Line Operation 38

Terminating a Leased Line Connection 38

6 Special Functions 39

Security Functions 39

Levels of Security 39

User Passwords 40

Remote Configuration 42

Caller Number Delivery (Caller ID) 43

Distinctive Ring 46

Extended Distinctive Ring (EDR) 47

Setting Up EDR 49

EDR Application Example 50

7 Fax Operation 53

Modem as Fax Machine 53

ITU-T T.30 Fax Protocol 54

Fax Command sets 54

Defining the Fax Command Sets 54 Class 1 Command Set 55

Class 2 Command Set 56

Class 2.0 Command Set 63 Extended Fax AT Command Set 70 Flow Control 74

Fax Reception from a BBS 75

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8 AT Command Set Summaries 77

Basic AT Command Set 77

Description of ATI2 Output: 80

Extended AT& Command Set 83

Extended AT* Command Set 89

9 Status Registers & Result Codes 92

S-Register Descriptions 92

Basic S-Registers "ATSn=x" 92 Extended S-Registers "ATSn=x" 93

Result Code Options 111

"ATXn" Result Code Option Table 111 Result Code Field Descriptions 113

Connect Strings for Error Corrected Connections 113

10 Diagnostics & Troubleshooting 116

Diagnostics 116

Power-On Self Test 117

Loopback Tests 118

Indicator Lights 119

Line Condition Status Display 120

Link Status Report (ATI2) 122

Trouble Shooting 126

AT Command Set Problems 126

Command Echo Problems 128

Answer Problems 128

Dialing Problems 129

Data Transfer Problems 130

Connect Problems 130

11 Upgrading Your Modem 131

Upgrading by Flash EPROM 131

Kernel Recovery Mode 132

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12 Terminal Pinouts 133

Terminal Blocks 133

PC Serial Port Pinouts 134

Macintosh Serial Port Pinouts 135

13 Index 137

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1 Introduction

What This Manual Covers

Congratulations on the purchase of your U-336R/RE modem - one of ZyXEL's premier high-performance products. The U-336R/RE modem cards are world renown for their ability to maintain ultra high speeds and clear, quality connections while communicating around the globe.

Modem Features

No other 33.6 Kbps modem gives you so much for so little. Your modem is equipped with an array of standard and Intelligent features designed to make your data communications faster, easier, and more convenient.

Standard Features

∙Supports V.34 for 28,800bps and is backwards compatible.

∙Operates in all environments including: 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.

Introduction 1

∙14 LED indicators (RE/RD).

∙15 LED indicators (R).

∙Extended AT command set with V.25bis.

∙Operates on 2-wire dial-up or 2-wire leased line (RE).

∙Operates on 2-wire dial-up or 2/4-wire leased line (R).

Intelligent Features

∙Automatic data, and fax call detection allows you to use a single telephone line to handle both voice and data calls.

∙Asynchronous and synchronous modes for reliable serial data communication.

∙Fast retrain with automatic fall-forward and fall-back. Your modem 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 modem 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.

2 Introduction

∙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.

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.

Introduction 3

∙Line interface: 2-wire dial-up or 2-wire leased line (RE).

∙Line interface: 2-wire dial-up or 2/4-wire leased line (R).

∙Call progress monitoring: dial tone, busy, and ring back detection.

∙Audio Monitor: programmable volume control.

Unpacking Your Modem

Enclosed Equipment

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

∙One U-336R/RE universal modem.

∙One 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 see page vi to contact ZyXEL.

Required Equipment

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

4 Introduction

∙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 and fax communication software.

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. Also save your dated invoice as proof of purchase.

Introduction 5

6 Introduction

2 Installation

This chapter covers the steps required to install your U-336R/RE modem into a ZyXEL RS-1612 rack system. A separate comprehensive manual containing rack system information is included with your modem rack chassis.

U-336R/RE Modem Card

The U-336R front panel consists of fifteen LED indicators and two switches. The U-336RE front panel consists of fourteen LED indicators and two switches. The LEDs on the front panel, display the current status and configuration of the modem. Refer to the following table for details on the LED status indicators and their meaning.

	LED	Name	ON		Blinking
	PWR	Power Indicator	The modem is on
			and operational.
	TST	Test Indicator	The modem is in test
			mode.
	V34	V.34 Mode	The modem is		The modem is
		Indicator	operating in V.34		in
			mode.		Handshaking
					state.

Installation 7

	LED	Name	ON	Blinking
	TXD	Transmit	The DTE is sending
		Indicator	data to modem for
			transmission.
	RXD	Receive	The modem is
		Indicator	sending received
			data to the DTE.
	CD	Carrier Detect	The modem senses a
			valid data carrier on
			the line.
	DTR	Data Terminal	The attached
		Ready	computer is ready to
			send or receive data.
	DSR	Data Set Ready	The modem is ready
			to send or receive
			data.
	RTS	Request to Send	The DTE requests
			to send data for
			transmission.
	CTS	Clear to Send	The modem is able
			to accept data for
			transmission.
	OH	Off Hook	The modem is in
		Indicator	Data Mode or Off
			Hook.
	ORG	Originate Mode	Modem is in
		Indicator	Originate Mode.
	RI	Ring Indicator	Modem is in Auto-	Modem
			Answer mode.	detected an
				incoming call.

