Black Box Modem 34336 User Manual

AUGUST 1999

MD885A-R2

MD885A-R3

MD885AE-R2

MD885C-R2

601745301 Rev. A

Modem 34336

34336

MODEM

ENT

NOTE

All models include the modem, (1) leased line cable, (1) dialup phone cable

and this user manual. The MD885A-R2, MD885AE-R2, and MD885A-R3

include a power supply. The MD885A-R3 also includes (1) 10-ft. RS-232

cable and (1) DB9 F to DB25 M adapter.

CUSTOMER

SUPPORT

INFORMATION

Order toll-free in the U.S.: Call 877-877-BBOX (outside U.S. call 724-746-5500)

FREE technical support 24 hours a day, 7 days a week: Call 724-746-5500 or fax 724-746-0746

Mailing address: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018

Web site: www.blackbox.com

•

E-mail: [email protected]

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Modem 34336

Table of Contents

1.0 Specifications .....................................................................................6

2.0 Quick Start..........................................................................................8

2.1 Installation ..................................................................................8

2.1.1 Unpacking ................................................................................8

2.1.2 Package Contents......................................................................8

2.1.3 What You Will Need..................................................................8

2.1.4 Connections ..............................................................................8

2.1.5 Jumpers....................................................................................10

2.2 Front Panel LCD And Controls ..............................................11

2.2.1 Power-On Screen ...................................................................11

2.2.2 EIA Status Screen ...................................................................12

2.3 Quick Setup ..............................................................................13

2.4 Basic Operation .......................................................................16

2.4.1 2-Wire Dial (Hayes) Mode .....................................................16

2.4.2 2-Wire Dial (V.25 bis) Mode ..................................................18

2.4.3 2-Wire Dial (Dumb) Mode ....................................................19

2.4.4 Leased Line (2- or 4-Wire) Mode .........................................21

2.4.5 V.33 Leased Line Operation .................................................22

2.4.6 2-Wire Dial (Bell 208) Operation .........................................22

2.4.7 4-Wire Leased Line V.29 Mode..............................................23

2.4.8 V.29 Fast Master and Slave Modes .........................................24

2.5 Problem Solving .......................................................................25

3.0 Modem Setup Options ..................................................................27

3.1 Methods For Selecting Options ..............................................27

3.2 Selecting Options From The Front Panel ..............................28

3.2.1 Pushbuttons And The LCD ...................................................28

3.2.2 How To Select Options...........................................................29

3.3 Options .....................................................................................32

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Table of Contents

3.3.1 V.42 Error Correction Options .............................................35

3.3.2 Dialer Mode ...........................................................................41

3.3.3 Data Format Options .............................................................42

3.3.4 Disconnect Options ...............................................................43

3.3.5 Test Options ...........................................................................44

3.3.6 EIA Options ............................................................................44

3.3.7 Modem Setups .......................................................................46

3.3.8 V.33 and BELL 208A/B Options ..........................................49

3.3.9 Options Accessible With Summary Setup Only ...................50

4.0 General Operation and Special Features...................................54

4.1 Quick Reset ..............................................................................54

4.2 Phone Number Storage ...........................................................54

4.3 Leased Line Auto-Recovery .....................................................55

4.3.1 Autodial Backup .....................................................................57

4.3.2 Exit From Leased Line Auto-Recovery .................................57

4.3.3 Leased Line Auto-Recovery Options ....................................58

4.4 Dial Line Auto-Recovery ..........................................................58

4.4.1 Setting Up The Modem For Dial Line Auto-Recovery .........58

4.4.2 Recovery Procedure ...............................................................58

4.5 DTR Dialing .............................................................................60

4.5.1 Dialing A Stored Number ......................................................60

4.5.2 Answer Mode Operation .......................................................60

4.6 Dumb Mode And Bell 208 Operation ....................................60

4.7 Modem Security Operation .....................................................62

4.8 Modem-Controlled Remote Control.......................................66

4.8.1 Direct Modem-to-Modem Remote Control ..........................66

4.8.2 Remote Control through a Rack Controller.........................67

4.9 Diagnostic Interface Control ..................................................71

4.9.1 Diagnostic Port .......................................................................71

4.9.2 Diagnostic Port Commands ..................................................71

4.9.3 Responses To Diagnostic Port Commands ...........................73

4.9.4 DTE Displays ..........................................................................75

4.9.5 Disconnecting From A Diagnostic Link ...............................75

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Modem 34336

4.10 Automatic Fallback ..................................................................76

4.10.1 Operating Mode Fallback ......................................................76

4.10.2 V.32 Speed Fallback ...............................................................78

4.11 V. 13 Operation ........................................................................80

5.0 Hayes Emulation Mode .................................................................81

5.1 Hayes Mode Autodialer ...........................................................81

5.1.1 Enabling The Hayes Mode Autodialer .................................81

5.1.2 Command Guidelines ............................................................81

5.1.3 Result Codes ...........................................................................84

5.1.4 Transmission Speed ...............................................................84

5.2 Hayes Compatible Commands ................................................84

5.3 S Registers ................................................................................90

5.3.1 Reading And Setting Registers ..............................................86

5.3.2 S Register Functions ..............................................................86

5.4 Selecting Options In Hayes Mode ..........................................94

5.4.1 Saving Option Selections .......................................................94

5.4.2 Profile 0 and Profile 1.............................................................94

5.5 Hayes Mode Reference Tables ................................................95

6.0 V.25 bis Autodialer .......................................................................107

6.1 Enabling The V.25 bis Autodialer .........................................107

6.2 V.25 bis Autodialer Commands ............................................108

6.3 Dialing Parameters ................................................................112

6.4 V.25 bis Result Codes .............................................................112

6.5 DTR Dialing In V.25 bis Mode ..............................................112

7.0 Diagnostics......................................................................................113

7.1 When And Why To Test ........................................................113

7.2 Symptoms And Scope Of The Problem ...............................113

7.3 Physical Inspection ................................................................114

7.4 Overview Of Modem Diagnostics ..........................................114

7.5 How To Select And Activate Tests ........................................115

7.5.1 Front-Panel Control .............................................................115

7.5.2 Running Tests In Hayes Mode.............................................115

7.5.3 Remote Test Control ...........................................................115

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Table of Conents

7.6 Diagnostic Monitoring: Status Screens .................................115

7.6.1 EIA Status Screen .................................................................115

7.6.2 Other Status Screens.............................................................116

7.7 Local Modem Diagnostics......................................................118

7.7.1 Analog Loopback (ALB) Test .............................................118

7.7.2 Analog Loopback Self Test (ALBST) .................................119

7.7.3 Analog Loopback Self Test With Errors (ST/E) ...............120

7.7.4 External Analog Loopback (ALBX) Test ...........................121

7.7.5 External Analog Loopback Self Test (ALXST)...................123

7.7.6 Digital Loopback Test (DLB) .............................................124

7.8 Remote Modem Diagnostics......................................................126

7.8.1 Remote Digital Loopback (RDL) Test ...............................126

7.8.2 Remote Digital Loopback Self Test (RDLST) ....................127

Appendix A: DB25 Pin Assignments..........................................................129

Appendix B: Quick Setup Configurations .............................................130

Appendix C: Summary Setup .......................................................................135

Appendix D: Jumpers ......................................................................................144

Appendix E: LCD Flow Charts ....................................................................147

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Modem 34336

1.0 Specifications

Available Configurations —

Compatibility —

Stand-alone or rack-mount

V.29

9600, 7200, 4800

V.32 terbo

V.33

19.2 or 16.8 kbps

14.4 or 12.0 kbps

14.4, 12.0, 9.6, 7.2, or 4.8 kbps

9.6 or 4.8 Kbps

V.32 bis

V.32

V.34+

33.6, 31.2, 28.8, 26.4, 24, 21.6, 19.2,

16.8, 14.4, and 12 kbps, 9600, 7200,

4800, and 2400 bps

V.34

28.8, 26.4, 24, 21.6, 19.2, 16.8, 14.4,

and 12 Kbps, 9600, 7200, 4800, and

2400 bps

V.22 bis

V.21

2.4 kbps,

300 bps

Bell 208A/B 4.8 kbps

Bell 212A

Bell 103

1.2 kbps

0 to 300 bps

Data Rates —

Data Format —

Operation —

Fallback —

Asynchronous: 300 to 19,200 bps

Synchronous: 600 to 19,200 bps

Asynchronous: 9, 10, or 11 bits, serial, binary

Synchronous: Serial, binary

Full duplex over dialup or leased line

Simulated half duplex V.13 operation

Data Rates: 16.8, 14.4, 12.0, 9.6, 7.2, 4.8,

2.4, 1.2, or 0.3 kbps

Operation: V.22 bis, V.22, V.21, or V.23

Supported DTE Speeds —

Modes —

300 to 115,200 bps

V.34+

33.6, 31.2, 28.8, 26.4, 24, 21.6, 19.2, 16.8,

14.4, and 12 kbps, 9600, 7200, 4800, and

2400 bps; full duplex over 2-wire line

(Trellis coded)

V.34

QAM at 28.8, 26.4, 24, 21.6, 19.2, 16.8,

14.4, and 12 kbps, 9600, 7200, 4800, and

2400 bps; full duplex over 2-wire line

(Trellis coded)

V.34 Extended AT: 33.6 Kbps, TR-301 proposed

V.32 terbo QAM at 19.2 and 16.8 Kbps; V.32bis

fallback at 14.4 Kbps and lower

V.33

QAM Trellis coded at 14.4 and 12.0 Kbps

V.32 bis QAM at 14.4, 12.0, 9.6, 7.2, and 4.8

V.32

Kbps; echo cancel, full duplex over

2-wire line (Trellis coded at 7.2 Kbps and

higher, or non-coded at 9.6 Kbps)

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1.0 Specifications

V.29

V.27

V.26

V.23

QAM at 9600, 7200, and 4800 bps

8-phase DPSK at 4800 and 2400 bps

4-phase DPSK at 2400 and 1200 bps

FSK at 1200/75 bps, full duplex

V.22 bis: QAM at 2400 bps; bandsplit, full duplex

V.22:

V.21:

DPSK at 1200 bps; bandsplit, full duplex

PSK at 0 to 300 bps; bandsplit, full duplex

Autodialer —

Automatic dialing using rotary pulses or tone

signaling; supports Hayes AT commands or

V.25 bis commands

Answer Modes —

Equalization —

Automatic and manual answer

Receiver:

Automatic adaptive equalization

Transmitter: Selectable compromise equalization

(4 types)

Line Requirement —

Transmit Timing —

Transmit Level —

Unconditioned

Internal, external, or slaved to receive clock

Leased:

Dial:

Selectable, 0 to -15 dBm

Permissive or programmable

Interface —

Terminal:

RS-232C/D, CCITT V.24/V.28

Dialup Line: 8-pin RJ-45 modular connector with

A/A1 and MI/MIC control

Leased Line: 6-pin RJ-11 modular connector

Diagnostic:

8-pin RJ-45 modular connector

Carrier Detect Threshold —

Test Capabilities —

Leased line: -26, -33, or -43 dBm; selectable

Dial line: -34, 41, or -51 dBm; selectable

Analog loopback, analog loopback self-test,

self-test with errors, digital loopback, remote

digital loo.pback self-test, external analog

loopback (4-wire), external analog loopback

self-test (4-wire); front-panel TIA/EIA or front-

panel Hayes control

AC Power —

Stand-alone: 90-132 VAC, 60 Hz 5%

Rackmount: 117/220 VAC

Power Consumption —

Heat Generation —

Ringer Equivalence —

Environment —

13 watts

44 BTU/hr

0.7 B

Ambient temp:

32 to 120°F (0 to 49°C)

Storage temp.:20 to 180°F (-7 to 82°C)

Relative humidity: 5 to 90% at 24°C (75°F)

non-condensing

Size (stand-alone unit) —

Weight —

2.5"H x 9.7"W x 10.1"D (6.4 x 24.6 x 25.7 cm)

Stand-alone:

4.1 lb (1.9 kg)

2 lb. (0.9 kg)

Rackmount:

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Modem 34336

2.0 Quick Start

All information in this manual applies to both the stand-alone and rack-

mount versions of the Modem 34336.

QUICK SETUPS FOR A QUICK START

The simplest and fastest way to set up the Modems for immediate use is to

select one of the factory-preset Quick Setup configurations.

Quick Setups are explained in Section 2.3, following installation instructions

(Section 2.1) and a brief introduction to the Modem’s front-panel display and

controls (Section 2.2).

2.1 Installation

2.1.1 UNPACKING

Many early modem failures are a result of damage done during shipping.

Visually inspect your modem. Keep the original shipping carton in case

you have to return the modem for any reason.

2.1.2 PACKAGE CONTENTS

All models include the following cables:

• A two-conductor crossover cable for a dial-line connection.

• A four-conductor cable for a leased-line connection.

Both cables have an eight-pin modular connector (RJ-45) on one end and

a six-pin modular connector (RJ-12) on the other end. You will need to use

both of the supplied cables if you want to use the Modem for Leased-Line

Auto Recovery, which requires both a leased-line and dial-line connection.

The MD885A-R2, MD885AE-R2, and MD885A-R3 include a power supply.

The MD885A-R3 package also includes additional cables:

• (1) 10-ft. RS-232 cable

• (1) DB9 F to DB25 M adapter

2.1.3 WHAT YOU WILL NEED

• You will need an EIA RS-232 interface cable (supplied with the MD885A-

R3, not supplied with the MD885A-R2, MD885AE-R2, or MD885C-R2) to

connect the Modem to a DTE (data terminal equipment, usually a

computer).

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2.0 Quick Start

• If you are operating the Modem in a manual dial mode, you also need

a standard telephone set.

2.1.4 CONNECTIONS

Figure 2-1 shows how the Modem is connected to the computer or terminal,

AC power supply, phone lines, and handset.

Do not install the modem more than 50 feet (15.2m) from the DTE (the

EIA standard maximum length for interface cable). For DTE speeds greater

than 19.2 Kbps, a shorter low-capacitance DTE interface cable should be used.

Call technical support for information on which cable will support your

application.

For all applications:

• Connect your RS-232 cable to the rear-panel DB25 connector labeled

DTE. Connect the other end to your computer or other DTE.

• Attach the power transformer cable (included) to the rear-panel

connector labeled POWER. Plug the other end into an AC outlet.

POWER

DIAL

RX LEASED

DIAL LINE PHONE

DTE

DIAG

RS-232

cable

Power

trans-

former

Dialup

Line

Leased

Line

DTE

Telephone

AC outlet

Figure 2-1. Modem 34336 Connections.

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Modem 34336

For dialup applications:

• Use the supplied two-conductor crossover cable to connect the Modem

to the telephone-line modular wall jack. Plug the eight-pin connector

(RJ-45) of the cable into the rear-panel jack labeled TX DIAL. Then,

plug the six-pin connector (RJ-12) into the telephone jack.

NOTE

Do not bundle the telephone and RS-232 cables together.

• Optional: For manual-dial operation, or if you want to use the telephone

line for voice transmissions (when the Modem is not operating in data

mode), connect a standard telephone into the rear-panel jack labeled

PHONE.

For leased-line applications:

• Use the supplied four-conductor cable to connect the Modem to your

leased-line modular wall jack. Attach the six-pin modular connector

(RJ-12) to the rear-panel jack labeled LEASED LINE. Attach the eight-pin

connecter (RJ-45) of the cable into the line’s terminal block.

The same cable is used whether you have a 4-wire or 2-wire leased line. In

a 4-wire application, the green and red wires are the TRANSMIT pair, and

the yellow and black wires are the RECEIVE pair. When the cable is

connected to a 2-wire line, only the green and red wires are used.

NOTE

Do not bundle the telephone and RS-232 cables together.

2.1.5 JUMPERS

For most applications, you will not need to reset internal jumpers. However,

jumpers must be reset for the following situations:

• If you are connecting frame ground to signal ground.

• If you are switching from A/A1 control to MI/MIC control.

• Change the function of TIA/EIA pin 25 (the default is test mode

indicator).

• If you use the Modem in a DC rack enclosure.

For detailed jumper information, see Appendix D.

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2.0 Quick Start

2.2 Front-Panel LCD and Controls

To select a Quick Setup configuration, you will need to use the pushbuttons

and liquid-crystal display (LCD) on the modem’s front panel. These features

are shown in Figure 2-2. For a detailed explanation of the front panel

controls, see Chapter 3.

2.2.1 POWER-ON SCREEN

When the Modem is powered on, the LCD momentarily displays the power-on

screen. The top line identifies the modem type. The lower line indicates the

software revision level.

NOTE

The software revision level of your modem may be different from the

number shown above.

The Modem spends about two seconds checking the ROM checksum and

doing self-tests, and then displays the EIA status screen.

V.34/33.6

Version

3.01

ENT

FRONT PANEL

PUSHBUTTONS

LIQUID CRYSTAL DISPLAY (LCD)

Figure 2-2. Front-Panel LCD and Controls.

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Modem 34336

2.2.2 EIA STATUS SCREEN

The EIA status screen indicates the operational status of the Modem as well

as the condition of certain EIA RS-232 leads. The abbreviations that may

appear are identified below. Typically, only a few of these abbreviations

will be displayed during actual operation.

D TR MR RS CS

9600

Dial line occupied.

Ringing (R appears in same position as D).

Connection secured by security handshake. (S appears in same

position as D. S and D may flash alternately).

TR = Data Terminal Ready.

MR = Data Set Ready.

RS = Request to Send.

CS = Clear to Send.

TD = Transmit Data.

14.4, 9600, 4800, etc.

or bps (bits per second) (“idle” or H-01, H-14, etc. may also be

displayed in the data speed position; see text below).

= Data speed in Kbps (thousand bits per second)

TM = Test mode.

ER = Error (poor signal quality).

CD = Carrier Detect.

RD = Receive Data.

Codes beginning with H (such as H-01) in the lower left corner of the status

screen indicate that the Modem is handshaking with another modem

(attempting to establish a connection).

When the modem is off-line, the word “idle” is displayed in the lower left

corner of the status screen.

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2.0 Quick Start

2.3 Quick Setup

To set up the Modem for immediate use (or to quickly change the modem’s

configuration for an alternate mode of operation), select one of the factory-

preset Quick Setup configurations (see Table 2-1). Your Modem will be ready

for operation. You will not need to make further adjustments.

When you select a Quick Setup, the Modem uses internal memory to

automatically set all of its options to the chosen configuration. All

previously-stored option settings are overwritten. The Quick Setup

does not affect telephone numbers stored in the modem’s memory.

You can customize a Quick Setup configuration by changing specific

option settings (see 3.0 Modem Setup Options).

HOW

SELECT A QUICK SETUP

To activate a Quick Setup configuration, follow the steps below. As you do,

you may find it helpful to refer to the LCD flow chart at the back of this

manual.

