ZyXEL Communications TA128 User Manual

Omni TA128

User’s Manual

Version 2.0

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

ii

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 B 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,

iii

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.

The declarations of CE marking:

The TA128 has been approved for connection to the Public
Switched Telecommunication Network using interfaces compatible
with ITU-TSS recommendation I.420 (Basic Rate ISDN user
access). The TA128 complies with the following directives:

iv

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)

4. Council Directive 73/23/EEC and 93/68/EEC of 26 Dec 1996 on

the harmonization of the laws of the Member States relation to
electrical equipment designed for use within certain voltage
limits.

5. The Council Directive 92/31/EEC of 28 April 1992 amending

directive on the approximation of the laws of the member states
relating to Electro Magnetic 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.

v

• Technical support: [e-mail] in North America

[e-mail] 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, R.O.C.
or
ZyXEL Communications Inc.
4920 E. La Palma Avenue
Anaheim, CA92807, U.S.A.

vi

Table of Contents

ZyXEL Limited Warranty...........................................................ii

FCC Part 15 Information............................................................iii

Contacting ZyXEL.......................................................................v

1 Introduction ......................................................................1

Key Features of the TA128..........................................................2

Speed and Compatibility.............................................................2

Intelligent Features.......................................................................2

Technical Specifications..............................................................3

Physical Characteristics...............................................................3

U-Interface Option.......................................................................4

Unpacking Your TA128...............................................................4

How to Become a Registered Owner...........................................4

2 Installing your TA128 .......................................................5

Back Panel of the TA128..............................................................5

Connecting Your TA128 to the Power Supply..........................6

Connecting the TA128 to Your Computer.................................6

Connecting the TA128 to your Computer Serial Port...............7

Connecting the TA128 to Your ISDN Line................................8

U Interface Model........................................................................8

S/T Interface.................................................................................9

Power On and Self Diagnostics...................................................9

TA128 Front Panel......................................................................10

The LED Indicators....................................................................10

Front Panel Switch.....................................................................11

3 Configuring Your ISDN Line and Network....................13

Configuring Your TA using a Configuration Utility..............13

vii

Configuring your TA using a Terminal program...................14

4 ISDN Communication Basics ........................................17

Understanding AT Commands.................................................17

Supported AT command types:................................................18

Quick Tips when issuing AT commands:.................................18

Outgoing Calls .............................................................................19

Dialing out using ISDN mode...................................................19

Dialing out using ISDN mode’s optional Speech Bearer Service

.....................................................................................................19

Dialing out for Analog Adapter Port 1......................................20

Dialing out for Analog Adapter Port 2......................................20

Manually switching communication modes ............................20

Placing the Call...........................................................................21

Incoming Calls.............................................................................21

Digital Data.................................................................................22

Determining the Packet Length.................................................22

Answering a Call using MSN....................................................23

Data over Speech Channel........................................................24

Best-effort call answering..........................................................25

Ambiguity resolution switch for voice calls.............................25

Multi auto-answering of data calls............................................26

5 Setup for Windows 95 and NT 4.0.................................27

Installing the Windows 95 Driver (INF file)...........................27

Configuring Windows 95 Dial-Up Networking.......................31

CAPI Installation.........................................................................35

6 Point-to-Point Protocol (PPP)........................................37

Introduction..................................................................................37

Feature list....................................................................................38

Async to Sync Conversion........................................................38

Authentication conversion ........................................................39

Compression Control Protocol (CCP)......................................40

viii

Multilink PPP .............................................................................40

Call bumping..............................................................................41

Bandwidth On Demand (BOD) ................................................42

BACP/BAP.................................................................................42

7 V.110 and Synchronous Mode Communications.........45

Answering a V.110 call...............................................................45

Making V.110 Calls.....................................................................46

Synchronous Connections..........................................................46

V.25bis Command Set...............................................................47