8 Installation

	LED	Name	ON	Blinking
	SQ	Signal Quality	Modem senses a	Modem
			good quality signal.	senses
				marginal
				signal quality.

The following LED is for the U-336R only:

	LED	Name	ON	Blinking
	LL	Leased Line	Modem is in Leased
		Mode Indicator	Line Mode.

There are two toggle switches on the U-336R/RE front panel.VOICE/DATA Toggles the modem on-line (off-hook, DATA) or off-line (on-hook, VOICE mode, the telephone set is connected to the line). ANS/ORG switches the modem between ANSWER and ORIGINATE modes when the modem goes off hook.

ONOTE: THE ANS/ORG SWITCH ONLY DETERMINES MODEM ON-LINE MODES WHEN THE MODEM IS SET TO OFF-HOOK MANUALLY. IF ATD OR ATA COMMANDS TAKE THE MODEM OFF HOOK, THOSE COMMANDS WILL DETERMINE THE OPERATING MODE FOR THE MODEM TOO.

Required Steps for U-336R/RE Installation

Setting up the rack system consists of plugging in modem cards, connecting phone lines, connecting to computers, and connecting power. Refer to your rack system User’s Guide for details on setting up the rack.

Installation 9

Installing the modem card

The rack system in which you will install your modem has sixteen available modem slots. You may use any slot for a card without regard to the slot number or sequence. To install a card:

1.Hold the modem card by the front and slide it into an available slot.

2.Push the card gently but firmly until it seats.

3.Screw the modem card holding screws into place to secure the card in its slot.

ONOTE: THE MODEM CARD WILL NOT SEAT AND THE HOLDING SCREWS WILL NOT TIGHTEN IF YOU INSTALL THE MODEM CARD UPSIDE DOWN.

Connect to phone lines

Sixteen terminal blocks correspond to the sixteen modem card slots in the rack. Each offers you flexibility with respect to the types of phone lines you may be using. Each terminal block has three sections:

∙U-336RE Section 1 (terminals 1 & 2) For standard telephone set connection.

∙U-336R Section 1 (terminals 1 & 2) For standard telephone set connection.

∙U-336RE Section 2 (terminals 3 & 4) For dial-up line and 2W leased line connection.

∙U-336R Section 2 (terminals 3 & 4) For dial-up line.

∙U-336RE Section 3 (terminals 5 ,6 ,7 & 8) Not used.

10 Installation

∙U-336R Section 3 (terminals 5 ,6 ,7 & 8) For leased line connection.

Connect to Computers

Each modem slot has a corresponding 25-pin RS-232 female connector on the rear panel. Connect a cable from the desired computer to the RS-232 connector for the desired modem.

Hooking Up Power

Connecting power should be the last thing you do before using the rack. To connect power follow the instructions below:

1.Plug one end of the power cord to the socket on the back panel.

2.Plug the other end to a properly rated power source.

3.Switch the power source selector to AC or DC according to the type of power supply(s) you are using.

4.Make sure all other hardware installations are complete.

5.Unscrew the front panel and turn on one or both power supply(s).

6.Replace the front panel.

7.Turn on the master power.

Fax/Modem Communication Software Installation

After completing installation of your modem 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 your modem is not one of the choices, you can either check our web site for the driver or select the ZyXEL U-

Installation 11

1496 modem. In many cases, the commands for these modems are identical.

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	COMn*

ONOTE: 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.

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

4.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.

5.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 0 for troubleshooting suggestions.

6.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

12 Installation

10 for troubleshooting suggestions.

Installation 13

14 Installation

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 up and running with communication software, and to start making connections with your modem.

Understanding AT Commands

The U-336R/RE communicates asynchronously with computers using AT commands. AT commands are used to configure and control your modem. 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 your modem 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 your modem is in “command mode” or “off-line.”

Once your modem 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 your modem by your computer are transmitted to the remote modem rather than being interpreted by your modem 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 Microsoft Windows “Hyper

Basic Modem Operation 15

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 modem, or store commonly used phone numbers.

Once your modem 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 modem is connected to from the “Connect Using” list. Click “OK” when finished.

The next window sets the COM port settings. The settings used for your modem should be as follows:

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>

16 Basic Modem Operation

Your modem 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>

Your modem 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 tone 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
ONOTE:	THE 'W' IN THE DIAL STRING WILL CAUSE THE MODEM TO WAIT FOR A SECOND
	DIAL TONE BEFORE IT CONTINUES TO DIAL.

Basic Modem Operation 17

	Pausing During Dialing:	ATDT 9,,555 1212
ONOTE:	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
ONOTE:	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.

18 Basic Modem Operation