1. Press the ENT (enter) pushbutton on the modem’s front panel.

Screen 1 of the MAIN MENU is displayed:

MAIN MENU

<1>

TALK QUICK DIAL

2. Press pushbutton 2. Screen 1 of the QUICK SETUP menu appears:

QUICK SETUP <01>

2-W DIAL (Hayes)

3. Use the front-panel arrow pushbuttons to move through the QUICK

SETUP menu. There are 12 QUICK SETUP configurations. Each

configuration is discussed in Table 2-1.

4. When the LCD shows the Quick Setup configuration you want, press

pushbutton 2. The bottom line of the display will flash.

5. Press ENT. You will see SETUP screen 1. Press ENT a second time.

The modem resets and the selected Quick Setup takes effect.

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Modem 34336

All options for each Quick Setup configuration are listed in Appendix B.

If you want to customize your Quick Setup configuration, see 3.0, Modem

Setup Options. For Hayes mode options, see 5.0, Hayes Emulation Mode.

Table 2-1. Available Quick Setup Configurations.

QUICK SETUP

IDENTIFIED ON LCD

DESCRIPTION

QUICK SETUP <01>

2-W DIAL (Hayes)

2-WIRE DIAL HAYES EMULATION MODE— This

dial mode (for use over ordinary phone lines) allows the

Modem to automatically dial (autodial) a previously

stored phone number and respond to Hayes commands.

This mode is compatible with communication software

packages that use Hayes-style AT commands. The

Hayes mode Quick Setup is the factory default

configuration for the Modem.

QUICK SETUP <02>

V25 DIAL (Async)

2-WIRE DIAL V.25 bis MODE,

ASYNCHRONOUS—In V.25 bis mode, the Modem

operates in conformance with CCITT recommendation

V.25 bis, allowing you to store and direct dial or autodial

phone numbers from the DTE. Use Quick Setup 2 if the

DTE connected to the modem is asynchronous.

QUICK SETUP <03>

V25 DIAL (Syn_c)

2-WIRE DIAL V.25 bis MODE, SYNCHRONOUS-

CHARACTER ORIENTED— Same as Quick Setup 2

except for data protocol. Use Quick Setup 3 if the DTE is

synchronous-character oriented (bisynchronous).

QUICK SETUP <04>

V25 DIAL (Syn_b)

2-WIRE DIAL V.25 bis MODE,

SYNCHRONOUS BIT ORIENTED—Same as Quick

Setup 2 except for data protocol. Use Quick Setup 4 if

the DTE is synchronous bit-oriented (SDLC/HDLC).

QUICK SETUP <05>

2-W DIAL (DUMB)

2-WIRE DIAL DUMB MODE—When the Modem is in

Dumb mode, you can use it for dial-line answer-only

applications, dial a previously stored telephone number

from the front panel, or dial telephone numbers via an

external source (telephone).

QUICK SETUP <06>

2-W LEASED (ORG)

2-WIRE LEASED-LINE ORIGINATE MODE—

In Leased-Line mode, the Modem connects to the leased

line and stands ready to send and receive data. Use

Quick Setup 6 if the leased line is a 2-wire line and you

want to configure the Modem as the originate modem.

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2.0 Quick Start

Table 2-1 (continued). Available Quick Setup Configurations.

QUICK SETUP <07>

2-W LEASED (ANS)

2-WIRE LEASED-LINE ANSWER MODE—

Same as Quick Setup 6 except for modem answer/ originate

status. Use Quick Setup 7 if the leased line is a 2-wire line

and you want to configure the Modem as the answer modem.

QUICK SETUP <08>

4-W LEASED (ORG)

4-WIRE LEASED LINE ORIGINATE MODE—

Same as Quick Setup 6 except for line type. Use Quick

Setup 8 if the leased line is a 4-wire line and you want to

configure the Modem as the originate modem.

QUICK SETUP <09>

4-W LEASED (ANS)

4-WIRE LEASED LINE ANSWER MODE—

Same as Quick Setup 6 except for line type and modem

answer/originate status. Use Quick Setup 9 if the leased

line is a 4-wire line and you want to configure the Modem

as the answer modem.

QUICK SETUP <10>

4-WLL V.33

V.33 LEASED LINE OPERATION—

This Quick Setup configures the Modem for V.33

operation. This provides compatibility with V.33 modems.

QUICK SETUP <11>

2-W DIAL (208)

2-WIRE DIAL BELL 208 OPERATION—

This Quick Setup configures the Modem for 2-wire dial

operation compatible with Bell standard 208B.

QUICK SETUP <12>

2-W DIAL V32/208

2-WIRE DIAL V.32/208 AUTO-DETECT MODE—

This Quick Setup configures the Modem to automatically

select V.32 bis (V.13) or Bell 208 operation, depending on

the mode of the originating modem.

QUICK SETUP <13>

4-WLL V.29

4-WIRE LEASED LINE V.29 MODE— This Quick Setup

configures the modem for V.29 operation, for

compatibility with V.29 modems.

QUICK SETUP <14>

V.29 FAST MASTER

V.29 FAST MASTER MODE— This Quick Setup con-

figures the modem for V.29 fast train master operation, for

use in a multidrop network where multiple remote (slave)

modems share the master Modem as the host modem.

QUICK SETUP <15>

V.29 FAST SLAVE

V.29 FAST SLAVE MODE — This Quick Setup configures

the modem for V.29 fast train slave operation, for use in a

multidrop network where multiple remote (slave) modems

share the same host (master) modem.

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Modem 34336

2.4 Basic Operation

This section provides basic information for each of the modem’s primary

operating modes. If you encounter difficulty, refer to Section 2.5, Problem

Solving.

2.4.1 2-WIRE DIAL (HAYES) MODE

(QUICK SETUP 1)

Two-Wire Dial (Hayes) mode is the factory-default configuration for the

Modem. Hayes mode operation and commands are explained in detail in 5.0,

Hayes Emulation Mode.

Dialing a Phone Number. To dial a telephone number in Hayes mode,

type the Hayes command

AT D on your computer or terminal keyboard, followed by the number

you want to call and <cr>. Example:

AT D 5551212 <cr>

Dashes or spaces may be included for clarity, but they are not necessary.

The Modem ignores them.

A carriage return (<cr>) is required at the end of each command. On

most keyboards, the carriage return (<cr>) key is labeled Enter or Return.

In response to the command line shown above, the Modem will dial the

number 555-1212.

If you need an access code (such as 9) to dial out of your building,

insert the access code and a comma in the dial string:

AT D 9,5551212 <cr>

The Modem pauses for 2 seconds at the comma. This allows the Modem to

wait for a second dial tone (after the access code) before dialing the number.

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2.0 Quick Start

Dialing Mode. The default dialing mode is tone dialing. To change to pulse

dialing, insert a P after AT D:

AT DP

To change from pulse dialing to tone dialing, insert a T after AT D:

AT DT

The specified dialing mode remains active until the alternate mode is

specified or the modem is reset.

Connected. When a phone number is successfully dialed, a CONNECT

message appears on the computer screen and the LCD on the Modem

displays a status screen similar to the one shown below.

D TR MR RS CS TD

9600

TD and RD flash to indicate that the modem is transmitting and receiving

data. The speed may be other than 9600 bps. The Modem automatically

adjusts to the speed of the remote modem, provided the remote unit is a

compatible modem.

Terminating a Call. To terminate a call, first enter the escape sequence, +++.

When the OK response appears on the DTE screen, enter the command AT

H. An alternate method is to drop the DTR signal from the DTE. If you are

using a computer with a communication software program, follow the

program’s instructions for initiating and terminating calls.

2.4.2 2-WIRE DIAL (V.25 BIS) MODE (QUICK SETUPS 2, 3, AND 4)

The Modem supports three types of V.25 bis operation: asynchronous,

character-oriented synchronous, or bit-oriented synchronous. There is a

Quick Setup for each V.25 bis type.

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Modem 34336

For V.25 bis operation, the Modem must be configured to use the same data

protocol as the attached DTE. V.25 bis mode operation and commands are

explained in detail in Chapter 6.0, V.25 bis Audodialer.

Asynchronous V.25 bis Operation.

The data format of the DTE should be set to 7 data bits with even parity and

one stop bit. The default DTE interface rate is 38,400 bps in asynchronous

mode.

V.25 bis commands can be entered from the DTE keyboard. Example:

CRN 5551234

In response to this command, the Modem sends a VAL result code back

to the DTE (indicating that the command is accepted), dials the telephone

number 555-1234, and then waits for an answer tone from the remote

modem. If no carrier is detected within a given time (default is 45 seconds),

the modem automatically releases the line and sends a CFI NT result code

to the attached DTE.

Spaces entered in the command line for clarity are ignored:

CRN 555 1212 has the same effect as CRN5551212.

When a phone number is successfully dialed, the EIA status screen

on the Modem looks like the one shown below.

D TR MR RS CS

9600

Synchronous V.25 bis Operation

The data format of the DTE should be set to 7 data bits with odd parity.

In synchronous applications, the V.25 bis commands can be used to facilitate

computer-controlled operations.

Synchronous bit-oriented operation uses High-Level Data Link Control

(HDLC) formatting.

Synchronous character-oriented operation uses synchronous start-of-text

and end-of-text characters to frame messages. The start-of-text character

is preceded by two synchronous (SY) characters.

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2.0 Quick Start

2.4.3 2-WIRE DIAL (DUMB) MODE (QUICK SETUP 5)

Dumb mode is used primarily for manual call origination, answer-only

applications, and in conjunction with certain dial back security systems that

utilize MI/MIC signals to place the modem on-line. (If you need to configure

the modem for MI/MIC use, refer to Appendix D.) For additional

information on Dumb-mode operation, refer to Chapter 4.0, General

Operation and Special Features.

Answering a Call Automatically. After the Quick Setup for 2-Wire Dial

(Dumb) mode is selected, the Modem will automatically answer incoming

calls. The only other requirement is that either (1) the DTE must provide

the DTR signal (TR on the LCD status screen) to the modem, or (2) DTR

must be set to TRUE (using the modem’s DTR from EIA option screen).

Originating a Call from the Front Panel. Before you can originate a call from

the front panel, you must store the number to be dialed in the modem.

From the Set-up <5> screen, access the PHONE screen by pressing the

following pushbuttons in sequence:

Pushbutton 1 (Phone)

Pushbutton 2 (Prog)

The abbreviations DEC, CTRL, and INC are displayed on the bottom line

of the LCD, indicating that you located the PHONE screen.

Follow the steps below to store the phone number:

1. Use the right and left arrow pushbuttons to go to the digit you want to

change. The cursor causes the character at that digit location to blink,

indicating that the digit or character can be changed.

2. Use pushbutton 1 to decrease numbers, and pushbutton 3 to increase

them.

3. Use pushbutton 2 (CTRL) to sequence through the dialing control

characters (explained in Chapter 3).

4. Use the arrow pushbuttons to move on to the next digit or character

you want to change. (The characters that can be stored are listed in

Chapter 3.)

5. The phone number is saved when you return to the MAIN MENU.

To return to the EIA status screen, press ENT three times.

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Modem 34336

Autodialing the Stored Number. To autodial the stored number from

the EIA status screen, press the following pushbuttons in sequence:

ENT

Pushbutton 3 (to select DIAL from MAIN MENU screen 1)

Pushbutton 1 (to select DIAL from the AUTO-DIAL screen)

When the local modem successfully establishes a connection with the remote

unit, the EIA status screen should be present. This screen looks like the one

shown below.

D TR MR RS CS TD

9600

If the modem’s LCD displays an AUTO-DIAL FAILURE message,

refer to Table 2-2.

Terminating a Data Call. Normal termination of a data call is processed

through communication software. An alternate method is switching the

HANGUP option on the AUTO-DIAL screen. Another method is to drop

the DTR signal from the DTE (by software control or by turning the DTE off).

For manual originate/answer operation, see Chapter 4.

2.4.4 LEASED LINE (2- OR 4-WIRE) MODE (QUICK SETUPS 6, 7, 8, AND 9)

This section does not apply to V.33 leased line operation. For V.33 leased line

operation, see the next section.

Table 2-2. Auto-Dial Failure Messages.

FAILURE MESSAGE

LINE OCCUPIED

EXPLANATION

The data line is already in use.

DIAL NOT ALLOWED

Modem is not configured for dial

backup.

NO DTR

DTR is not present.

Loss of line current.

NO LINE CURR

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2.0 Quick Start

The following information applies to both 2-wire and 4-wire leased-line

operation:

• The modem must be configured for the correct line type –– 2-wire

or 4-wire. If you select the correct Leased Line Quick Setup,

the line type is automatically set to the correct setting.

• One modem must be set to originate mode and the other to answer mode.

If you select the correct Leased Line Quick Setup, the answer/originate

status is automatically set to the correct setting.

• Leased line operation is restricted to data rates of 4800 bps or higher.

• Lines can be conditioned or unconditioned.

After the appropriate Leased Line Quick Setup is selected, the answer unit

immediately begins the training sequence. It is ready to handshake with

the originate modem.

When the local modem establishes a connection with the remote unit, the

EIA status screen should be present. This screen should look like the one

shown below.

TR MR RS CS TD

9600

CD RD

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Modem 34336

2.4.5 V.33 LEASED-LINE OPERATION (QUICK SETUP 10)

V.33 operation is available on the Modem at speeds of 12,000 and 14,400 bps.

V.33 leased-line operation provides compatibility with V.33 modems

(synchronous operation only).

A 4-wire line must be used (conditioned or unconditioned), and both

connected modems must be set for V.33 operation.

After the V.33 Leased-Line Quick Setup is selected, the answer unit

immediately begins the training sequence, meaning it is ready to handshake

with the originate modem.

When the local modem successfully establishes a connection with the remote

unit, the EIA status screen is present. This screen looks like the one shown

below:

TR MR RS CS TD

9600

CD RD

Three options are intended for V.33 (and Bell 208A/B) operation exclusively.

These options are listed in Section 3.3.8.

2.4.6 2-WIRE DIAL (BELL 208) OPERATION (QUICK SETUPS 11 AND 12)

The Bell 208 Quick Setup, available on the Modem only, configures the

modem for 2-wire dial synchronous operation compatible with Bell standard

208B. The data rate is fixed at 4800 bps, and the data format is set to

synchronous. Both connected modems must be set for 208B operation.

For additional information on Bell 208 operation, see Chapter 4.

Beginning with the section titled Answering a Call Automatically,

all information in Section 2.4.3 also applies to Bell 208 operation.

Three options are intended for Bell 208 (and V.33) operation exclusively.

These options are listed in Section 3.3.8.

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2.0 Quick Start

2.4.7 4-WIRE LEASED LINE V.29 MODE (QUICK SETUP 13)

The 4-Wire Leased Line V.29 Mode configures the modem for V.29

operation, for compatibility with V.29 modems. Keep these guidelines

in mind when using this mode:

• The modem must be configured for use with a 4-wire line.

• Operation is restricted to data rates of 4800, 7200, and 9600 bps.

• Lines can be conditioned or unconditioned.

After you select this Quick Setup mode, the modem will send a training

sequence and wait for a training response from the remote modem. The

modem will repeat the training sequence every 1.2 seconds until the remote

modem responds.

When the local modem has established a connection with the remote unit,

the TIE/EIA status screen will appear.

NOTE

For point-to-point 4-wire leased-line V.29 operation, the Auto-Retrain

option should be enabled on both modems. (Auto-Retrain is enabled by

default if you select the 4-wire Leased Line V.29 Quick Setup.) If the

Auto-Retrain option is disabled, the modem will not transmit a training

sequence and will instead train on the data stream from the remote

modem. Disabling Auto-Retrain in 4-wire leased line V.29 mode is

recommended for test purposes only. If Auto-Retrain is disabled, it

should be disabled on both modems.

V.34/V.32 Dial Backup

NOTE

Dial backup can only be used in point-to-point applications.

To prevent service interruption in the event of poor leased line conditions,

the modem can be configured for V.29 leased line operation with V.34/V.32

dial backup. This means the modem will use dial lines to automatically restore

operation when conditions on the leased lines deteriorate. (Use V.34 or V.32

modulation for dial backup.) To set up the Modem for V.29 leased line

operation with dial backup, follow these steps:

1) Select the 4-wire leased line V.29 (4-WLL V.29) Quick Setup on both the

local and remote modem.

2) One modem must be set to originate mode and the other to answer mode.

To make this selection, use the ANS/ORG DEFAULT screen on the front

panel LCD.

3) Configure the modems for leased line auto-recovery.

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Modem 34336

2.4.8 V.29 FAST MASTER AND SLAVE MODES (QUICK SETUPS 14 AND 15)

In multidrop operation, the master modem transmits to all of the slave

(remote) modems. When the DTE at a slave site recognizes its own address in

the polling protocol, it raises RTS to the slave transmitter. The slave responds

by transmitting a special training sequence, then raising CTS and transmitting

the data from the DTE. When the DTE has completed transmission, it lowers

RTS and the modem will drop carrier to let the next modem on the poll list

use the channel.

The V.29 Fast Master and Fast Slave modes support data rates of 4800, 7200,

and 9600 bps. The leased lines can be conditioned or unconditioned. The

master modem must be set to originate mode, and the slave modem must be

set to answer the mode. (The Answer/Originate option is automatically set to

these settings when the V.29 Fast Master and Fast Slave Quick Setups are

used.)

Slave-to-Master (Inbound) Transmission

When the remote modems come on-line, they automatically synchronize to

the incoming carrier and train on the data stream from the master modem.

Slave-to-master transmission is always switched carrier operation under

control of the RTS signal from the DTE. An anti-streaming timer built into

the modem will (if enabled) halt transmission if the DTE holds RTS on for

more than 30 seconds. The assumption is that if RTS is held on for more

than 30 seconds, there is a fault in the DTE.

If you access the TIA/EIA status screen on the LCD display when a slave

modem is transmitting to the master modem, the status screen will typically

look like this:

TR MR RS CS TD

9600

CD RD

Typically TD, CD, and RD will flash on the master modem, and RS, CS, TD,

and RD will flash on the slave modems.

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2.0 Quick Start

2.5 Problem Solving

If you encounter difficulties in setting up or using the modem, try the

remedies described below. If you suspect a system malfunction, follow the

diagnostic procedures described in Chapter 7. If you cannot resolve the

problem, call your supplier.

1. ALL MODES

Make sure all cables are properly connected to the back of the modem.

2. ALL DIAL MODES (HAYES, V.25 BIS, DUMB, BELL 208, AND V.32/208)

DTR (Data Terminal Ready) must be ON if you want to use the modem’s

autodial or auto-answer features. (If DTR is ON, the TR indicator is present

on the EIA status screen.)