DTR Drop-Dialing Operation....................................................48

8 V.120 ISDN Communications.........................................51

Placing outgoing calls.................................................................51

Configuring the V.120 mode.....................................................52

Dialing in V.120 mode...............................................................53

Answering incoming calls..........................................................53

Speeds of 128Kbps......................................................................54

Identifying your line provisioning.............................................54

Making a Bundled Call with V.120...........................................54

Dialing pre-stored phone numbers ...........................................55

Error Correction and Data Compression with V.120............56

Bundle Connection with V.42bis Data Compression..............57

Selecting V.120 for European ISDN (DSS1) ...........................57

Selecting V.120 for Germany National ISDN (1TR6)............58

9 X.75 ISDN Communications (Europe)...........................59

Answering an X.75 call...............................................................60

Making an X.75 Call ...................................................................60

Making a Bundled Call with X.75.............................................61

Dialing Pre-stored Phone Numbers..........................................62

Invoking V.42bis Data Compression .......................................62

Bundle Connection with V.42bis Data Compression..............63

ix

10 Handling Analog Calls .................................................65

Placing a Call from the Analog Adapter..................................66

Accepting an Incoming Call.......................................................67

Feature Phone..............................................................................69

The Flash key.............................................................................69

InterCom ....................................................................................70

Call Waiting................................................................................70

Placing a second call..................................................................70

Receiving a second call..............................................................70

Call Broker..................................................................................71

Call Reject..................................................................................71

Call Transfer...............................................................................72

Three-way Conference Call.......................................................72

11 Advanced ISDN Call Control .......................................74

Call Control for DSS1 (Digital Subscriber Signaling #1)......74

Control of Outgoing Service Indicator .....................................74

Control of ISDN Phone Number and Sub-address.................76

Call Control for 1TR6 (Old German ISDN)............................77

Control of Outgoing Service Indicator .....................................78

Control of ENDGERÄTEAUSWAHLZIFFER (EAZ)............78

Answering a Call .........................................................................80

Answering a Call for DSS1 .......................................................80

Answering a Call for 1TR6........................................................81

Best-effort Call Answering........................................................82

Ambiguity Resolution Switch for Voice Calls.........................82

Multi-Auto-Answering of Data Calls........................................82

Data Call Indication...................................................................83

Disable inbound call connection...............................................84

Point-to-Point Configuration.....................................................84

Placing a Call................................................................................84

Placing a call for DSS1 ..............................................................85

Placing a call for 1TR6...............................................................86

x

Leased Line ISDN.......................................................................86

12 Security Functions.......................................................88

Security Types and Levels .........................................................88

Level 1 security..........................................................................89

Level 2 security..........................................................................89

Level 3 security..........................................................................89

Setting and Modifying Passwords............................................90

Non-password Auto Call Back Function .................................91

13 Upgrading Your TA128.................................................94

Upgrading with Flash EPROM................................................94

Kernel Mode...............................................................................95

14 DTE Port 2.....................................................................96

Selection of the Two DTE Port Mode.......................................96

Configuring DTE Port 2.............................................................97

Basic "AT" Command Set.........................................................98

Extended "AT&" Command Set.............................................101

Setting of DTE port 2 Speed ...................................................102

DTE Port 2 Call Control...........................................................103

15 Diagnostics.................................................................104

Diagnostics .................................................................................104

Power-on Self-test....................................................................104

ISDN Loopback test (AT&T9)................................................105

Loopback with Self-test (AT&T10)........................................105

B1/B2 Loopback with Self-test (AT&T11).............................105

The Diagnostic Command (ATCG)........................................106

Resetting The TA128................................................................107

Using The Embedded Protocol Analyzer...............................107

Capturing the Protocol Data....................................................108

Analyzing the Captured Data..................................................109

16 AT Command Set Reference......................................112

xi

Operation Modes of the DTE Interface..................................112

Simplex mode..........................................................................112

Multiplex mode........................................................................112