3. ALL ASYNCHRONOUS MODES

The modem’s default DTE speed is 38.4 Kbps in asynchronous mode. If the

local DTE does not support this speed, change the modem’s DTE Speed

option setting. In Hayes mode, the default DTE speed is automatically

overridden when the Modem is autobauded (the Hayes mode AT attention

code is sent to the Modem).

4. HAYES MODE

In Hayes mode with default settings in effect, the Modem transmits result

codes (messages) to the DTE. In some instances, this may cause undesirable

interaction with the attached DTE. If such interaction occurs, use the AT Q2

command to suppress result codes for incoming calls.

5. ALL LEASED-LINE MODES (2-WIRE, 4-WIRE, AND V.33)

DTR (Data Terminal Ready) must be ON for the units to train on the leased

line. (If DTR is ON, the TR indicator is present on the EIA status screen.)

Four types of compromise equalization are available to compensate for

distortion. If the signal quality appears to be inadequate (see Quality Screen

in Section 7.6.2), or if the modems are frequently retraining, try changing

the equalization option. See Compromise Equalizers in Section 3.3.6.

6. LEASED-LINE (EXCLUDING V.33 OPERATION)

Make sure one modem is set to originate mode and that the other is set to

answer mode. (If the correct Quick Setup is selected, and not incorrectly

modified, the answer/originate status should be correct.)

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Modem 34336

NOTE

This page is intentionally left blank.

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3.0 Modem Setup Options

3.1 Methods For Selecting Options

The Modem allows you to easily select options for tailoring the modem’s

operation to suit a particular application. You can be select options in the

following ways:

• Quick Setup — the easiest way to set up the Modem. Quick Setup

(explained in Chapter 2) automatically sets all options according

to a preset configuration.

• Front-panel selection — the easiest and most commonly used method for

selecting individual options. You can select an overall configuration via

Quick Setup, and then change selected options from the front panel to

suit your application. To make changes, access individual option screens

on the front panel LCD. Make selections using the control pushbuttons.

• Summary Setup — the fastest way to selectively change options. All

options are accessed using a few of the LCD screens. These screens show

numerical codes with very little explanation. Therefore, Summary Setup

is recommended for experienced users only. Summary Setup is explained

in Appendix C.

TRANSMITTER

RECEIVER

PATTERN

GENERATOR

PATTERN

DETECTOR

Figure 3-1. LCD Pushbuttons.

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Modem 34336

3.2 Selecting Options from the Front-Panel

3.2.1 PUSHBUTTONS AND THE LCD

Options are selected from the front panel by pressing the front panel

pushbuttons (Figure 3-1). The possible choices for each option are shown

on the liquid crystal display (LCD) and on the flow chart at the back of this

manual.

1. Arrow Pushbuttons. Use the left arrow and right arrow pushbuttons to

display additional or previous pages (screens) of a menu. The right arrow

pushbutton displays an additional menu page (if there is one); the left arrow

pushbutton displays the previous page of a menu. With respect to how the

LCD flow chart is set up, the arrow pushbuttons move you either right or

left within the chart.

If the menu has more than one screen, each screen is numbered. This

number appears in the upper right corner of the LCD display. If there is no

page number, the menu has only one screen. Additional pages of a menu

show additional option selections. In the example below, the screen number

(or page number) is 2.

MAIN MENU <2>

SETUP TEST RMT

2. Numbered Pushbuttons. Pushbuttons 1, 2, and 3 correspond to segments

1, 2, and 3 of the LCD screen. These segments (left, middle and right

positions of the LCD screen) are numbered on the modem’s front panel.

With respect to how the LCD flow chart is organized, pushbuttons 1, 2,

and 3 either take you to a lower level or allow you to select an option

when there is no route to a lower level.

3. ENT Pushbutton. To exit from a displayed screen, press the ENT

pushbutton. With respect to how the LCD flow chart is set up, pushing

ENT moves you upward through the chart (toward the MAIN MENU).

Pressing ENT repeatedly will return you to screen 1 of the MAIN MENU.

Pressing ENT repeatedly after arriving at the MAIN MENU screen 1 causes

the LCD to alternate between the EIA status screen and the MAIN MENU.

In the case of most tests, ENT cannot be used to exit the test screen once

the test is activated. To exit a test, first press ENT, and then select OFF

to end the test.

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3.0 Modem Setup Options

NOTE

If you have selected a Quick Setup or have changed certain options

settings, pressing the ENT pushbutton to exit the SETUP menu will

cause the modem to reset.

3.2.2 HOW

SELECT OPTIONS

Options are configured from the SETUP menu.

To access the SETUP menu, press the right-arrow pushbutton at

page 1 of the MAIN MENU. This will take you to page 2 of the MAIN MENU.

Press push button 1 to select SETUP.

SETUP

<1>

TYPE LINE SPEED

Front panel

LCD

The SETUP menu has six screens. Use the arrow pushbuttons until the

option you wish to configure is displayed on the bottom line of the LCD

window. Select the option you wish to configure by pressing the pushbutton

that corresponds to the number on the front panel.

When you select an option, the option flashes on the LCD. The option will

not take effect until you leave the SETUP menu. Simply accessing an option

screen does not change the option, so not hesitate to move through the

various LCD screens in the SETUP menu.

Note the following points:

• Selected options do not become active until you leave the SETUP menu.

• Changing some options causes the modem to automatically reset.

• The options you select are automatically saved by the Modem when

you leave the SETUP menu.

1. DEC/INC (Decrease/Increase) Screens. Several option screens show

the abbreviations DEC and INC on the bottom line of the LCD display. The

abbreviations mean the numerical value shown on the top line (e.g., a stored

phone number) can be changed. Selecting DEC (pushbutton 1) decreases

the value; selecting INC (pushbutton 3) increases it.

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Modem 34336

2. Option-Selection Example. The following example illustrates option

selection. As you follow the steps below, refer to the LCD flow chart (SETUP

OPTIONS side) at the back of this manual. When you are finished, you can

easily restore default settings for the type of application you are using by

selecting the appropriate Quick Setup (see Section 2.3, Quick Setup).

The example shows how to change the volume of the modem’s speaker from

LOW or HIGH (the default setting) to MEDIUM. To make this adjustment,

locate the SPEAKER VOLUME screen on the LCD. Access MAIN MENU

screen 2, then SETUP screen 4. Finally, access MODEM SETUPS screen 5.

The steps are explained in detail below.

After powering on the modem, press ENT to get the first screen of the MAIN

MENU. Press the right arrow pushbutton to go to screen 2 of the MAIN

MENU, shown below.

MAIN MENU <2>

SETUP TEST RMT

SETUP

<1>

Press pushbutton 1 to access the first

page of the SETUP menu, shown right.

TYPE LINE SPEED

SETUP

<4>

Press the right arrow pushbutton

three times to display SETUP screen 4,

shown left.

TEST EIA MODEM

MODEM SETUPS <1>

Press pushbutton 3 to select MODEM

(for MODEM SETUPS). The first

MODEM SETUPS screen is shown right.

CDLVL

TXLVL

MODEM SETUPS <5>

Press the right arrow pushbutton four

times to reach MODEM SETUPS

screen 5, shown left.

FP SPK SPKVOL

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3.0 Modem Setup Options

Press pushbutton 3 to select SPKVOL

(speaker volume). The SPEAKER

VOLUME screen is shown right.

SPEAKER

VOLUME

LOW MEDIUM HIGH

The currently selected setting flashes. Press pushbutton 2 to switch the

volume setting to MEDIUM. MEDIUM begins to flash, indicating the new

selected setting (although the new selection does not become active until

you exit the SETUP menu). To return to the first page of the MAIN MENU,

press the ENT button several times.

3. Returning to the EIA Status Screen. Once your selection is complete,

return to the EIA status screen. Press the ENT pushbutton several times—

the exact amount depends on which screen you are exiting from. (If the

modem is in a test mode, press ENT and select OFF to end the test.)

4. Automatic Configuration Save Feature. When you exit the SETUP menu,

the Modem automatically saves its current configuration (i.e., option setups,

including any changes you made) to its internal memory. The saved

configuration remains in effect until it is changed (even if a loss of power

occurs).

5. How to Return to Default Settings. The factory default settings are

different for each of the Quick Setup configurations available to the modem.

To return to the factory default settings for any of these configurations, go to

the QUICK SETUP menu and select the desired configuration.

The 2-Wire Dial (Hayes) Quick Setup does not recall the factory-default

settings, it recalls the stored user profile 0 or 1, depending on which is

designated as the default (see &Y command in 5.0, Hayes Emulation Mode).

To entirely reconfigure the modem to the state it was in when shipped from

the factory, hold in the right arrow pushbutton as you power up the modem

until the words FACTORY DEFAULT appear on the LCD.

3.3 Options

The rest of this chapter describes the options available from the Modem’s

front panel. The options are presented in the same order in which they

appear in the LCD flow chart at the back of this manual.

The line below each option heading indicates the applicability of the option.

A Quick Setup mode is listed only if the option is effective in that mode and

if it can be of practical use in that mode.

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Modem 34336

The default settings for each option are listed in Appendix B.

The Quick Setup options (one for each operating mode) affect the entire

modem configuration. See Chapter 2.

The Line Type options are available for all modes:

• 2-WIRE DIAL — for dialup applications.

• 2W-LL — for leased-line applications using 2-wire lines.

• 4W-LL — for leased-line applications using 4-wire lines.

The Speed Limit option (available for all modes) allows you to set a minimum

and/or maximum data rate. The Modem automatically operates at the

highest possible data rate within the limits selected, as indicated in Table 3-1.

Only the minimum rate selection applies to Hayes mode operation.

EIA-23 is available for setting the maximum rate only. If EIA-23 is selected,

the rate is set at either 9600 or 4800 bps, depending on the condition of

pin 23 on the EIA interface:

• Pin 23 high (greater than or equal to +3 volts) = 9600 bps.

• Pin 23 low (less than or equal to -3 volts) = 4800 bps.

Use the Speed Matching option if you don’t want speed conversion. You can

set the DTE interface rate to follow the rate at which the modem connected

(i.e., DTE=DCE).

NOTE

Speed matching is only effective for dial applications and will

only function if V.42 error correction and/or buffer mode is enabled.

To select speed matching, refer to Appendix C. Follow the instructions given

there to change the value identified in the MISCELLANEOUS OPTIONS

diagram as the DTE=DCE speed parameter from 0 (the factory setting) to 1.

The Speed Limit Type screen is only present on the Modem . The V.32

master handshake normally used by the Modem is incompatible with the

CCITT V.33 and Bell 208 handshakes. However, the Modem can be

configured for either V.33 or Bell 208 compatibility.

V.33 or Bell 208 speed limits can be set independently of other options via

the Speed Limit Type screen. However, to ensure proper operation, it is

recommended that you use the V.33 or 208 Quick Setup configuration,

as explained in Chapter 2.

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3.0 Modem Setup Options

Table 3-1. Effect of Speed Limit Settings on Data Rate

MAX RATE

SETTING, bps

DIALER

OPTION

RESULTANT DATA RATE, bps

LEASED LINE MODES

14,400¹

12,000¹

14,400¹

12,000¹

9600

300 to 4800

EIA-CTRL

4800

9600 or 4800²

DIAL MODES—ANSWERING

300 to 14,400¹

EIA-CTRL

Negotiated between minimum and

maximum setting

9600 or 4800²

DIAL MODES—ORIGINATING

300 to 14,400¹

OFF

Negotiated between minimum and

maximum setting

EIA-CTRL

OFF

HAYES³

9600 or 4800²

Negotiated between autobaud

speed and 300 bps³

xx Does not matter—condition does not affect resultant data rate.

14,400 and 12,000 bps rates are for the Modem only.

9600 bps if EIA pin 23 is high, 4800 bps if pin 23 is low.

If SYNC AFTER DIAL is enabled (using the &Q1 command), the

rate is negotiated between the autobaud speed and 1200 bps.

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Modem 34336

• V.32. The Modem normally uses the V.32 handshake. (The Modem also

uses this handshake for V.32/14,400 bps operation.)

• V.33. V.33 operation is available on the Modem for 4-wire leased line

synchronous operation only. The available data rates are 14,400 and

12,000 bps. Either of these rates may be set as the maximum or minimum

by using the Speed Limit MAXIMUM RATE and MINIMUM RATE

screens. Both connected modems must be set for V.33 leased-line

operation.

• V.34. V.34 extended (33.6 kps) mode of operation is in compliance

with proposed TR-30.1 implementation of two new data rates (31.2kps

and 33.6kps) which are compatible with V.34 recommendation.

Interoperability with modems is ensured, provided they comply

with the TR30.1 proposal.

• 208. This selection (on the Modem only) provides both Bell 208A

compatibility for 2-wire or 4-wire leased line operation and Bell 208B

compatibility for 2-wire dial operation. Operation is full duplex in 4-wire

leased line mode only. In Bell 208B mode, synchronous V.25 bis

autodialing is available, but Hayes operation is not. In Dumb mode, calls

may be originated from the front panel. The data rate is fixed at 4800 bps

for 208A/B operation, and the data format is synchronous only. Both

connected modems must be set for 208A/B operation. For 2-wire

applications, the carrier option must be set for switched carrier operation

(SWITCH) via the CARRIER screen, and CTS must be set to follow RTS

(CTS to EIA option).

Three options intended only for 208A/B and V.33 operation are accessible

through MODEM SETUPS screen 7. These options allow you to select

constant or switched carrier, set CTS to follow RTS or set CTS to be always on,

or specify an RTS-CTS delay time. For further information, see the CARRIER,

CTS, and RTS-CTS DELAY headings later in this chapter.

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3.0 Modem Setup Options

3.3.1 V.42 ERROR CORRECTION OPTIONS

The Modem supports both CCITT V.42 error correction and Microcom

Networking Protocol (MNP ) error correction (classes 1 through 5).

V.42 and MNP provide end-to-end error correction through an automatic

repeat-transmission request algorithm. Both types of error correction

enable the Modem to detect data transmission errors and automatically

request retransmission of adversely affected data until it is received correctly.

Either error-correction standard (V.42 or MNP) may be enabled for dial

or leased-line operation. However, error correction can function only if

all of the following conditions are present:

• The modem that the Modem is communicating with must be equipped

with the same type of error correction (V.42/V.42 bis or MNP).

• The same type of error correction (V.42/V.42 bis or MNP) must be

enabled at both ends of the communication link.

• Both communicating modems must be configured for asynchronous

data format.

• The connected systems must support data flow control (have buffering

capabilities).

The V.42 and MNP error-correction options (listed and described below)

are effective only when all of the conditions listed above are present.

Error correction options cannot be changed when the modem is on-line.

For valid test results, disable error correction before running diagnostic tests.

User-selectable options allow you to configure the Modem for V.42 (LAPM)

error correction only, MNP error correction only, or V.42 error correction

with MNP as the fallback error correction protocol. Data compression may

also be enabled by selecting either V.42 bis or MNP class 5 error correction.

Other error-correction options are also available.

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Modem 34336

The available error correction options are listed below:

• V.42 Mode

• DTE Speed

• MNP Class (class limit)

• Break Handling

• DTE-DCE and DCE-DTE Flow

Control options

• V.42 Selection

• Flyback Buffer

• Buffer Mode/Speed Conversion

• Pass-Through Flow Control

All of the above options affect the type of error correction selected via the

V42 SELECTION screen (discussed below), except that the MNP Class and

Flyback Buffer options are applicable only to MNP operation.

The error-correction options can be selected in any order, but the following

sequence is suggested:

1. Select the type of error correction desired from the V42 SELECTION screen.

2. Make a selection from the V.42 Mode screen.

3. Select other error-correction options as appropriate for your application.

The V.42 Mode is available for Hayes, V.25 bis, Dumb, and Leased-Line

modes (except V.33).

The V.42 Mode settings described below apply to the type of error correction

selected with the V42 Selection screen. For example, if LAPM ONLY is

selected as the error correction protocol, and MANDATORY is selected

from the V42 Mode screen, V.42 or V.42 bis error correction is activated.

If the error correction cannot be activated, the Modem will hang up.

• OFF — Error correction will be disabled.

• MANDATORY — Error correction will be activated. If the modem cannot

establish a connection using the type of error correction selected via the

V.42 Selection option, it will hang up.

• AUTO — The Modem will fall back to buffer or non-buffer mode if

conditions do not allow it to establish a connection using the type

of error correction selected via the V42 SELECTION screen.

The MNP Class (Limit) is available for Hayes, V.25 bis, Dumb, Leased Line

modes (except V.33). This option is effective only when MNP error correction

is active. It limits MNP operation to the selected MNP class or lower (MNP

classes 1-5 are available). In general, the higher MNP classes provide the most

throughput efficiency. Class 5, the default, can provide as much as 2-to-1 data

compression over the transmission link.

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3.0 Modem Setup Options

The following two options are available through the V42 SELECTION screen:

The Protocol option is available for Hayes, V.25 bis, Dumb, and Leased-Line

modes (except V.33).

• LAPM/MNP — The Modem attempts to establish a connection using

the V.42 link access protocol (LAPM/MNP). This is the primary error

correction protocol under the CCITT V.42 standard. If such a connection

cannot be established (because the other modem does not support LAPM

or is not configured for LAPM), the Modem attempts to establish a

connection using MNP Class 5 as the fallback error correction protocol.

NOTE

When operating in LAPM mode, the Modem uses V.42 error correction

unless V.42 bis is enabled via the V.42 bis option. (V.42 and V.42 bis

error-correction both use LAPM.)

• LAPM ONLY — The modem only attempts to establish an LAPM

connection (will use only V.42 or V.42 bis error correction).

• MNP ONLY — The modem will only attempt to establish an MNP connection.

NOTE

If a connection cannot be established using the selected protocol (LAPM/

MNP, LAPM ONLY or MNP ONLY), the action the Modem takes depends

on the V.42 mode setting.

V.42 bis Operation is available for Hayes, V.25 bis, Dumb, and Leased-Line

modes (except V.33). V.42 bis operation provides error correction with

data compression. Like V.42 error correction, V.42 bis uses the link access

protocol (LAPM). V.42 bis operation may be enabled or disabled.

The Break Handling option is available for Hayes, V.25 bis (Async only),

Dumb, Leased line modes (except V.33). When error correction is active,

a break signal is relayed with an attention packet. The break-handling

option determines how the attention packet is sent.

• NONE — No attention packet is sent.

• DESTRUCTIVE/EXPEDITED (DESTR/EXP) — All data in the buffer

is deleted; the attention packet is then passed through the channel.

• NON-DESTRUCTIVE/ EXPEDITED (NDT/EXP) —The attention packet

is passed through immediately, but data in the buffer is not deleted.

• NON-DESTRUCTIVE/NON-EXPEDITED (NDT/NEXP) — The

attention packet is passed through the channel in sequence, and any

data is buffered; this preserves the sequence of data and breaks received.

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Modem 34336

The Buffer Mode/Speed Conversion option Hayes, V.25 bis, Dumb, Leased

line modes (except V.33). It enables or disables speed conversion (for

asynchronous operation only) between the DTE and modem when error

correction is not used.

• ENABLE — When error correction is not enabled, the V.42 circuit

functions as a buffer between the DTE and the modem and provides

transmission speed conversion.

• DISABLE — Speed conversion is not allowed.

The DTE Speed option is available for Hayes, V.25 bis, Dumb, Leased-Line

modes (except V.33). It controls the DTE speed; however, it is effective only

when the modem is operating in V.42 mode, MNP mode, or buffer mode.

The DTE speed can be set for 115,200, 57,600, 38,400, 19,200, 9600, 4800,

2400, 1200, 600, 300, or 110 bps. The default "DTE speed" is 38,400 bps.

DTE speed refers to the speed of data transfer between the DTE and the local

modem. It is not necessarily the same as the data transmission speed between

the connected modems. If flow control is disabled, the DTE speed must be

equal to or less than the modem speed, and the local and remote DTE speeds

must be equal.

For Hayes mode operation, the DTE Speed option sets the default DTE speed

that will be effective after powerup or after a full modem reset. However, the

default DTE speed is automatically overridden when the Modem is

autobauded (when an AT attention code is sent to the Modem).

The Flow Control options control the data flow according to the availability

of memory space in the V.42 buffer. Flow control can be set independently

for the modem to the terminal and for the terminal to the modem. The

flow-control options include DTE-DCE, DCE-DTE and Pass-Through Flow

Control, and Flyback Buffer.

NOTE

When flow control is disabled, the DTE data rate must be equal to or less

than the modem data rate, and the local and remote DTE data rates must

be equal. (This precludes the need for flow control, which some

computers and terminals cannot handle, and avoids buffer overflow.)

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3.0 Modem Setup Options

The DTE-DCE Flow Control options are available for Hayes, V.25 bis, Dumb,

and Leased-Line modes (except V.33).

• NONE — No flow control is used.

• RTS ON/OFF — The Request to Send signal controls

data flow from the modem to the terminal.

• DC1/DC2 — Inserts control characters (CONTROL-R and CONTROL-Q)

in the data stream stop and start the flow of data from a device.

• DC1/DC3 (X-ON/X-OFF) — The most common method of flow control.

It inserts control characters into the data stream: CONTROL-S stops the

flow of data, and a CONTROL-Q restarts it.

NOTE

When using the modem for binary file transfer, in-band flow control (flow

control using control characters) must be disabled. In this case, use

hardware flow control or, as an alternative, lower the DTE speed to

lessen the possibility of overflow.

The DCE-DTE Flow Control options are available for Hayes, V.25 bis, Dumb,

and Leased-Line modes (except V.33). All information given above under

DTE-DCE Flow Control options also applies to DCE-DTE (modem to

terminal) flow control options, except that the CTS, Clear to Send,

signal is used to control DTE-DCE data flow instead of RTS.

Flyback Buffer options are available Hayes, V.25 bis, Dumb, Leased line

modes (except V.33). The Flyback Buffer option is effective only when MNP

error correction is active. Flyback buffering is used for specific applications

such as printers, teletypes, etc.

• ENABLE — If MNP is buffering data, a five-character delay is inserted

after the following characters are sent to the terminal: HT (09), LF (0A),

VT (0B), FF (0C), and CR (0D).

• DISABLE — Flyback buffering will not occur.

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Modem 34336

The Pass-Through Flow Control options are available for Hayes, V.25 bis, Dumb,

and Leased-Line modes (except V.33). Pass-Through Flow Control affects DTE-

DCE flow control only. This option determines whether flow control characters

are passed through the communication channel (but only if control characters

are used for flow control).

• ENABLE — Flow-control characters are passed to the remote end

of the communication connection after the modem acts upon them.

• DISABLE — Flow-control characters are not passed.

The Address option is available for all modes. The address screen allows you

to set the address of the modem at your location. An address may be useful

if the Modem will be used in a rack enclosure or in a network environment.

The available address numbers are 000,000 through 999,999. On the Address

screen, the three digits to the right of the comma are the unit address

number. The three digits to the left are the group address number. To

change the address, use the right and left arrow pushbuttons to go to the digit

you want to change. Then use pushbutton 1 to decrease (DEC) a number and

pushbutton 3 to increase (INC) it. The default address is 999,999.

3.3.2 DIALER MODE

Several Dialer Mode options can be selected from the DIALER and DIAL

V25bis screens.

The Dialer Options are available for all modes.

• OFF — The autodialer is off, meaning the modem operates in Dumb

mode only. Calls must be made using the front panel AUTO-DIAL

function or they must be manually originated.

• HAYES — The autodialer automatically dials previously stored phone

numbers, and the modem responds to Hayes commands.

• DTR — This selection enables DTR dialing, an option that allows you to

set up the Modem to automatically dial a stored number even when the

autodialer is not enabled. (For further information, see Section 4.5).

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3.0 Modem Setup Options

The V.25 bis Dialer Modes are available for V.25 bis mode.

Any of the selections from the DIAL V25bis screen will enable the V.25 bis

autodialer. For detailed information on the V.25 bis autodialer, see Chapter 6.

The three selections on the DIAL V25bis screen allow you to select a data

protocol that is appropriate for the DTE the Modem is connected to:

• ASYNCHRONOUS (Asyn)

• SYNCHRONOUS, CHARACTER ORIENTED (Syn_c)

• SYNCHRONOUS, BIT ORIENTED (Syn_b)

NOTE

DTR dialing for V.25 bis mode cannot be enabled through the DIALER

screen. To select DTR dialing for V.25 bis mode, you must use the

Summary Setup feature, as explained in Chapter 6.

The Auto-Answer option is available for Hayes, V.25 bis, and Dumb modes. It

determines whether or not a call is automatically answered when the phone

rings. Setting the Auto-Answer option to ENABLE resets Hayes mode register

S0 to 1 (meaning that calls are answered on the first ring).

3.3.3 DATA FORMAT OPTIONS

The Data Format (Sync or Async) option is available for V.25 bis, Dumb, and

Leased-Line modes. The data format setting for the local modem and for the

remote modem must be the same.

• ASYNCHRONOUS — Data is transmitted and received in the character

asynchronous format. The character length (next option) must be the

same for both communicating modems.

• SYNCHRONOUS — If this option is selected, data must be transmitted

and received in the synchronous format. The appropriate transmitter

clocking option must be selected. The synchronous data format is not

available for data rates of 300, 19,200, or 38,400 bps.

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Modem 34336

The Character Length option is available for all modes (asynchronous

operation only). It selects a character length of 8, 9, 10, or 11 bits for

character asynchronous operation. The same character length must be

selected for both the local and the remote modems. Use pushbuttons

1 and 3 to select the desired character length.

• 8 BITS: 1 start bit, 6 data bits and 1 or more stop bits.

• 9 BITS: 1 start bit, 7 data bits and 1 or more stop bits.

• 10 BITS: 1 start bit, 8 data bits, including parity, and 1 or more stop bits.

• 11 BITS: 1 start bit, 9 data bits, including parity, and 1 or more stop bits.

In Hayes mode, character length is set automatically under most conditions.

The Parity option is available for all modes. Parity selections are effective

only if error correction or buffer mode has been enabled or if the Modem

is in 2-Wire Dial (Hayes) mode. For most applications, parity should be set

to NONE.

The following parity options are available: NONE (no parity), ODD, EVEN,

MARK (parity is always 1) and SPACE (parity is always 0). All parity settings

except NONE automatically enable parity conversion (except in Hayes

mode), meaning that the parity of received data is converted to match the

selected parity option.

In Hayes mode, parity is set automatically under most conditions.

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3.0 Modem Setup Options

3.3.4 DISCONNECT OPTIONS

When the modem is operating in V.25 bis or Dumb mode, it is necessary to

disconnect the modem from the telephone circuit once communications are

completed. The most common form of disconnection is by dropping the Data

Terminal Ready (DTR) signal from the DTE. However, some applications may

require one of the five available automatic disconnect methods listed below.

For all five disconnect options, "disabled" means the modem will not

disconnect in the presence of the conditions specified below.

The RX (Receive) Space Disconnect option is available for Hayes, V.25 bis,

and Dumb modes. If it is enabled, a 1.6-second continuous space will cause

the modem to disconnect.

NOTE

For Hayes mode operation, both the RX Space Disconnect and TX Space

Disconnect options must be either enabled or disabled.

The TX (Transmit) Space Disconnect option is available for Hayes, V.25 bis,

Dumb modes. When TX Space Disconnect is enabled, the Modem transmits

4 seconds of space prior to disconnecting from the line. This ensures a clean

disconnect if RX space disconnect is enabled on the remote modem.

NOTE

For Hayes mode operation, both the TX Space Disconnect and RX Space

Disconnect options must be either enabled or disabled.

The Character Disconnect option is available for V.25 bis, and Dumb modes.

If it is enabled, a 400-ms loss of carrier signal causes the line to be

disconnected. (To set this option for Hayes mode, use S register S10 --

see Section 5.3.)

The Line Current Disconnect option is available for V.25 bis, Dumb modes.

If enabled, a 400-ms loss of current causes the line to be disconnected.

(To set this option for Hayes mode, use S register S10 -- see Section 5.3.).)

The RTS Disconnect option is available for Hayes, V.25 bis, and Dumb modes.

When RTS Disconnect is enabled, if RTS is off for a selected period

of time (20 to 140 seconds, user selectable), the line is disconnected.

Use pushbuttons 1 and 3 to set the RTS-OFF period required for a

disconnect.

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Modem 34336

3.3.5 TEST OPTIONS

The Test Options affect certain tests (as explained below) but do not activate

tests.

The DSR During Analog Loopback is available for all modes. When ON

is selected, the Data Set Ready signal is forced on when the modem is in

the analog loopback test mode. In general, this option should be left ON

(the default selection).

The Remote Test option is available for all modes. The Remote Test option

allows you to prevent tests from being initiated on the local Modem from a

remote modem. If DISABLE is selected from the Remote Test screen, the

local Modem ignores test initiation signals from a remote modem. If ENABLE

is selected, tests can be initiated from a remote modem.

Note that there are two REMOTE TEST screens. One is for the option just

described; the other is used for selecting either the remote digital loopback

tests or remote front panel control. The Remote Test option screen (for

preventing or allowing remote testing) looks like the one shown below.

REMOTE TEST

ENABLE DISABLE

3.3.6 EIA OPTIONS

The seven options described below allow control over specific EIA interface

signals.

The CTS to EIA options are available for all modes. Regardless of the setting

selected for this option, Clear to Send (CTS) is off during flow control (which

occurs if error correction and flow control or buffer mode are enabled).

• NORMAL — The Clear to Send signal is on while the modem is on-line.

• RTS — The CTS signal immediately follows the RTS signal with no delay.

• TRUE — The CTS signal follows DTR.

CTS can also be set to be ON at all times regardless of DTR by using the

Summary Setup feature. However, if CTS on/off is selected from DCE-DTE

screen 1, V.42 flow control, while active, overrides the CTS ON selection.

To set CTS ON, refer to Appendix C. Note that if you set CTS to ON using

Summary Setup and then make a selection from the CTS to EIA screen,

that selection cancels the Summary Setup CTS ON selection.

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3.0 Modem Setup Options

NOTE

The Modem also supports a CTS option intended only for V.33

and Bell 208A/B operation, described later in this chapter.

The CD to EIA option is available for Hayes, V.25 bis, and Dumb modes.

• NORMAL — Carrier Detect (CD) is on while the modem is on-line.

• TRUE — CD follows DTR supplied from the DTE.

• TOGGLE — CD turns on whenever DTR is present and then toggles

off for 500 ms upon disconnect, allowing the attached DTE to

recognize that the call is ended and the connection is dropped.

The DSR to EIA option is available for Hayes, V.25 bis, and Dumb modes.

• NORMAL — Data Set Ready (DSR) is on while the modem is on-line.

• TRUE — DSR follows DTR supplied from the DTE.

• CROSSOVER (XOVER) — DSR is ON without DTR and toggles for

500 ms upon local or remote disconnect.

The DTR from EIA is available for all modes. It allows you to force the Data

Terminal Ready (DTR) signal on (TRUE), which may be needed if your

computer or communication software does not supply a DTR signal.

• NORMAL — DTR is supplied by the DTE.

• TRUE — The DTR signal is internally forced ON regardless of the DTR

status at the interface.

The DTE Control Of ALB (ALB- DTE Ctrl’ed) option is available for all

modes. Analog loopback (ALB) testing can be initiated from the DTE via

pin 18. Positive voltage activates the test, whereas negative voltage results in

normal operation. Disabling this option keeps the modem from responding

to pin 18.

The DTE Control Of RDL (RDL- DTE Ctrl’ed) option is available for all

modes. Remote digital loopback (RDL) can be initiated from the DTE via

pin 21. Positive voltage activates the test, whereas negative voltage results in

normal operation. Disabling this option keeps the modem from responding

to pin 21.

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Modem 34336

The Test Mode (TM to EIA) option is available for all modes. It controls

pin 25, the test mode (TM) indicator, on the RS-232 interface connector.

• NORMAL — TM output is high (active) only during test modes.

• TRUE — TM output is high all of the time.

3.3.7 MODEM SETUPS

The options listed below, through RTS-CTS DELAY, are available through

the MODEM SETUPS screens.

The Carrier Detect option is available for all modes. It selects the carrier

detect level. To make a selection, first select either LEASED or DIAL from the

CARRIER DET. LVL screen, depending on your application. The appropriate

carrier detect level screen is displayed.

• For leased-line use — the carrier detect level can be set for 43, 33 or 26

dBm. The default setting is 26 dBm.

• For dial-line use — the carrier detect level can be set for 51, 41, or 34

dBm. The default setting is 51 dBm.

The Transmit Level option is available for all modes. It controls the modem’s

transmission level. To make a selection, first select either LEASED or DIAL

from the TRANSMIT LEVEL screen.

• For leased lines — the transmission level can be set between 0 and -15

dBm, in 1-dBm steps. The standard setting is 0 dBm. (Use pushbuttons 1

and 3 to select the desired transmission level.)

• For dialup applications — the transmission level for dial lines can be set as

either programmable, if you are using RJ-45S connectors, or permissive,

fixed at -10 dBm +/-1 dBm, which is the most common setting.

The Signal Quality option is available for all modes. It sets the threshold for

the ER (error) indication during normal operation. You can choose either

"10 3", one error in 1000 bits, or "10 5", one error in 100,000 bits. Signal

quality (along with carrier detect) also controls the threshold the modem uses

as a criterion for entering the Leased Line Auto-Recovery mode.

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3.0 Modem Setup Options

The Compromise Equalizers option is available for all modes.

NOTE

The compromise equalizers affect only V.32 operation (4800 to 14,400

bps, asynchronous/synchronous, full duplex).

For most applications, the automatic adaptive equalizer setting provides all

the equalization necessary to compensate for line impairments, meaning that

equalizer adjustments are generally not necessary. However, in the event that

equalizer adjustment is needed, any of four types of compromise equalization

can be selected: Type I (T-I on the LCD), Type II (T-II), Type III (T-III) and

Type IV (T-IV). The equalizer can also be turned OFF.

Where line conditions are atypical, it may be necessary to adjust the equalizers

to optimize the signal quality. If adjustment is necessary, refer to the quality

screen for guidance; this screen shows a relative indication of the signal

quality, in both numeric and graphic form.

The Trellis Code option is available for all modes. Trellis coding provides

performance advantages for all modulation patterns. The modem’s CCITT

compliant trellis coder is normally enabled at speeds of 9600 bps and above,

but may be negotiated off by a modem that is not equipped with a trellis

coder. The trellis code option allows you to enable or disable the trellis coder.

The Transmitter Clocking option is available for all modes. It selects one of

three possible sources for the transmitter timing signal:

• INTERNAL — The timing of the modem and data terminal transmitting

circuits is provided by an internal clock within the modem.

• RECEIVED (RX-CLK) — The timing of the received data is used to

control the timing of the data transmitted. This timing mode is used if the

modem’s transmit timing must be controlled by a remote source.

• EXTERNAL — The timing of the modem and data terminal transmitting

circuits is provided by an external clock within the data terminal and is

provided to the modem via the DTE connector pin 24. This mode of

clocking is used if the DTE must be in control of the modem’s transmit

timing.

The T1 Timer option is available for Hayes, V.25 bis, and Dumb modes. It

determines how long the Modem attempts to handshake with a calling V.32

modem before falling back to a lower speed. The available T1 Timer settings

are 0, 0.3, 0.8, 1.6 and 3.0 seconds.

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Modem 34336

Normally, as part of the V.32 handshake, the calling modem begins sending

a sequence to the answer modem while the answer modem is still sending

answer tone. In this case, there is no T1 timer. However, the V.32

recommendation allows for a T1 time of up to 3 seconds, meaning that the

answer modem may be set to wait (before falling back) for up to 3 seconds.

The B option is available for all modes. If the Modem makes a connection at

one of the V.32 rates (4800 to 14,400 bps) or V.22 bis rate (2400 bps), it can

request that the remote modem send a retrain sequence.

• ENABLE — The modem requests a retrain sequence.

• DISABLE — The modem will not request a retrain sequence.

The Answer/Originate Default option is available for Hayes and Leased

modes (and manual originate/answer dial operation). It sets the Modem to

default to either answer or originate status.

• ANSWER — Sets the Modem to answer mode.

• ORIGINATE — Sets the Modem is set to originate mode.

The Answer Tone option is available for Hayes, V.25 bis, and Dumb modes.

The answer-tone frequency is selectable only if the maximum data rate is set

to 1200 bps (via the SPEED LIMIT menu), in which case the answer tone can

be set to either 2225 or 2100 Hz. Otherwise, the answer tone frequency is

2100 Hz (the standard for V.32 operation). In general, this setting should

not be changed (even for fallback with Bell standard modems, which use a

2225-Hz answer tone).

The Front Panel Control option is available for all modes. It controls the use

of the front panel. If disabled, the front panel of the modem will not respond

to changes to the Setup menus. Front Panel Control is a security feature

helpful in situations where it is undesirable for the modem’s configuration

to be changed.

Two speaker options are available: Speaker Control and Speaker Volume.

The Speaker Control option is available for all modes.

• ON — Speaker is on during the full modem handshake process and while

the unit remains on-line.

• OFF — The speaker is off; the call cannot be audibly monitored.

• ON TILL CD — Speaker remains on until a carrier signal (CD)

is detected.