AT Command Descriptions .....................................................113

Basic "AT" Command Set.......................................................114

Description of ATI3 Output:...................................................121

Extended "AT&" Command Set.............................................122

Extended "AT*" Command Set..............................................127

17 Status Registers and Result Codes..........................130

Viewing and Setting S-Registers.............................................130

Viewing S-registers..................................................................130

Setting S-registers ....................................................................131

S-Register Descriptions............................................................133

Basic S-Registers "ATSn=x"...................................................133

Extended S-Registers "ATSn=x"............................................133

"ATXn" Result Code Option Table........................................152

Result Code Chart Symbol Reference....................................154

Result Code Field Descriptions...............................................154

Connect Strings for Error Corrected Connections.................155

18 Phone Jack Pinout Assignments..............................156

19 Serial Port Interface...................................................158

xii

1 Introduction

Congratulations on your purchase of a ZyXEL Omni TA128. The
TA128 sets new price/performance standards for the explosively
growing Internet and telecommuting applications market.

When used with off-the-shelf Internet or remote access client
software, the TA128 enables mobile or home users to connect to
the Internet or branch offices over ISDN lines Hassle Free! The
same device also allows a user to connect to the analog world via a
modem, fax machine, or telephone connected directly to the
TA128.

To take advantage of constant new developments, the TA128
employs flash EPROM, which allow for convenient uploading of
newly available firmware, preserving your hardware investment.

The TA128 supports both D and B Channels protocols. For the D
Channel, it supports DSS1, 1TR6, DMS-100, AT&T Custom, and
NI-1. For the B Channels, X.75 SLIP, V.120, V.110, PPP Async-to­sync Conversion and Bundle (128Kbps).

ZyXEL’s expertise in data compression has been brought to the
TA128. With its V.42bis compression on the B Channels using
either X.75, V.120, or STAC/LZS compression over PPP/MP the
TA128 can effectively communicate at speeds up to 460Kbps over
ISDN lines.

The TA128 also has two analog ports for handling fax machines,
modems, and telephones. Two different analog devices can
communicate over the two B channels to two different locations
simultaneously, so you can send a fax and make a voice call at the
same time. The analog ports also recognize standard DTMF tones
as well as pulse dialing.

1

Key Features of the TA128

Speed and Compatibility

• Plug and Play support for Win95 environment.

• Full compatibility with both ISDN and remote PSTN via ISDN.

• Supports leased line operation.

• Multiple signaling protocol compatibility with the following

network switches: DSS1, 1TR6, NI-1, AT&T 5ESS, and
Northern Telecom DMS 100.

• Supports X.75, V.110, V.120, and PPP Async-to-Sync

Conversion B Channel protocols.

• B Channel speeds of 56Kbps(in-band Signaling) and 64Kbps

(out-of-band Signaling).

• 112Kbps/128Kbps channel bundling: MLP, CCB, and Multilink

PPP(RFC1661).

• V.42bis data compression using the X.75, V.120, and Bundle

protocols.

• STAC data compression using PPP/MP

• Two application program interfaces:

• ZyXEL ISDN AT Commands

• CAPI 1.1a and CAPI 2.0.

Intelligent Features

• Automatic ISDN/analog call detection.

• Feature Phone operation, including call back, broker, and three-

way conferencing.

• Two independent DTE ports:

• DTE Port #1

2

Asynchronous: Auto Baud Rate up to 460.8Kbps
Synchronous: Configurable Rate up to 128Kbps

• DTE Port #2

Asynchronous: Data Rate up to 115.2Kbps

• Two analog telephone jacks (analog adapters) with metering

pulse function.

• Built-in internal speaker with volume control.

• Push-button switch for quick dial and tear down.

• Call-back security with password protection.

• Flash EPROM memory for easy firmware upgrades.

Technical Specifications

• Status Display: 10 LED indicators.

• Flow Control: Software XON/XOFF or hardware CTS/RTS.