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3.0 Modem Setup Options

The Speaker Volume option is available for all modes. It can be set to LOW,

MEDIUM, or HIGH.

The Guard Tones option is available for Hayes, V.25 bis, Dumb modes.

Guard tones are used in V.22 and V.22 bis modes only, to assure proper band

separation on systems that use international telephone circuits. Unless you

are using international circuits in one of these modes, you should turn the

guard-tone option OFF. If guard tones are required, their frequency can be

set to 550 Hz or 1800 Hz (the most commonly used guard-tone frequency).

V.13 Operation is available for V.25 bis, Dumb, and Leased modes

(synchronous operation only).

• OFF — V.13 operation is off. This setting allows normal full duplex

operation. (All other selections are for enabling V.13 operation.)

• TX ONLY — Status of RTS will be sent to remote modem.

• RX ONLY — Carrier Detect (CD) will be controlled by V.13 signals from

the remote modem.

• TX AND RX — Status of RTS will be sent to remote modem, and CD will

be controlled by V.13 signals from the remote modem.

To select one of the four V.13 options, press pushbutton 1 or 3 with the V13

screen displayed until the selection you want is displayed. For half-duplex

point-to-point applications, select TX AND RX. For multidrop applications,

select RX ONLY for all modems at the host site and TX ONLY for all

modems at the remote site. For further information on V.13 operation,

see Section 4.10.

3.3.8 V.33 AND BELL 208A/B OPTIONS

The following three options are available on the Modem only and are

intended only for V.33 or Bell 208A/B operation. (For Bell 208 operation,

see also the Satellite Delay and Turnaround Delay options.)

The Carrier Type option is available for V.25 bis, Dumb, Leased line modes.

• SWITCHED (SWITCH) — For 2-wire applications, the carrier type option

must be set for switched carrier operation.

• CONSTANT — Constant or continuous carrier can only be used for 4-wire

leased-line applications (although such applications may also use switched

carrier).

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Modem 34336

The CTS option is available for 4-wire Leased Line modes. It applies only

to 4-wire leased line applications using constant carrier.

• RTS — The CTS signal follows RTS.

• ON — CTS is always ON.

NOTE

The Modem also supports a CTS to EIA option, which is described earlier

in this chapter under EIA OPTIONS.

The RTS-CTS Delay (CTS Delay) option is available for V.25 bis, Dumb,

Leased line modes. The available RTS-to-CTS delay settings are 0, 15, 50,

or 150 ms. However, the only available choices for 208A/B operation are

50 and 150 ms. If you select 0 or 15 ms, the actual delay in 208A/B mode

will be 50 ms.

NOTE

RTS-to-CTS delay is not effective if the CTS option is set to ON (always

ON). For V.33 operation, RTS-to-CTS delay is effective only for 4-wire

leased line applications that use constant carrier.

The PHONE screen for storing a telephone number and Auto-Recovery

are discussed in Sections 4.2 amd 4.3.

The LCD Intensity option is available for all modes. It allows you to

use pushbutton 3 (for INC or increase) to darken characters on the

LCD or pushbutton 1 (for DEC or decrease) to lighten them.

3.3.9 OPTIONS ACCESSIBLE WITH SUMMARY SETUP ONLY

The twelve options described below can only be changed through the

modem’s Summary Setup feature, which is explained in Appendix C.

The Wait For Carrier option is available for V.25 bis, Dumb modes. The time

the modem waits for a carrier signal when origin-ating a call can be set for 30,

45, 60, or 75 seconds. (In Hayes mode, the wait-for-carrier time is determined

by the value in register S7.)

The Phase Reversal in Answer Tone option is available for all modes. When

enabled, the Phase Reversal in Answer Tone option signals the telephone

network to turn off its echo cancelers. For virtually all applications, phase

reversal should be enabled (the default setting).

The Satellite Delay option is available for 208 mode. It facilitates transmission

over satellite links (but does not permit fast-turnaround operation). When the

Satellite Delay option is on, RTS is inhibited for 275 ms after the answer tone

stops and after the DSR signal comes on. The delay occurs at both the

originating and answering modems, allowing the echo suppressors on the

telephone link to be enabled.

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3.0 Modem Setup Options

The Turnaround Delay option is available for 208 mode. It is intended for

circuits where echo is a problem. It prevents the Modem from receiving an

echo of its own transmitted data. When the Turnaround Delay option is on,

CD (pin 8) is held low for 150 ms after RTS is turned off. If the modem

detects an energy loss during the delay, it turns CD on 52 ms after detecting

the loss. If the modem does not detect an energy loss, it turns CD on 52 ms

after the end of the delay. The modem ignores any energy loss during the

first 8.5 ms.

The Analog Loopback Make Busy is available for all modes. If the Analog

Loopback Make Busy option is enabled, the Modem provides a busy

indication to the dial line interface when the Modem is in analog loopback

test mode.

The Selective Retransmission option is for Hayes,V.25 bis, Dumb, and Leased-

Line modes (except V.33). This option allows the Modem to communicate

with certain modems that are not able to respond to the MNP selective

retransmission command.

• Enable — This setting allows the modem to request retransmission

of a single information frame (in the event of a transmission error).

• Disable — Data can only be retransmitted in a series of information frames.

The DCE Pass-Through Flow Control option is for Hayes,V.25 bis, Dumb,

and Leased-Line modes (except V.33)

This option affects DCE–DTE flow control only. It is only effective if error

correction or buffer mode/speed conversion is ‘enabled’.

• Enable — The Modem will pass flow control characters received from

the remote modem to the local DTE.

• Disable — The Modem will not pass flow control characters from the

remote modem to the local DTE.

The Link Flow Control option is for Hayes,V.25 bis, Dumb, Leased-Line

modes (except V.33)

This option is effective only if buffer mode/speed conversion is enabled

and an error-correction link is not established.

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Modem 34336

• Enable — The Modem will check for X-ON/X-OFF (DC1/DC3)

flow control characters received from the remote modem to determine

whether to stop or start/restart data transmission to the remote modem.

A DC3 (or DC2) control character will cause the Modem/Modem 3242–S

to stop data transmission and hold data in its buffer until it receives a DC1

control character (which instructs the modem to resume transmission).

• Disable — The Modem will ignore X-ON/X-OFF (DC1/DC3)

flow control characters received from the remote modem.

• Slaved — Link flow control is controlled by the DCE-DTE Flow Control

option. If DCE-DTE Flow Control is set to NONE or CTS, Link Flow

Control is disabled. Otherwise, it is enabled.

The V.32 Mode option Hayes, V.25 bis, Dumb, and Leased-Line modes

(except V.33)

This option is used to select CCITT V.32 bis operation or V.32 extended

operation.

When V.32 bis mode is selected (factory-default setting), the follow-ing are

available: RRP (Rate Renegotiation Procedure); data rate of 7200 bps; RATE

screen that allows you to manually initiate RRP. RRP enables the modem to

auto-matically fall back or fall forward to a lower or higher data rate during

data transmission in response to changes in signal quality. Selecting V.32 bis

mode makes RRP available as an option; however, RRP will not function unless

it is enabled (the default setting is enabled.)

When V.32 bis mode is selected, a RATE screen is available from MAIN

MENU screen 3. The RATE screen can be used to manually initiate RRP

for diagnostic purposes. For additional informa-tion, see Section 7.6,

Diagnostic Monitoring: Status Screens.

When V.32 bis mode is selected, 7200 bps can be selected as the maximum

or minimum data rate (using the Speed Limit option). When V.32 bis is not

selected, 7200 bps operation is not available.

NOTE

By definition, V.32 bis operation includes the ability to operate at 12,000 and 14,400

bps. Therefore, only the Modem is a true V.32 bis modem. However, when the

V.32 bis mode is selected on the Modem 32192, it will support the following

options as well: RRP; 7200 bps data rate; the RATE screen.

The V.32 extended mode disables the V.32 bis features. In V.32 extended

mode, the Modem’s functional ability is identical to that of previous models

of this modem series (the MD833A model prior to incorporation of the

CCITT V.32 bis recommendation.)

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3.0 Modem Setup Options

The 208 Phase Detection option is for 208 mode.

• Normal — Conditions the modem’s 208 receiver for normal modulation

detection.

• Compensated — Conditions the 208 receiver for compensated

modulation detection for improved performance with older 208 modems.

The Answer Tone Detection is for 208 mode.

• Enable — Conditions the originating modem’s receiver to wait for answer

tone detection before going on-line.

• Disable — Conditions the originating modem to go on-line without

requiring answer tone detection. This setting accommodates operation

with automatic calling units that connect the modem to the line at the

end of answer tone.

The Multimode Handshake option is for Hayes, V.25 bis, and Dumb modes.

This option determines how long the Modem will attempt to handshake

with a V.32 modem before falling back to a lower speed.

• T1 Timer — If the T1 timer setting is selected, the modem will attempt

to handshake with a calling V.32 modem for the time specified by the T1

Timer option.

• V.32 bis ANNEX A — If the V.32 bis Annex A setting is selected, the

modem will handshake according to the conventions established in Annex

A of the CCITT V.32 bis recommendation. Handshaking using the Annex

A selection will generally be faster than handshaking based on the T1

timer.

NOTE

The T1 Timer option (Section 3.3.7, Modem Setups) is only effective if the

Multimode Handshake option is set to 0 (T1 timer).

Two additional options, Operating Mode Fallback and V.32 Speed Fallback,

are discussed in Section 4.9.

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Modem 34336

4.0 General Operation and

Special Features

This chapter describes the following Modem features and operational

modes (listed here in the order in which they are presented):

• Quick reset

• Dumb mode and Bell 208 operation

• Security operation

• Phone number storage

• Leased Line Auto-Recovery

• Dial Line Auto-Recovery

• DTR dialing

• Diagnostic interface control

• Automatic fallback

• V.13 operation

The status screens, which display data concerning the operational status of

the modem, are discussed in Chapter 7. Instructions for using the pushbutton

controls and LCD are included in Chapter 3.

4.1 Quick Reset

Quick Reset enables you to reset the modem without powering down the unit.

For a soft reset of the Modem—when option settings are not changed but the

modem is cleared for a new start, and the ROM memory chip is checked—

select RESET from MAIN MENU screen 3. The modem displays the power-on

screen for a few seconds. Then it displays the EIA status screen.

4.2 Phone Number Storage

This feature is used to store a number to be used later for autodialing from

the front panel, DTR dialing, or for leased line or dial line auto-recovery.

To store numbers in Hayes mode, see Chapter 5.

To store a number from the front panel, select PHONE from MODEM

SETUPS screen 5. The following screen is displayed:

- - - - - - - - -

DEC CTRL INC

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4.0 General Operation and Special Features

If a number has been previously stored, the number is displayed on the top

line of the LCD (instead of dashes, as shown above).

Only one phone number can be stored per cell. To store a phone number,

use the right and left arrow pushbuttons to go to the digit you want to change.

The character at the current cursor location flashes. Use pushbutton 1 to

decrease a number at the current cursor location or pushbutton 3 to increase

a number. Use pushbutton 2 (CTRL) to sequence through the dialing control

characters (listed below). Use the arrow pushbuttons to move on to the next

digit or character to be changed. The phone number is saved when you

return to the MAIN MENU.

4.3 Leased Line Auto-Recovery

When conditions on the leased lines deteriorate, the Leased Line Auto-

Recovery feature allows the Modem to automatically restore operation for

a leased line application by using dial lines as a backup. The Modem uses

signal quality and loss of carrier detect to determine if line conditions

are unsatisfactory. Leased Line Auto-Recovery is accessed via the AUTO-

RECOVERY screen on the front panel LCD. The following conditions

are required for Leased Line Auto-Recovery operation:

• Leased Line Auto-Recovery must be enabled (using the Leased Line Auto-

Recovery Select option) on both communicating modems.

• The Leased Line Auto-Recovery Select, Return and Test options must

be set correctly on both communicating modems, as explained in the

following sections.

• A dial backup line (or lines) must be installed.

• The phone number to be dialed (the backup line) must be stored

in the originate modem, as explained in the previous section.

• Auto-answer must be enabled on the answer modem.

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Modem 34336

Table 4-1. Dialing Control Characters.

Character

Function

A-D

Used in some PBX applications (tone dialing only).

Links a phone number to another number to be

dialed as an alternate.

Sets tone-dialing mode.

Sets pulse-dialing mode.

Configures modem for Dial Line Auto-Recovery.

Requires / prefix. See DIAL LINE AUTO-

RECOVERY section later in this chapter.

W or : (colon)

, (comma)

. (period)

- (dash)

(space)

Wait 30 seconds for dial tone before proceeding.

Inserts 4-second pause.

Marks end of phone number.

Used only for clarity (no function).

Used only for clarity.

Dial * (tone dialing only).

Dial # (tone dialing only).

A, B, C and D are used in some private branch exchange (PBX)

applications. The * and # symbols are sometimes used for access

to remote computer systems.

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4.0 General Operation and Special Features

4.3.1 AUTODIAL BACKUP

The Modem automatically dials the stored number to connect over the backup

line if it detects poor signal quality (ER) or a loss of carrier detect (CD) on the

leased line. The criteria used by the Modem in assessing the condition of the

leased line depend upon the settings of the Signal Quality option (one error

in 10³or 10⁵bits) and the Carrier Detect Level option (-43,

-33 or -26 dBm).

When Dial Backup occurs (either automatically or by operator intervention),

the following message flashes on the front-panel LCD of both modems:

ATTENTION:

DIAL BACKUP

The message clears when the modem returns to the leased line. If you want

to clear the message while the Modem is still in dial-backup mode, press

the ENT pushbutton.

4.3.2 EXIT FROM LEASED LINE AUTO-RECOVERY

If the Leased Line Auto-Recovery Return option is enabled (see below),

the Modem automatically exits the Auto-Recovery mode when leased-line

conditions are satisfactory. Any normal disconnects (such as loss of carrier

or line current) may also disconnect the dial connections and return

communication to the leased line. To ensure the proper disconnect

capabilities for Leased Line Auto-Recovery mode, both the line current

disconnect (CURRENT DISC’T screen) and carrier disconnect (CARRIER

DISC’T) options must be enabled on both modems. To manually exit the

Leased Line Auto-Recovery mode and return to leased line operation, select

DIAL from MAIN MENU screen 1, and then select HANGUP from the

AUTO-DIAL screen.

4.3.3 LEASED LINE AUTO-RECOVERY OPTIONS

Three options allow you to specify the criteria the Modem uses in

determining when to enter and exit the Leased Line Auto-Recovery mode:

• Leased Line Auto-Recovery Select (Select)

• Return From Leased Line Auto-Recovery (retn)

• Test Interval (Test)

The Leased Line Auto-Recovery Select option determines the type of Leased

Line Auto-Recovery desired. “DIAL IF BAD >> (1, 2, 3 or 4) min” means dial

backup occurs if bad line conditions are present for the number of minutes

selected. To disable Leased Line Auto Recovery, select NO AUTO

RECOVERY. A sixth option, Manual Recovery, is discussed below.

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Modem 34336

NOTE

If DIAL IF BAD >> (1, 2, 3 or 4) min is selected, the Select option setting

of the answer unit must be equal to or less than the Select option of the

originate unit.

If both modems are set for Manual Recovery, the originate unit is used to

autodial the number stored via the PHONE screen without having to change

the LINE TYPE setting on either unit. To autodial, access the AUTO-DIAL

screen and select DIAL. To return to the leased line, select HANGUP from

the AUTO-DIAL screen.

The Return From Leased Line Auto-Recovery option determines the criteria

for exiting the Leased Line Auto-Recovery mode.<D%0> “RETURN IF GOOD

>> (10, 40, 60, or 120) seconds” means the modem automatically exits the

Leased Line Auto-Recovery mode when it tests and finds the leased <M%-

2>line in good condition for more than the time period specified (10, 40, 60

or 120 seconds).<D%0> If the Return option is set to OFF, the modem stays

in the Auto-Recovery mode indefinitely, unless you select HANGUP from the

AUTO-DIAL screen, a loss of line current, or other normal disconnect occurs.

Either event returns communication to the leased line.

NOTE

The Return option setting must be the same on both communicating

units.

If the Return option is enabled (>> 10, 40, 60, or 120 seconds), the Test

Interval selections control how frequently the Modem tests the leased line

conditions to determine if exit from the Leased Line Auto-Recovery mode is

desirable. Exiting is based on the criteria selected for return from Auto-

Recovery. The Modem can be set to test every 10, 20, 40, or 60 minutes.

NOTE

The Test option setting must be the same on both units.

4.4 Dial Line Auto-Recovery

The Dial Line Auto-Recovery feature allows you to set up the Modem for a

dial-up application so it automatically redials to restore a broken connection

if the modem goes on-hook. In this way, the Dial Line Auto-Recovery feature

emulates the reliability of a leased line connection.

4.4.1 SETTING UP THE MODEM FOR DIAL LINE AUTO-RECOVERY

Two steps are required to set up the Modem for Dial Line Auto-Recovery.

First, enter or store the number to be dialed with the /R command. Then,

enable Dial Line Auto-Recovery. To configure the Modem for Dial Line Auto-

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4.0 General Operation and Special Features

Recovery from the front panel, enter the phone number to be dialed followed

by /R (the Dial Line Auto-Recovery command) on the PHONE screen

(shown below).

T555-4545/R

DEC CTRL INC

If you need assistance, see Section 4.2.

An alternate way to configure the Modem for Dial Line Auto-Recovery

(in Hayes mode only) is to use the Hayes AT &Z command to store the

phone number to be redialed and the /R command in memory location 0,

by entering the following command:

AT &Z0=T555-4545/R

Dial Line Auto-Recovery is not enabled until you select DIAL from the front

panel AUTO-DIAL screen. If power is removed from the modem, select DIAL

to re-enable Dial Line Auto-Recovery. To disable Dial Line Auto-Recovery,

select RESET from MAIN MENU screen 3.

4.4.2 RECOVERY PROCEDURE

If Dial Line Auto-Recovery is enabled and the Modem goes on-hook, it redials

the stored phone number up to 10 times. It redials 5 times at 30-second

intervals, waits 2 hours, and then redials 5 additional times at 30-second

intervals. The Modem stops redialing after 10 attempts.

If a connection is broken, re-established, and broken again, the full sequence

of 10 redial attempts does not occur unless the Modem is on-line for more

than 1 hour. The modem redials, but it is programmed not to exceed more

than 10 redial attempts in 1 hour.

4.5 DTR Dialing

NOTE

To use DTR dialing in V.25 bis mode, you must use the Summary Setup

feature, explained in Chapter 6.

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Modem 34336

4.5.1 DIALING A STORED NUMBER

DTR dialing allows you to set up the Modem to automatically dial a stored

number even when the autodialer is not enabled.

To enable DTR dialing, select DTR from the DIALER option screen. When

DTR dialing is enabled, an OFF-to-ON transition of DTR causes the Modem

to automatically dial the number previously stored using the front-panel LCD.

DTR must remain on for at least 50 ms to effect automatic dialing. A 50-ms

drop of DTR aborts the process or disconnects the call. When DTR goes high

again for at least 50 ms, the automatic-dialing process begins again.

4.5.2 ANSWER MODE OPERATION

If the Modem is set for DTR dialing, it automatically answers without DTR.

However, it will not transfer data until DTR goes high. The call may be

terminated by dropping DTR.

4.6 Dumb Mode And Bell 208 Operation

Bell 208 operation is available on the Modem only. For additional

information, see Section 2.4.6. Table 6-2 in Chapter 6 lists dialing parameters

that may be used to modify Dumb mode or Bell 208 dialing operations.

MANUAL ORIGINATE/ANSWER OPERATION

When the Modem is operating in Dumb mode or configured for Bell

208 operation, data calls may be manually originated from a phone set.

(Plug the phone into the Modem jack marked PHONE.)

For manual-originate operation, the remote modem may be configured for

either automatic or manual answer. For manual originate/answer operation,

one modem must be set to ANSWER and one must be set to ORIGINATE via

the ANS/ORG DEFAULT screen. For either type of operation, use the Dumb

mode or Bell 208 Quick Setup to configure the Modem. (The Dumb mode

Quick Setup defaults to asynchronous operation; the Bell 208 Quick Setup

defaults to synchronous operation.)

Either Quick Setup sets the Modem to originate mode. If you want to set your

Modem to answer mode, use the front-panel controls to access the ANS/ORG

DEFAULT screen (MODEM SETUPS screen 4). Then, select ANSWER

(answer mode). To manually originate a data call, select TALK from MAIN

MENU screen 1. The MANUAL-DIAL screen is displayed. Select TALK again.

This puts the Modem in talk mode. Lift the handset and listen for the dial

tone. Dial the phone number of the remote modem. When you hear a high-

pitched answer tone, select DATA from the MANUAL-DIAL screen, and

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4.0 General Operation and Special Features

place the handset back on the cradle. The LCD displays the status of the

communication. It appears as shown below.

D TR MR RS CS

9600

The data link between the two modems is now established, and data transfer

begins.

An incoming call may be answered manually or automatically. To answer a

data call manually, you must disable the Auto-Answer option. Before the call

is received, the Modem must be set to TALK, as explained in the previous

section. The first unit that is switched to DATA mode must be set for answer

mode (using the answer/originate option). The other unit must be set for

originate mode.

NOTE

If you set the Modem to talk mode, the phone rings, but the Modem will

not answer, even if the Auto-Answer option is enabled.

After you answer the phone and initiate a conversation with the caller, the

Modem must be set for data mode. With the MANUAL-DIAL screen still

displayed, select DATA to put the Modem in data mode.

The first person to go to data mode hears his telephone disconnect as his

modem connects. The other person must wait until he hears an answer tone,

and then switch to data mode (select DATA). When both modems are in data

mode, the data communication begins. The LCD displays the status of the

connection.

There are several ways a data call can be terminated. You can terminate a call

through communication software by following the software manufacturer’s

instructions. An alternate method is to switch to the TALK option (talk

mode) on the MANUAL-DIAL screen, as described in the previous section.

Or you can drop the DTR signal from the DTE (by software control or by

turning the DTE off).

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Modem 34336

4.7 Modem Security Operation

In 2-Wire-Dial Hayes emulation mode only, the Modem can be configured to

provide security on incoming calls. Remote users attempting to connect to the

Modem are required to enter a password. Incoming calls are accepted only if

the user enters a valid password.

NOTE

The security features described in this manual provide a deterrent to

unauthorized access. No communications system can be made perfectly

secure.

PASSWORD PROTECTION

NOTE

Password protection functions only if the Modem is in Hayes emulation

mode, error correction and/or buffer mode are enabled, and the data

format is asynchronous.

In Hayes mode only, the Modem can be configured for two types of security

operation: security callback or password pass-through operation. Both types of

security operation provide security on incoming calls by requiring remote

users to enter a valid password. In addition, access to Hayes compatible

commands for viewing and storing phone numbers is password-protected.

If callback operation is enabled, the Modem calls back an authorized user

after he or she enters a valid password. If pass-through operation is enabled,

the Modem passes a connection on to the DTE interface only after it receives

a valid password.

The password-protection scheme used by the Modem for incoming calls is

summarized below.

• A remote modem calls the local Modem.

• Local Modem answers.

• Remote user sends carriage return [CR].

• Local Modem sends PASSWORD? query, displayed on remote terminal.

• Remote user sends unique password (assigned to remote modem).

• Local Modem confirms password and, according to the password, grants

access (if programmed for pass-through operation) or initiates security

callback.

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4.0 General Operation and Special Features

The modem’s security configuration for password protection is controlled

from the DTE by a special set of password commands. The commands are

implemented by using the Hayes AT &Z command to store them in memory.

If an administrative password is implemented, the AT &Z command will not

function until it is unlocked.

The Modem incorporates 10 memory locations for storing telephone

numbers, passwords, and the password commands listed in Table 4-2. To

implement a security command, use the Hayes AT &Z command to store the

command in a specific memory location. The password commands are listed

in Table 4-2 and explained in detail in the sections that follow.

Table 4-2. Password Commands

COMMAND FUNCTION

EXAMPLE¹

MEM.LOC.²

Set/change administrative

password; password-

protects use of certain

Hayes commands.

/ASECURITY

/PYELLOW

Set password for

pass-through

operation or

security callback

operation

4443535/PGREEN

2-49

User-defined text string.

Used to send a response

to the remote terminal

user after a valid

password is received.

/UCONNECTED

¹Command string stored using AT &Z commands.

²Each command will function only in the listed memory locations.

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Modem 34336

Rules for using passwords and password commands are listed below.

• Memory locations 0 and 2-9 may be used for storing phone numbers;

locations 2-9 may be used to store passwords.

• The entire command string, including the AT &Z command,

cannot exceed 40 characters.

• Passwords and commands may be entered in capitals or lowercase letters.

They are stored and displayed as capitals.

• For password pass-through operation, / must be the first character in

a storage location. For security callback operation, a phone number

must be listed first in a storage location.

• Special characters (! @ ? , etc.) may be used for passwords entered with

the DTE interface, but these characters cannot be entered with the

Modem's front panel.

• A phone number cannot be stored after / .

• Only one command (/A, /P, or /U) can be stored in each memory

location.

• Do not leave a space after a command.

• When using the /U command, do not include spaces or control characters

in the specified text string.

The following instructions explain how to use the password commands.

1.Establishing or changing the administrative password. For greatest

security, you should use an administrative password. If implemented,

the administrative password controls access to the Hayes compatible &V

and &Z commands. The commands are required to view or modify the

modem’s security configuration (as explained in the following sections).

To establish or change an administrative password enter the following

command replacing SECURITY with your password:

AT &Z1=/ASECURITY

NOTE

The administrative password may be stored only in memory location 1.

The command line, including AT &Z1=, cannot exceed 40 characters.

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4.0 General Operation and Special Features

2.Unlocking the &V and &Z commands. If an administrative password is

implemented, the Hayes compatible &V and &Z commands cannot be

accessed unless they are first unlocked using the current administrative

password. (&V is used to view the active modem configuration, stored

phone numbers, password commands and passwords; &Z is used to store

phone numbers, password commands and passwords). To unlock the

&V and &Z commands, enter the following command; substituting

your password for SECURITY:

AT &Z1=/ASECURITY

The &V and &Z commands are accessible. To re-lock the &V and &Z

commands, enter AT Z. The DTE responds with OK, and the &V or &Z

commands will not function until they are unlocked.

3.Programming security callback operation. Use the commands AT& Z and

/P to specify the callback phone number and password to be used. The

following example programs memory location 3 for callback operation:

AT &Z3=T5551212/PVIOLET

The callback number in this example is 555-1212 (with T used to specify

tone dialing); the password is VIOLET. A remote user can now call from

the specified callback number, 555-1212. After the modems connect, the

remote user presses the Enter key. The DTE prompts the user to enter

the assigned password by displaying the PASSWORD? query. Upon

receipt of the correct password, VIOLET, the local Modem calls back the

remote user at 555-1212. Once this connection is established, data may

pass freely.

NOTE

Callback numbers and passwords may be stored only in memory

locations 2 through 9.

4.Programming pass-through operation. Use the commands AT &Z and /P

to specify the password used for pass-through operation. The following

example programs memory location 5 for pass-through operation:

AT &Z5=/PYELLOW

The password is YELLOW. The DTE prompts the user to enter the

assigned password by displaying the PASSWORD? query. If the user

enters the correct password, YELLOW, the call is connected.

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Modem 34336

NOTE

Passwords may be stored only in memory locations 2 through 9.

5.Programming a response to a correct password. Enter the following

command, replacing CONNECTED with your message:

AT &Z0=/UCONNECTED

The DTE responds with the specified message when the modem receives

a correct password.

NOTE

The /U command and message can be stored only in memory location 0.

4.8 Modem-Controlled Remote Control

Certain modems can be used to remotely control other modems. Alternately,

modems may be remotely controlled from a computer or other DTE. This

section explains modem-controlled remote control. Remote control from a

DTE is explained in Section 4.9.

Two types of modem-controlled remote control are possible:

• Direct modem-to-modem control—One modem can be used to control

the front panel of another modem through a phone link.

• Control through a rack controller—A modem in a rack enclosure equipped

with an intelligent rack controller can control:

Another modem in the same rack or

A remote modem connected to any modem in the rack.

For both types of remote control, the controlling modem and the controlled

(remote) modem must be connected at a data rate that uses trellis coding.

(This does not apply, however, if both modems are installed in the same rack

and the rack is equipped with a rack controller.)

4.8.1 DIRECT MODEM-TO-MODEM REMOTE CONTROL

REMOTE screen 1 on the LCD allows you to use one Modem 34336 to

control the front panel of another Modem 34336 via a phone link. (REMOTE

screen 2 is discussed in Section 4.8.2.)

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4.0 General Operation and Special Features

Control Procedure (Modem-to-Modem)

Enabling Modem-to-Modem Remote Control Mode

To remotely control a modem connected by a direct phone link,

access REMOTE screen 1 (shown below).

REMOTE

CONTROL

<1>

TEST

If you select CONTROL, you will be able to control the front panel of the

remote modem from the front panel of the modem you are using. When

you select CONTROL, you will see (on the LCD of the modem you are using)

whatever is currently displayed on the LCD of the remote modem. The

characters on the LCD will be displayed in lower case—this is to let you

know you are actually looking at a “copy” of the LCD of the remote modem.

Buttons pressed on the front panel of the controlling modem will affect the

controlled modem (and not the controlling modem). When you are remotely

controlling another modem, the LCD will not change as quickly as it normally

does.

NOTE

While a Modem 34336 is being remotely controlled by another Modem

34336 or is remotely controlling another Modem 34336, its diagnostic

port cannot be used for other purposes—commands from the diagnostic

port will be ignored.

(You can also access two remote test options from REMOTE 1 screen by

selecting TEST. These test options, remote digital loopback and remote

digital loopback self test, are described in Chapter 7.)

Exiting from Remote Control Mode

To exit from remote control mode, press the ENT pushbutton five times in

succession on the front panel of the controlling modem. (If the remote

modem resets as a result of a configuration change, the local modem will

appear to have no control. To remedy this situation, press the ENT button

five times.)

4.8.2 REMOTE CONTROL THROUGH A RACK CONTROLLER

When installed in a rack enclosure equipped with an intelligent rack

controller, the Modem 34336 can be used to control:

• Another modem in the same rack or

• A remote modem connected to any modem in the rack (address control

mode only).

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Modem 34336

Remote control through a rack controller is an especially valuable capability

for modem used in high-density 16-slot enclosures. The low-profile modems

specially designed for these racks are manufactured without an LCD user

interface or control pushbuttons. One way to access the low-profile modems

to monitor, test, or configure tham is by using the modem-control feature

described below.

The controlling modem must be a Modem 34336 equipped with a front-panel

LCD and pushbuttons. (Low-profile rackmount versions of these modems

cannot be used as controlling modems because they do not have LCDs and

pushbuttons.) The controlling Modem 34336 can control another Modem

34336.

Control Procedure (Using a Rack Controller)

Enabling Remote Control through a Rack Controller

The main screen used to control other modems through a rack controller

is REMOTE screen 2 (shown below).

REMOTE

<2>

CONTROL ADDR/C ADDR

This screen is used as follows:

1. Select address control or slot control—To control a modem in the

same rack as the controlling modem, or to control a connected remote

modem, you must first specify the address or slot number (location in

the rack) of the modem you want to control. If you want to specify the

modem by its address, select ADDR/C (address control) on the bottom

line of REMOTE screen 2.

NOTE

Each modem must have a unique address.

If you want to specify the modem by its slot number, select SLOT/C.

(For slot 16, use 00 or 16, whichever is displayed on your modem.) Press

pushbutton 2 to toggle between ADDR/C and SLOT/C (slot control).

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4.0 General Operation and Special Features

2. Enter the address or slot number—To enter the address or slot number

of the modem to be controlled, press pushbutton 3. If ADDR/C is

displayed on REMOTE screen 2, a screen showing ADDRESS: 000,000 on

the top line will be displayed. If SLOT/C is displayed on REMOTE screen

2, a screen showing SLOT NUMBER: 01 on the top line will be displayed.

Enter the address or slot number as follows: Use the right and left arrow

pushbuttons to go to the digit you want to change. Then use pushbutton

1 to decrease (DEC) a number or pushbutton 3 to increase (INC) it.

If SLOT/C is selected, only modems in the same rack as the controlling

modem may be specified (slots 1–16). However, if ADDR/C is selected,

you can specify any modem in the same rack with the controlling modem

or a remote modem connected to any modem in that rack (Figure 4-1).

The remote modem may be in a rack without a rack controller, or it may

be a standalone modem.

When the address or slot number you want is shown, press ENT. The LCD

will return to REMOTE screen 2.

3. Initiate control—After entering the address or slot number of the modem

to be controlled, select CTRL from REMOTE screen 2. “CTRL” will flash

on and off for about seven seconds until the connection to the specified

modem is made. When the connection is made, all characters on the LCD

of the controlling modem will be in lower case instead of capitals—this

indicates that the screens displayed are for the controlled modem.

Buttons pressed on the front panel of the controlling modem will affect

the controlled modem (and not the controlling modem).

If the specified modem is not present or is not working, the LCD will

display a “NO RESPONSE” message. If a rack controller is not installed

on the rack enclosure or is not working, “CTRL” will continue to flash

on and off indefinitely (until you exit from the address or slot control

mode).

Exiting from Remote Control Mode

To exit from the address or slot control mode, press the ENT button five

times in succession. (If the remote modem resets as a result of a configuration

change, the local modem will appear to have no control. To remedy this

situation, press the ENT button five times.)

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Modem 34336

Modems in rack equpped

with rack controller

This modem, with LCD

pushbuttons, can control any

of the shaded (gray) modems.

Modems in rack with or

without rack controller

Standalone modems

Figure 4-1. Remote control—address control mode.

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4.0 General Operation and Special Features

4.9 Diagnostic Interface Control

The diagnostic software built into the Modem supports a special set of

commands known as diagnostic port commands. The commands (listed

in Table 4-3) are used to configure modems (from either a local or remote

location), or to monitor modems for diagnostic purposes. The diagnostic

port commands are entered from a computer or terminal keyboard.

NOTE

To configure or otherwise control a remote modem, the data rate must be

9600 bps or higher.

4.9.1 DIAGNOSTIC PORT

The Modem’s diagnostic port is an 8-pin RJ-45 connector allowing you to

test or configure the Modem from a connected computer or other DTE.

The location of the diagnostic connector next to the power connector on

the modem’s rear panel is shown in Figure 2-1. The diagnostic connector

requires a cable with an RJ-45 modular connector on one end (modem) and

a DB25 connector on the other (terminal) end. The pin assignments of this

connector are shown below.

Function

Constellation X output

Constellation Y output

Not used

Ground

Receive data (output from

modem)

Transmit data (input to

modem)

Not used

4.9.2 DIAGNOSTIC PORT COMMANDS

The diagnostic software built into the Modem supports the diagnostic port

commands listed in Table 4-3. These commands are issued from a computer

or other DTE, which must be connected to the modem’s diagnostic port.

To communicate with a modem via the diagnostic port, the DTE must be

configured for 8-bit character length, no parity, 1 stop bit, and a data rate

of 9600 bps.

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Modem 34336

Table 4-3. Diagnostic Port Commands.

COMMAND

FUNCTION

CONNECT g,u Connect to diagnostic port of modem at group address

g, unit address u. An address must be specified unless

the wildcard character * is used: CONNECT *

(meaning Connect to local modem; address

unknown/unspecified.). When the connection is made,

the DTE displays the modem’s address. Echo, line

feed, and Auto-Display are enabled.

CON g,u

CON performs same functions as CONNECT

command, except that echo, line feed, and Auto-

Display are disabled. The wild card character * may be

used: CON * .

NOTE: The remaining commands listed in this table will function only if

CONNECT or CON (with address or *) has been previously issued.

Displays the current front-panel LCD screen of the

connected modem on the DTE monitor.

Performs same function as front panel ENT button.

(Exits from screen.)

1, 2, or 3

> or .

< or ,

RESET

FRESET

Performs same functions as corresponding buttons on

front panel. (Selects choice 1, 2, or 3 from LCD.)

Performs same function as right arrow on the modem

front panel. (Displays next menu screen.)

Performs same function as left arrow on the modem

front panel. (Displays previous menu screen.)

Resets the Modem without changing option settings.

(Same as selecting RESET from the MAIN MENU.)

Resets the Modem to factory defaults. (Reconfigures

modem to Hayes mode default settings).

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4.0 General Operation and Special Features

A carriage return [CR] is required at the end of a command line except

when the command line consists of only one single-character command.

Commands can be entered in upper or lower case.

Other diagnostic port commands are available for factory use only.

Therefore, some commands that are not listed above may produce

a response.

When an address is specified with the CONNECT or CON command,

leading zeros are ignored, meaning that any of the following forms will work:

CONNECT 3,22

CONNECT 003,022

CON 000003,22

If a group or unit address is not specified, it is assumed to be zero:

CONNECT, 3 (same as CONNECT 0,3). Note that a comma is required,

even if no group or unit number is used.

4.9.3 RESPONSES TO DIAGNOSTIC PORT COMMANDS

In response to the diagnostic port commands listed in Table 3-3, the

Modem may display the responses listed in Table 4-4 on the DTE monitor.

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Modem 34336

Table 4-4. Responses To Diagnostic Port Commands.