• Configuration Setting: Software programmable with

nonvolatile memory for profile storage.

• Diagnostics: Self and loopback tests.

Physical Characteristics

• Line Interface
RJ-45 for S/T or U interface, RJ-11 for phone connection.

• DTE Interface
DB-25 connector for DTE Port 1.
DB-9 connector for DTE port 2.

• Weight (g)
383

• Dimensions (cm)
L-18.1 x W-13.5 x H-3.7

3

U-Interface Option

For North American ISDN, ZyXEL provides an optional 2B1Q U­interface which allows direct connection to the network without the
use of an external NT-1 device.

Unpacking Your TA128

Your TA128 should come with the equipment listed below. If any
item is missing or damaged, contact your dealer or ZyXEL
Customer Service Department immediately.

1. One (1) TA128 ISDN Terminal Adapter.

2. One (1) power adapter.

3. Two (2) RJ-11 telephone cables.

4. One (1) RJ-45 ISDN telephone cable.

5. One (1) 6' shielded RS-232 25-pin to 25-pin cable.

6. One (1) 3.5" driver and utility disk.

7. One (1) warranty/registration card.

8. One (1) TA128 User's Manual.

How to Become a Registered Owner

Complete the pre-addressed registration card and place it in the
mail. Registered owners will receive future product information and
update announcement. Save your dated invoice as proof of
purchase.

4

2 Installing your TA128

Back Panel of the TA128

You will find the following switch and connectors on the back
panel of the TA128: See the figure below:

ON/OFF - Power switch; turns the TA128 ON or OFF.
POWER - Input terminal for power adapter.
To DTE 1 - Serial port DB25 female connector for connection to

the serial port of a DTE (computer/terminal).
To DTE 2 - Serial port DB9 female connector for connection to the

serial port of a DTE (computer/terminal).
ISDN - ISDN RJ-45 terminal jack; connects to a S/T interface or a

U interface (depending on the TA128 model purchased).
PHONE 1 - RJ-11 terminal jack for analog adapter 1; for

connecting to analog equipment. (phone, fax, answering machine,
etc.)

PHONE 2 - RJ-11 terminal jack for analog adapter 2; for
connecting to analog equipment.

OO NOTE: The signal-pin assignment of the RJ-45 and RJ-11 phone jacks

are listed in Chapter 18 .

Figure 2 -1 TA128 Back Panel

5

Connecting Your TA128 to the Power
Supply

To Connect your TA128 to the power supply, follow the steps
given below:

1. Turn off your computer.

2. Make sure the power switch on the TA128 is in the OFF

(down) position.

3. Connect the round end of the power adapter to the POWER

JACK on the TA’s back panel.

4. Plug the power supply unit to an AC wall jack then power on

the TA128.

5. Observe the LED light status on the front panel of your TA128

and make sure PWR LED is on.

OO NOTE: Use only the power adapter supplied with your TA. Never use a

power adapter designed for a different product.

Connecting the TA128 to Your Computer

Your TA128 comes with a 25 pin, male to female cable, which is to
be used to connect the main serial port of TA128 to your computer
serial port as seen in the figure below:

6

Connecting the TA128 to your Computer Serial Port

Figure 2 -2 Connecting the TA128 to Your Computer

Complete the following steps to connect the TA128 to your
computer:

1. Turn off the power to your computer.

2. Connect the male end of the 25 pin cable to serial port1.

3. Connect the other end of the cable (female end) to your

computer’s serial port. In case your computer only supplies a 9
pin serial connector, you will need to use a 25 pin to 9 pin
converter (9 pin female to 25 pin male). If you have another
type of serial port connector, such as on the Macintosh, you
will need a special cable for the connection.

4. Once the connection is made, turn the computer back on.

7

Connecting the TA128 to Your ISDN Line

The TA128 comes with a choice of two types of ISDN line
interfaces:

• S/T interface - This can only connect to your NT-1 (Network

Termination) device.