RESPONSE

ERROR

MEANING

Command error (incomplete, wrong syntax, etc.). (If

CONNECT or CON is issued without an address or *, the

modems will not connect, and there will be no ERROR

message.)

ADDRESS g,u The Modem has connected with diagnostic port of modem

at address g,u (group and unit). Address may be

preceded by A, S, or both—see below.

One or more modem alarms has been detected. An alarm

indicates a condition that may require attention (power

loss, loss of carrier, etc.).

Valid statistics have been collected on a call or attempted

call. Statistics include information such as call duration

call, signal quality level, etc.

RESET

Response to RESET command. Prompt ( >) appears when

reset is complete.

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4.0 General Operation and Special Features

4.9.4 DTE DISPLAYS

When Auto-Display is enabled, an update of the LCD is automatically

displayed on the DTE screen each time a command (E, 1, 2, 3, left arrow,

or right arrow) is entered to control the front-panel LCD on the connected

modem. Auto-Display is enabled when the long-form connect command

(CONNECT) is used.

Auto-Display is disabled when the CON command is used. However, even

with Auto-Display disabled, the D command can be used to display the LCD

screen.

The CONNECT command also enables echo and line feed on the DTE

screen, whereas both are disabled when CON is used. Data from the

connected modem is easier to read when CONNECT is used; however,

data throughput is faster if CON is used.

On the Modem’s front-panel LCD, a selected option flashes so it is easily

identified as the current selection. When an LCD display is sent to the DTE

in response to the CONNECT command, characters flashing on the LCD

are indicated on the DTE screen by asterisks. An asterisk appears below each

flashing character. In the example below, the selected CTS to EIA option

is TRUE.

Actual LCD on connected modem:

CTS to EIA

NORM RTS TRUE

DTE display:

CTS to EIA

NORM RTS TRUE

****

Asterisks denoting flashing characters are also displayed if the D command

is used to request a display of the LCD—provided the connect command last

used was CONNECT and not CON. Even when the CON command is used

(meaning the LCD of the connected modem is not automatically displayed),

a computer reading data from the diagnostic port is able to determine which

characters are flashing because bit 7 (MSB) is set in each flashing character.

4.9.5 DISCONNECTING FROM A DIAGNOSTIC LINK

There are two ways to disconnect from a modem-DTE diagnostic link:

• If you want to connect to another modem, issue the CONNECT command

followed by the address of the modem to which you want to connect.

The DTE disconnects from the first modem and immediately connects

to the one you specified.

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Modem 34336

• If you want to disconnect from the diagnostic link without establishing

a new link, issue the CONNECT command without an address.

4.10 Automatic Fallback

The Modem incorporates two automatic fallback features that are controlled

by the user:

• Operating Mode Fallback—Provides compatibility with modems that use

any of several different operating modes.

• V.32 Speed Fallback— Allows the Modem to automatically select the

highest possible data rate, depending on the signal quality during

handshake.

Both of the above fallback features function when the modem is in either

manual or automatic originate mode, or manual or automatic answer

mode.

4.10.1 OPERATING MODE FALLBACK

This section applies to dial-line operation only.

When the Modem originates or answers a call, it determines from the

handshake routine with the other modem the most efficient operating mode

that is supported by the other modem and automatically falls back to that

mode. The Modem supports two alternatives for operating mode fallback:

V.22 bis/Bell 212A/Bell 103 fallback operation (default setting) and V.22

bis/V.22/ V.21/V.23 fallback operation. For communication within the

United States, use the default setting for Operating Mode Fallback: V.22

bis/Bell 212A/Bell 103.

To configure the modem for V.22 bis/V.22/V.21/V.23 fallback operation,

refer to Appendix C. Follow the instructions given there to change the value

identified in the MISCELLANEOUS OPTIONS diagram (Appendix C) as

the Operating Mode Fallback parameter from 0 (default setting) to 1.

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4.0 General Operation and Special Features

Changing the Operating Mode Fallback parameter to 1 has the following

effects:

• The Modem is configured for V.22 bis 2400 bps/V.22 1200 and 600

bps/V.21 300 bps/V.23 1200/75 bps fallback operation. As a result,

600 and 1200/75 bps appear as additional selections on the SPEED

LIMIT LCD screens.

• Fallback to V.22 bis Bell 212A and Bell 103 compatibility is disabled.

• An AT command is available (in Hayes mode only) that allows control

over operating mode as follows: F0—Multi-mode operation (default);

F1—V.21, 300 bps; F2—V.22, 600 bps; F3—V.23, 1200/75 bps; F4—V.22,

1200 bps; F5—V.22 bis, 2400 bps; F6—V.32 (highest common speed).

Except for multi-mode operation, the mode and speed are limited to the

mode and speed specified. Multi-mode operation allows the modem to

automatically fall back to the most efficient mode that can be used by

both modems.

The preferred mode is V.32 (9600 or 4800 bps, asynchronous/ synchronous,

full duplex); however, if the other modem does not support the V.32

standard, the Modem falls back to one of the modes listed below. The fallback

modes are listed in the order in which they are attempted by the Modem in

normal operation.

Table 4-5. V.22 bis/BELL 212A/BELL 103 FALLBACK (DEFAULT).

MODE

DESCRIPTION

V.22 bis

Bell 212A

Bell 103

2400 bps asynchronous/synchronous

1200 bps asynchronous/synchronous

0-300 bps asynchronous

All modes are full duplex.

If V.22 bis/V.22/V.21/V.23 fallback operation is enabled, the following

fallback modes are available. As in the previous list, the modes are listed

in the order in which they are attempted by the Modem.

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Modem 34336

Table 4-6. V.22 bis/V.22/V.21/V.23 FALLBACK.

MODE

V.22 bis

V.22

DESCRIPTION

2400 bps asynchronous/ synchronous

1200 and 600 bps asynchronous/synchronous

300 bps asynchronous

V.21

V.23

1200/75 bps asynchronous

All modes are full duplex.

The operating mode is controlled through the SPEED LIMIT screens on the

LCD in all modes except Hayes mode. See Chapter 3 for details.

4.10.2 V.32 SPEED FALLBACK

This feature applies only to V.32 mode operation. It functions only if enabled

and the maximum speed is set (via the Speed Limit option) to the highest

available speed—9600 bps for the Modem, 14,400 bps for the Modem.

When V.32 Speed Fallback is enabled, the Modem automatically selects the

highest possible data rate, depending on the signal quality during handshake.

The Modem automatically selects either 9600 bps or the fallback rate of

4800 bps. The Modem selects either 14,400 bps or the fallback rate of

12,000 bps. If the error rate is one error in 1000 bits or lower, the Modem

connects at the highest available rate. If the error rate exceeds this threshold,

the Modem connects at the fallback rate. Fallback may also occur during

retrain sequences.

To configure the modem for automatic V.32 Speed Fallback, refer to

Appendix C. Follow the instructions to change the value identified in the

DATA PUMP OPTIONS diagram (Appendix C) as the V.32 Speed Fallback

parameter from 1 (default setting) to 0.

Rate Renegotiation Procedure (RRP)

Rate Renegotiation Procedure (RRP) is a third type of automatic fallback;

it can be controlled by the user.

Like V.32 Speed Fallback, RRP allows the Modem to automatically select the

highest possible data rate, depending on the signal quality. Unlike Speed

Fallback, RRP allows for data rate fallback or fallforward at any time during

data trans-mission. Retraining is not required. RRP may be used with either dial-

up lines or leased line operation.

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4.0 General Operation and Special Features

If Rate Renegotiation Procedure (RRP) is enabled, the modem will

automatically fall back or fall forward to a lower or higher data rate in

response to changes in signal quality. This may happen at any time during

data transmission, and it is done without a retraining procedure. Your data

transmission is virtually uninterrupted.

Note that data-rate adjustments are limited:

• to the range of 4800 to 14,400 bps for the Modem

(4800 to 9600 bps for the Modem 3242–S)

• by the minimum and maximum rate settings of the Speed Limit option.

If satisfactory performance cannot be attained at any of the available data

rates, the Modem will initiate a GSTN cleardown (line disconnect). If the

originate modem attempts to negotiate a rate that is lower than the minimum

rate setting of the answer modem, the answer modem will initiate a GSTN

cleardown.

How to Enable or Disable RRP

NOTE

RRP will function only if Speed Fallback is enabled (factory default) and

if the V.32 Mode option is set to V.32 bis (factory default). Both functions

are Summary Setup options.

The factory-default setting for RRP is enabled. To change the RRP option,

refer to the DATA PUMP OPTIONS diagram in Appemdix C. Change the

Rate Renegotiation Procedure (RRP) parameter shown in the diagram to 0

(disable) or 1 (enable). This is the only way the RRP option can be changed.

Rate Change Screen

If V.32 bis mode and the Rate Renegotiation Procedure (RRP) option are

both enabled, the Modem will automatically adjust during data transmission

to a higher or lower data rate, depending on the receive signal quality. For

diagnostic purposes, the RATE screen (accessed from screen 3 of the MAIN

MENU, as illustrated below) may be used to manually initiate speed renego-

tiation from the front panel, as explained below.

NOTE

The RATE screen is only displayed if V.32 bis mode is enabled

(via Summary Setup, V.32 Mode option).

If you select DOWN from the RATE screen, the Modem will fall back to the

next-lower speed. If you select UP, the modem will fall forward to the next-

higher speed if the signal quality is good enough. Remember, the data-speed

range within which the Modem can fall forward or fall back is limited by the

minimum and maximum rates set via the Speed Limit option.

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Modem 34336

After you select UP or DOWN, the LCD will automatically switch to the EIA

status screen so you can see the result of the rate-change request (i.e., the

current data rate, which is displayed in the lower left corner of the EIA status

screen). However, if the Modem has reached the minimum or maximum

speed, it will not switch to the EIA status screen.

NOTE

A request to increase the data rate may result in no change in the data

rate if the signal quality is poor.

If you manually initiate speed renegotiation with RRP enabled, the modem

will automatically renegotiate the speed (again) after four seconds. If the

originate modem attempts to negotiate a rate that is lower than the minimum

rate setting of the answer modem, the answer modem will disconnect (GSTN

cleardown).

4.11 V.13 Operation

The Modem can be configured for CCITT V.13 operation (which emulates

half- duplex operation) for either point-to-point or multidrop applications.

(The correct options for these applications are identified in Chapter 2.) The

Modem normally operates in full duplex; however, some applications (such as

certain network environments) may require control of a remote CD signal by

a local Request to Send (RTS) signal. V.13 operation allows local RTS control

of a remote CD signal without actual ON-OFF switching of the modem

carrier.

The following paragraph explains how the Modem responds to RTS signals

when it is configured for V.13 operation.

When RTS is raised HIGH by the terminal, the V.13 ON PATTERN is sent.

The Modem then raises CTS and data can be sent. When RTS is brought

LOW, the V.13 IDLE PATTERN is sent, and the Modem drops CTS. (If V.13

TX is enabled but the Modem's data pump is not ready to send, i.e., if it is

training or retraining, raising RTS causes CTS to be raised, but the V.13 ON

PATTERN is not sent.) When V.13 RX is enabled, CD turns ON if the V.13

ON PATTERN is detected; CD turns OFF if the V.13 IDLE PATTERN is

detected or if the Modem retrains, loses carrier, or is reset.

RATE

DOWN

MAIN MENU <3>

RESET RATE

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5.0 Hayes Emulation Mode

For easy reference, the following tables appear consecutively at the end of this

chapter:

• Table 5-1. Hayes Compatible Commands

• Table 5-2. Hayes Mode Result Codes

• Table 5-3. S Register Functions

5.1 Hayes Mode Autodialer

When the Hayes emulation mode is enabled, the Modem emulates a Hayes

autodialer and functions like a Hayes modem. Commands are issued from

the computer keyboard (or other DTE), and the Modem is compatible with

software written to drive a Hayes style AT command set.

5.1.1 ENABLING THE HAYES MODE AUTODIALER

You can enable the Hayes mode autodialer either by using the Quick Setup

feature or by selecting HAYES from the DIALER screen:

• Quick Setup. If you use the Quick Setup feature to select 2-Wire Dial

(Hayes), the Hayes mode autodialer is enabled, and all modem options

are automatically set to a preset configuration suitable for typical Hayes

mode applications. To select the 2-Wire Dial (Hayes) Quick Setup,

access QUICK SETUP screen 1 on the LCD and press pushbutton 2.

• Dialer Mode. If you enable the Hayes mode autodialer using the Dialer

Mode option, no other options are changed. Select DIALER from SETUP

screen 2. Then, select HAYES from the DIALER screen.

5.1.2 COMMAND GUIDELINES

The following guidelines for using Hayes compatible AT commands also

provide a summary of the fundamentals of Hayes mode autodialer operation.

Note that although carriage returns are not shown in the examples in this

chapter, a carriage return is required at the end of each command line.

• Escape Sequence (+++). The escape sequence causes the modem to

escape from the data transfer mode so it can interpret commands.

(Alternate characters for the escape sequence can be assigned via S

• Attention Code. AT, the attention code, must begin all command lines.

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Modem 34336

• Command Sequence. For dialing, a command line begins with AT,

followed by a D and the phone number. Other commands should be

placed before the dial command—or after the dial command if it is

terminated with a semicolon. See the example below:

AT M2 V1 D 555-1212; S2=1O

The above command instructs the Modem to keep the speaker on (M2),

send word result codes (V1), dial (D) 555-1212, end dial command, set

Characters not in the command set are ignored during the dial

command. Therefore, you can include punctuation or spaces in

the telephone number for easier reading. See the example below:

AT DT 9,(212)555-1234 or

AT DT 9, 212 555 1234

• A/ Command. Repeats the commands included in the previous command

line. Because the AT is also repeated, no AT is needed to begin this

command, nor is a carriage return needed. A/ is useful for redialing

a telephone number.

• Backspace Key. The backspace key deletes the last character entered

(provided there is no intervening carriage return) and is used for simple

editing.

• Carriage Return [CR]. A carriage return is required at the end of a

command line. The modem will not execute a command without it. A

carriage return is sent from the DTE keyboard. A period, which may be

entered via the modem’s front panel (PHONE LCD screen), has the same

function as a carriage return. (On most keyboards, the carriage return

[CR] key is labeled Enter or Return.)

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5.0 Hayes Emulation Mode

• Dial Command Modifiers. Several modifiers can be used with the

basic D (dial) command to alter dialing operations. The modifiers

are explained below.

Dial Command Modifiers:

L — Links a phone number to another number to be dialed as an

alternate

P — Sets pulse-dialing mode

S=m — Dial number stored at memory location m

T — Sets tone-dialing mode

W or : (colon) — Wait for dial tone before proceeding

, (comma) — Pause for 2 seconds

; (semicolon) — Return to command state after dialing

@ — Wait for silence

! (exclamation) — Flash

With few exceptions, dial-command modifiers function only if they are

used in a command line with the D command, or if they are included

in a stored number. A carriage return or period must be used at the

end of a dial string.

An example of a command line with two dial modifiers is shown below.

AT DT 9,555-1212

The modifier T instructs the modem to tone-dial. The comma instructs

the modem to pause after dialing 9 before it dials the remaining digits.

• Missing Parameter. A missing parameter is interpreted as a zero.

For example, the E command (echo) can be sent as either E0 or E1,

but if an E alone is sent, the Modem interprets it as if an E0 was sent.

• Command Buffer. The command buffer holds a maximum of 40

characters. If the command line exceeds 40 characters, the modem

refuses to execute any portion of the command line and sends an error

message. The AT at the beginning of the command line, control

characters, and spaces do not take up space in the command buffer.

Punctuation (except for spaces) does take up space in the command

buffer.

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Modem 34336

5.1.3 RESULT CODES

Result codes (see Table 5-2) are messages sent by the modem to the DTE

monitor in response to your commands. Result code options are selected

using the V and X commands, as explained below.

Result codes may be words (V1 command) or digits (V0). Word codes are

preceded and followed by a carriage-return, line-feed sequence. Digit codes

are followed by a carriage return. The result codes and their meanings are

summarized below:

Result codes 0-4 comprise the basic result code set: OK, CONNECT, RING,

NO CARRIER, and ERROR. Codes 5-43 provide additional response

information, as explained in Table 5-2. Various combinations of these codes

can be enabled or disabled by using the X command and its four parameters.

5.1.4 TRANSMISSION SPEED

Transmission speed is governed by the speed of the system with which you

wish to communicate. You must set the transmission speed of your computer

by setting a switch in the hardware or by issuing a software command. (Refer

to your computer documentation.) When the Modem originates a call, it

automatically detects and adjusts to the transmission speed set when the

communication port was initialized.

When answering a call, the Modem determines the transmission speed from

the carrier signal of the originating modem. Change the setting of your

equipment to match that of the remote system. Other-wise, unintelligible

data appears on your screen. (Depending on the parameter used with the

X command, the speed is indicated by the CONNECT response code.)

When a call is originated in Hayes mode, the AT attention code causes the

Modem to autobaud and override any front-panel Speed Limit or DTE Speed

settings. The speed at which the Modem autobauds defines the speed limit for

subsequent connections. If the unit is not autobauded, the default interface

rate is 38,400 bps.

5.2 Hayes Compatible Commands

All Hayes compatible commands that are used with the Modem are listed

in Table 5-1 (near the end of the chapter). More detailed information is

provided below for selected Hayes commands—particularly those used to

answer and originate calls, and other commonly used commands. For Hayes

commands that control modem options, additional information on options

may be found in Chapter 3. Commands are listed in alphabetical order in

this section and in Table 5-1.

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5.0 Hayes Emulation Mode

For most commands, there are parameters—numerical values used with

the command specifying the function of the command. For example, the

command L controls the modem’s speaker volume. L2 sets the volume to

medium. The default value is a predetermined value which is in effect the

first time the Modem is powered up or when a reset command is given.

The possible parameters and default value for each command are shown

in Table 5-1.

• A — Quick Answer. The A command immediately puts the modem

into the answer mode. The modem will not execute any command

entered in the command line after A.

The A command is used to transfer a call between two individuals to a

communication between their computers: One person enters A while

the other enters D.

• A/ — Repeat Previous Command. A/ is most commonly used to redial

a busy telephone number. The AT prefix is not used with A/, and no

carriage return is required. Commands are available for repetition in the

command buffer only until AT is entered or power to the unit is turned

off. A/ will not work following an AT or after the power has been turned

off and back on.

• D — Originate Mode For Dialing. The modem dials the number that

follows and attempts to go on-line. The dial command D is followed by

either a telephone number to be dialed, or a string consisting of a phone

number and dial command modifiers (e.g., T, P, and ; ). An example of

the D command is shown below:

AT D3331234.