Warning:Do not under any circumstances connect directly to the ISDN

wall jack.

• U interface - This allows you to connect directly to your ISDN

wall jack.

Warning:The ISDN jack is for ISDN line connection only. Connection of a

phone line may result in damage to your Terminal Adapter.

Attention: La fiche ISDN est destinée uniquement pour la connexion

sur une ligne RNIS. La connexion sur une ligne téléphonique
peut endommager votre adaptateur de terminal.

U Interface Model

If you have purchased the TA128 U-interface model, you can
connect the U-Interface directly to the wall jack.

In most cases, the ISDN jack installed by the phone company is a
RJ-11 jack (except in Canada, where RJ-45 jack will be installed),
and the U-Interface jack on the back of the TA128 is a RJ-45 jack.
A RJ-45 to RJ-45 (or RJ-11 to RJ-45, depends on your regional
distributor’s request) phone cable is included with your TA128.

To connect the TA128 to your ISDN line:

• Connect the RJ-45 connector to the “ISDN U” jack on the

back of the TA128.

• Connect the other end of the RJ-45 cable (or RJ-11) to your

wall jack.

8

S/T Interface

If you have purchased the TA128 S/T model, you will need an NT­1 device to connect to the network.

Figure 2 -3 Hooking Up an NT-1 Device

Power On and Self Diagnostics

Once you have completed all of the installation steps above, flip the
TA128’s On/Off switch to the ON (up) position.

The unit should cycle through a self test sequence, where you
should see a series of LED lights blinking (LED, B1, B2, AA). After
this cycle is complete, the PWR light should stay on.

If the test routine fails, the LNK LED flashes. Refer to Chapter 15 ,
for more information on self-tests and error codes.

If you have a communication program loaded and active
(connected to the same serial port as the TA128), you should see
the DTR LED should be ON after the self test.

9

TA128 Front Panel

Figure 2 -4 TA128 Front Panel

The LED Indicators

PWR - The power on LED lights up when the TA128's power is

turned ON.
LNK - The Link LED lights up when the link with the local switch

is active and flashes when attempting to make a connection.
B1 - The B1 channel connection LED lights up when the B1

channel is established.
B2 - The B2 channel connection LED lights up when the B2

channel is established.
AA - The auto-answer LED lights up when the TA128 is in Auto

Answer mode and flashes when it rings.

10

DTR - The data terminal ready LED lights up when the DTE or
computer connected to the DTE Port indicates that it is ready for
communication by raising the corresponding RS-232 signal.

TX - The transmit data LED flashes when the DTE/Computer is
transmitting data to the DTE Port of the TA128.

RX - The receive data LED; lights up when the DTE/Computer is
receiving data from the DTE Port of the TA128.

Phone 1 - The phone 1 LED lights up when the POTS port 1
telephone/handset is off-hook.

Phone 2 - The phone 2 LED lights up when the POTS port 2
telephone/handset is off-hook.

Front Panel Switch

When the TA128 is in command state, pressing the front panel
button causes it to dial the default phone number pre-stored in the
NVRAM. The default number pointer to the telephone directory is
assigned by the AT*Dn command.

When the TA128 is on-line, pressing the button will tear down the
connection and bring it into command state.

To restore the TA128 to its factory default settings and initiate the
loop-back test, turn the power ON while pressing and holding the
switch. Continue holding the switch for 3 to 5 seconds after turning
the power ON.

11

12

3 Configuring Your ISDN

Line and Network

The set up procedure for the TA128 needs to be done only once.
The settings will be stored in non-volatile RAM. The only time you
will need to reconfigure your line is when you perform a hardware
reset on your TA or when you change options on your ISDN line.

There is a simple Windows 3.x, NT4.0 or 95 utility provided by
ZyXEL to help you set-up the TA128. We will explain how to
setup your switch using a Windows/Windows 95 utility which
comes with the TA128.

If your TA128 is not going to be set up by a computer running
Windows, you will need some type of terminal program that allows
you to send AT commands to the TA and receive responses from
the TA.

Configuring Your TA using a Configuration
Utility

Along with your TA128, you will find a disk labeled “ZyXEL
ISDN Configuration Manager”. Complete the following steps to
install this software:

1. Insert your ZyXEL Configuration Utility disk into the floppy

drive on your computer

2. From Windows 3.x choose Run... from the File menu.

3. From Windows NT4.0 choose Run... from the File menu.

4. From Windows 95 choose Run... from the Start menu.

5. Type: A:\setup.exe and press Enter.

6. Follow the instructions on your screen.

13

Configuring your TA using a Terminal
program

If you are not using the ISDN configuration utility that is packaged
with the TA128, you will need a terminal program with which to
configure the unit. The TA128 should work with any asynchronous
terminal program that can communicate directly with one of the
communication ports on your system. If you do not know how to
use a terminal program, refer to the instructions that came with the
terminal program.

Make sure the program is set up to communicate with the COM
port that the TA128 is connected to. You can check to see if the
DTR LED is on when the terminal program is active. In most cases,
if the terminal program is active and ready to communicate with
the port that the TA128 is connected to, it will activate the DTR
signal. This will cause the DTR LED to light up. If the DTR LED is
not ON, you will need to check the program’s settings.

The communication speed can be set to anywhere between
2,400bps and 460,800bps, but 115,200bps is a good default value.
The TA128 will automatically adjust its speed to match your
communication speed.

Once the terminal communication program is ready, you can type a
simple command to see if the TA128 responds.

Type:

AT<Enter>

TA128 should respond:

OK

Type:

ATI<Enter>

TA128 should respond:

1281

14

Type:

ATI1<Enter>

TA128 should respond:

TA128 USA: V 1.00a (Firmware version number)

7607 (Firmware checksum will change based on your firmware version)

OK

Once the TA128 accepts the commands that you typed, it is ready
to be programmed and ready to operate with your ISDN network.
If you do not receive any response from the device, go over your
installation procedures again or contact ZyXEL Technical Support.

15

16

4 ISDN Communication

Basics

In this chapter, we will cover how to initiate and receive calls over
digital lines using your TA128.

Understanding AT Commands

AT commands are used to configure and control the TA128.
Command statements are usually sent to the TA by being typed
from the computer keyboard.

Command statements must be written in a specific form in order
for the TA128 to recognize them. A command statement begins
with the letters “AT” or “at”. It is then followed by one or more
commands and then by <Enter>.

AT commands can only be issued when the TA128 is in
“command” or “off-line” mode.

Once the TA128 has established a connection with the remote
device, it goes into “on-line” mode, and the characters sent from
your computer (through the TA128) are transmitted to the remote
device.

In order to issue an AT command statement, you first need to run
your communications software and configure it to the port
connected to the TA128. Refer to your communications software
manual if this is not the case.

Once the communication terminal program is running and the
TA128 is connected:

Type:

AT<Enter>

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TA128 responds:

OK

This confirms that the TA and your computer are communicating
correctly.

Supported AT command types:

Type of AT Command Example

Basic AT (Hayes compatible). ATA
Basic AT$ (on line help). AT$
Extended AT&. AT&F
Extended AT* command. AT*I1
S-Register command. ATS0=1
S-Register bit-mapped command (set S-

Register bit 1 equal to 1).

ATS13.1=1

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

You may also browse the list by using AT$.

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&O2 and ATB02 can be combined into one line
AT&O2B02.

The TA128 processes commands from left to right. The AT
command that appears to the right might over-write the command
to the left. For example, ATB13B14 will result in ATB14 since both
B13 and B14 can not co-exist.

If you see duplicated characters for each one you type, your TA128
and software both have their echo feature turned on (the TA128
defaults to enable command echo). To eliminate the double
characters, turn off software command echo.

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