In response to the command above, the Modem dials the telephone

number 333-1234, and then waits for a carrier tone from the remote

modem (default wait time is 30 seconds). If the modem is able to establish

a call, it gives a CONNECT result code, indicating that it is on-line. If it

cannot connect, it issues a different result code, such as NO CARRIER,

BUSY, or NO DIALTONE. The characters that can be dialed are 0

through 9, A, B, C, D, #, and *.

• AT D — the dial command without a telephone number causes the

modem to pick up the telephone line without dialing a number.

• DS —Dial Stored Number. The DS command instructs the Modem to

dial a telephone number or dial string previously stored using the &Z

command. The syntax is DS=m, with m specifying the memory location

where the dialed number will be stored. Up to ten numbers may be stored

in memory locations 0-9. S=m may be placed anywhere in the dial string;

for example, AT D2345S=2 dials 2345 and the number is stored in

memory location 2.

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Modem 34336

• H — Telephone Switch Hook. The H command (on-hook) is used to

terminate a call. (On-hook corresponds to off-line.) H may also alternate

between voice and data transmission during the same call (if your

communication software supports this capability).

The H1 command (off-hook) activates the telephone line relay, causing

a dial tone to be sent after a 2-second delay. For most purposes the

command is not necessary, since the switch hook is automatically

activated when the Modem originates or answers a call.

• L — Link. The L dial modifier is used to link one phone number to

another. One number can be an alternate number to be dialed if a

connection is not made to the primary number. The L parameter must

be used after a phone number, and before a carriage return or period.

A number is used after L to specify the memory address (0-9) containing

the number to be linked to the first number. See the command below.

AT D 555-1212 L5

NOTE

L may also be used in V.25 bis mode with the CRN command (instead of

AT D), in both Dumb mode and 208 operation. In Dumb mode or 208

operation, L is stored via the PHONE screen. In all cases, L is used in

the same way and has the same function as described above (except that

AT D is not used).

Two or more addresses may be linked in a cyclic fashion to alternate

dialing until a connection is established:

Contents of cell 0: 555-1212 L1

Contents of cell 1: 444-1234 L2

Contents of cell 2: 888-5555 L0

With the cells loaded as shown above, if the command AT DS=0 is issued,

the autodialer goes to cell 0 and dials the number stored there. If unable

to connect, the L1 command stored in cell 0 directs the autodialer to dial

the number in cell 1. The L2 stored in cell 1 directs the autodialer to cell

2 (assuming a connection cannot be made), and the L0 command stored

in cell 2 directs the autodialer back to cell 0. The numbers are dialed in

a loop until a connection is established or until 10 calls are attempted.

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5.0 Hayes Emulation Mode

• O — Forced On-Line. For asynchronous operation only. When the

modem is on-line, you can return to the command state by entering

the escape code (+++). After the desired command is executed, use the

O command to force the modem from the command state to the on-line

state.

• P — Pulse Dial. The P command instructs the modem to pulse dial. It

can be entered anywhere in the dialing string: AT P5551212; or it can

be entered alone, followed by a carriage return, AT P, in which case all

subsequent telephone numbers are pulse dialed. If the dial command

does not specify which dialing mode to use, the modem defaults to the

last mode specified.

• S= - Modify S Register. This command is used to write information to

a specified S register. The syntax is Sr=n, where r is the number of the

AT S7=30

This command would change the value of register S7 to 30. If you enter

just =5, the auto-dialer changes the value of the last register used to 5.

More information on S registers is included in Section 5.3.

• S? — Read S Register. This command instructs the autodialer to read

the contents of the specified S register. The syntax is Sr?, where r specifies

the register to be read. For example, S7? reads the value of register S7.

The value is displayed on the computer or terminal monitor. If you enter

? by itself, the autodialer displays the value of the last register used; if =

is entered by itself, the autodialer displays the number of the last register

used (e.g., S2). For information on how to interpret S register values,

see Table 5-3.

• T — Tone Dialing. This command causes a telephone number in the dial

command string to be dialed using tone signals. (See the P command

above for additional information.)

• W — Wait For Dial Tone. The W command (or colon) is used in a dial

string to instruct the Modem to wait for a dial tone before proceeding.

Adjust the wait time (default, 30 seconds) by changing the value in

Modem hangs up and gives a NO DIALTONE result code (if the result

code is enabled by the X command).

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Modem 34336

• Z —Recall Stored User Profile. The Z command resets the modem and

recalls a profile of the modem configuration settings previously saved

using the &W command. The profile is designated as profile 0 or

profile 1 when it is saved using the &W command.

• , —Pause. A comma causes the modem to pause for 2 seconds (or time

specified in register S8) before processing the next character in a dial

string or command. The Pause command is used to place an outside call

through a PBX switchboard, where 9 must be dialed to gain outside

access—the pause allows time for the dial tone to occur before the

modem dials the number:

AT D9,3331234

Similarly, a comma may be used to cause the Modem to wait for a second

dial tone before beginning to dial a telephone number. Use multiple

commas to increase the pause time.

• ; — Forced Command State. A semicolon placed at the end of a dial

command causes the Modem to return to the command state after

dialing without disconnecting.

The following examples illustrate how the ; command is used:

The first example is a banking transaction. The command AT D333-1234;

dials the bank’s phone number and returns the Modem to the command

state. After the OK prompt is displayed on the DTE, the command AT D

T 0901# is entered. The command transmits the identification number

0901 to the bank, and again returns the Modem to the command state.

An account number and other data may be transmitted in the same way.

The second example illustrates one method of autodialing. Enter a dial

string that ends with a semicolon—for example, AT DT9, 3331234;

During the ring signal or when the call is answered, pick up the phone

and enter AT H. You may then use a telephone connected to the Modem

for voice communication.

• Wait For Silence Before Dialing. The @ command is used to gain access

to a system without a dial tone. It tells the modem to wait for 30 seconds

(or the time specified by register S7) for one or more rings followed by 5

seconds of silence before processing the next symbol in the dial string.

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5.0 Hayes Emulation Mode

• ! — Initiate Flash. The ! command causes the Modem to go on-hook for

1/2 second. The command has the same effect as holding the switch-hook

button on your telephone down for 1/2 second. Some PBX systems use a

flash to transfer calls.

• &F — Recall Factory Configuration. The &F command restores the

Modem to its original factory configuration, using data stored in ROM.

However, the change is not permanent. If the Modem is turned off or

reset, the recalled configuration is replaced with the default stored

profile. (See &Y command.)

• &V — View Active Configuration, etc. This command displays the active

modem configuration, user profiles stored using the &W command, and

phone numbers stored using the &Z command. When &V is invoked,

the DTE displays the configuration commands last issued, including

parameters used, and the values currently stored in the S registers. The

&V command should be issued as the last command on a line.

• &W — Write Profile To Memory. The &W command saves the

storable parameters of the Modem’s active configuration by writing the

configuration profile to non-volatile memory. By selecting either &W0 or

&W1, two different user profiles can be saved (profile 0 or 1). One

of these profiles is automatically restored whenever the modem

is powered on or when the Z command is issued. (See &Y and Z

commands.)

The &W command cannot be used to write changes to the user profiles if

the Modem’s front panel is disabled with the Front Panel Control option.

The parameters listed below cannot be stored—all are set by changing S

Backspace character (ASCII 08)

Carrier-detect response time

Carriage-return character (ASCII 13)

DTMF tone duration

DTR detection

Escape-sequence character (ASCII 43)

Escape-sequence guard time

Line-feed character (ASCII 10)

Lost-carrier-until-hangup time

Pause duration (effected by comma)

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Modem 34336

Ring count

Wait time before blind dialing

Wait time for carrier/dial tone

In addition, the &W command does not save stored phone numbers.

• &Z — Store Telephone Number. The &Z command is used to store a

telephone number dialed using the DS (dial stored number) command.

The syntax is &Zm=n, where m specifies the memory location in which

the phone number or dial string is stored and n is the number or dial

string to be stored. For example, AT &Z5=T 1 (301) 555-1212 stores

the specified number at memory location 5. Ten memory locations are

available—0-9.

For pulse dialing, digits 0 through 9 can be stored. For tone dialing,

0 through 9, A through D, #, and * can be stored. The dial-command

modifiers listed in Section 5.1.2 can also be stored.

Each memory cell can hold a maximum of 25 digits. Cells 1 through 9

automatically expand to the next empty cell if loaded with more than 25

digits. Even if a stored number is continued to another cell, the maximum

number of characters that can be stored is 36. If more than 36 characters

are included in a dial string, the command is ignored. A cell cannot hold

a number unless it is empty. Only cell 0 can be accessed from the

Modem’s front panel (via the PHONE LCD screen).

• \S — View Status Of V.42-Related Configuration. The \S command

displays the active V.42 error correction configuration, stored V.42

profiles, and certain other data not displayed by the &V command.

5.3 S Registers

The Modem includes 28 registers (S0-S27) that are used to control specific

modem operations in Hayes mode only. Each register holds a value serving

as a specific operating instruction for the modem. Several of the S registers

affect how the previously described commands are executed.

The functions of the registers intended for user access are explained below

and summarized in Table 5-3.

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5.0 Hayes Emulation Mode

5.3.1 READING AND SETTING REGISTERS

Use the S command to read the value of a register or to change its value.

To read the current value of a register, use the command S?, where the

number of the register is specified between the S and the ?—for example, S9?.

The decimal value of the register contents is displayed. You may read multiple

registers. For example, if you wish to read the current value in registers S0

and S7, enter the following command.

AT S0? S7?

A typical response might be 001, 030, OK, meaning the values stored in

registers S0 and S7 are 1 and 30, respectively.

To set or change a parameter, use the command S=, where the number of the

be assigned to the registers) follows the equal sign:

AT S0=5

The above command changes the value stored in S0 to 5.

The S command can also be used without ? or = to point to a register that will

be read from or written to without being specified. To illustrate this, if you

enter the following command, a pointer is set to the address of register S7.

AT S7

As long as no other S command is entered, the register value can be

requested at any time without specifying the number. If you enter AT ? the

modem displays the current value in the S7 register. Similarly, if you enter

AT=8 the modem changes the value in the S7 register to 8.

5.3.2 S REGISTER FUNCTIONS

This section describes the function of each S register. Table 5-3 lists the range

of possible parameters and the default value for each S register.

• S0 — Ring To Answer On. The value in this register determines on what

ring (first, second, third, etc.) the modem answers. Setting S0 to 0

disables auto-answer.

• S1 — Ring Count. Register S1 counts the number of ring signals for each

incoming call. If more than 8 seconds pass since the last ring, S1 is cleared

to zero.

• S2 — Escape-Code Character. The escape code is effective for

asynchronous operation only. Values greater than 127-completely disable

escape code detection and prevent you from issuing a hang-up command.

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Modem 34336

• S3 — Carriage Return. Register S3 is effective for asynchronous operation

only. Normally, the ASCII carriage-return value, 13, is used.

• S4 — Line Feed. This register is effective for asynchronous operation only.

The line-feed character follows the carriage return only when word result

codes are selected (command V1). Line feed can be changed to a null but

cannot be totally disabled.

• S5 — Backspace. This register is effective for asynchronous operation only.

The value in S5 defines the backspace character. Do not use values

between 33 and 126.

• S6 — Blind-Dialing Wait Time. The value in S6 determines how long the

Modem waits after picking up the telephone line (going off-hook) before

beginning to dial. If S6 is set for less than 2 seconds, the modem waits 2

seconds before dialing. If the X2 or X4 command is in effect, dial-tone

detection is enabled and blind dialing is disabled, meaning the value in

S6 has no effect.

• S7 — Carrier/Dial-Tone Wait Time. This register controls two wait times—

wait time for carrier and, if W is included in the dial string, wait time for

dial tone (or wait time for silence if @ is used).

• S8 — Pause Time. Register S8 controls the pause time effected by a

comma in a dial string or other command line.

• S9 — Carrier Detect Response Time. Register S9 determines how long a

carrier tone must be present for the Modem to recognize the tone and

indicate a carrier detect. (The time required for the absence of a carrier

tone to be recognized is fixed at 0.5 seconds.)

• S10 — Loss Of Carrier Delay. The value in register S10 determines the

length of the delay from the occurrence of a loss of carrier until the

Modem hangs up the telephone line. A value of 255 disables the Modem’s

carrier disconnect option (and line-current disconnect option), meaning

the Modem will not hang up in the absence of carrier or line current.

• S11 — Tones. This register sets the spacing of tones used for dialing. The

rate is slowed by increasing the value of S11 to the maximum value, 255.

This register has no effect on pulse dialing, which is fixed at 10 pulses

per second.

• S12 — Guard Time. This register is effective for asynchronous operation

only. The escape guard-time delay is required immediately before and

after entering the escape code; therefore, the three escape-code

characters must be entered within the guard time delay of each other.

The unit for this register is 1/50 second (or 20 ms), meaning the default

value of 50 equals 1 second.

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5.0 Hayes Emulation Mode

If the guard time is zero, timing is not a factor. The three escape

characters can occur with any timing relationship, but they must be

consecutive. Be cautious when assigning small guard times. You may not

be able to enter three characters fast enough, especially if the guard time

is less than the time required to transmit one character at the current

transmission rate.

• S18 — Diagnostic Timer. The value in register S18 determines how long

a diagnostic test runs. For example, if S18 is set to 120, the test (activated

by one of the &T commands) runs for 120 seconds. If S18 is set to zero

(the default), the test timer is disabled and the test runs indefinitely. To

terminate a test when the test timer is disabled, use the command &T0,

or reset the modem. Register S18 is set to zero on powerup, or by the

command AT Z or AT S18=0.

• S25 — Delay To DTR. The effect of the value stored in register S25

is dependent on the operating mode, as explained below.

Synchronous mode 1 — Before the Modem examines the state of DTR,

a delay occurs after a call is established. The duration of the delay is the

value specified in S25 (in seconds). This allows the operator time to

disconnect the Modem from an asynchronous data terminal and attach

it to a synchronous terminal without forcing the Modem back into the

command state.

Asynchronous mode and synchronous modes 1 and 3 — A change in DTR

(ON or OFF) lasting for less than the value in register S25 (in hundredths

of a second) is ignored by the Modem.

• S26 — RTS To CTS Delay Interval. This register affects synchronous

operation only. With the command &R0 in effect, CTS is turned on in

response to an OFF-to-ON transition of RTS from the local DTE—after

the delay specified by the value in register S26, but only if the Modem is

on-line and ready to receive synchronous data.

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Modem 34336

5.4 Selecting Options In Hayes Mode

In Hayes mode, options may be selected by using one of the following:

• AT commands (Table 5-1)

• The front panel

• The Summary Setup feature

The easiest way to change options in Hayes mode is to use the AT commands

listed in Table 5-1 or the Modem’s front panel.

The following guidelines apply to option selection in Hayes mode:

• If an option is changed using an AT command, the change is effective

for Hayes mode only, unless option changes are saved to memory.

If you change an option using an AT command, and then switch to a

different mode without saving the change, the front panel display LCD

remains unaffected.

• The effect of option changes made using the Summary Setup feature

depends on which user profile (0 or 1) is active. See Section 5.4.1.

5.4.1 SAVING OPTION SELECTIONS

Changes made to option settings cease to be effective if power is removed

from the Modem or if a factory reset occurs—unless the Modem's

configuration is saved to nonvolatile memory. The storable parameters of

the Modem’s configuration can be saved to user profile 0 or 1 using the &W

command (&W0 or &W1). Upon powerup, the Modem recalls either profile

0 or profile 1, depending on which is designated as the default profile.

(The &Y command is used to designate the default profile.) The Modem

is shipped from the factory with profile 0 as the default profile.

As explained in the following sections, the Modem is programmed to treat

profile 0 and profile 1 differently. It is recommended that you use profile

0 for your standard configuration and make it the default profile (&Y0).

Profile 1 is intended for storing an alternate configuration if you need one

(e.g., an alternate application). To view the contents of the user profiles,

use the &V and \S commands.

5.4.2 PROFILE

AND PROFILE

User Profile 0 is linked to the Modem’s front panel (i.e., selections made

using the front panel LCD).

• If you make option changes using the front panel, the option changes for

which there are associated Hayes commands are saved to profile 0 when

you exit the SETUP menu.

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5.0 Hayes Emulation Mode

• If profile 0 is recalled as the active configuration, the LCD screens reflect

the profile 0 configuration.

• If profile 0 is changed by means of Hayes commands or via the Summary

Setup feature and then saved, the changes made are reflected on the

LCD and are effective for all modes.

If you make option changes from the front panel without exiting the SETUP

menu, and then make option changes using Hayes commands and use the

&W command to save them to profile 0, the changes saved to profile 0

override the front-panel selections.

User Profile 1 is not linked to the front panel.

• Option changes made from the front panel are not saved to profile 1.

(Profile 1 can be changed only by using Hayes commands or the

Summary Setup feature.)

• If profile 1 is recalled as the active configuration, the LCD screens are not

affected. When profile 1 is active, it is possible for the LCD to display an

option setting not reflecting the setting currently in effect.

• If profile 1 is changed by means of Hayes commands or via the Summary

Setup feature, the changes are not reflected on the LCD and only affect

Hayes mode operation.

If profile 1 is being used as the active configuration, the options marked

with an asterisk (*) in Table 5-1 should be controlled either with the AT

commands listed in Table 5-1 or using the Summary Setup feature described

in Appendix C. When Profile 1 is active, these options can be changed via

the front-panel LCD, but the changes are effective only for Hayes mode

operation. However, if Profile 0 is subsequently recalled as the active

configuration, the changes are effective at that time.

5.5 Hayes Mode Reference Tables

Table 5-1 lists the Hayes compatible commands used with the Modem.

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Modem 34336

Table 5-1. Hayes Compatible Commands.

COMMAND

FUNCTION/EXPLANATION

Quick Answer

No parameters.

Repeat Previous Command

No parameters.

Bell/CCITT Compatibility Mode *

Selects CCITT V.22 mode.

Selects Bell 212A mode.

Modem displays OK; command has no other effect.

This response instead of ERROR maintains a

degree of compatibility with older modems

supporting this command.

Originate Mode For Dialing

No parameters.

Dial Stored Number

Parameters are 0-9 (available memory locations).

Echo

No echo.

Echoes all characters back to terminal screen when

using a full-duplex terminal and in local command

mode.

Modem displays OK. Command has no other effect

unless V.22 bis/V.22/ V.21/V.23 fallback operation

is enabled.

Telephone Switch Hook

On-hook (hang up).

Off-hook.

H1 or H2

Default settings (where applicable) are in bold face.

* If user profile 1 is active, options are controlled (for Hayes mode

operation) by given commands or Summary Setup. Do not change via

front panel (except via Summary Setup).

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5.0 Hayes Emulation Mode

Table 5-1 (continued). Hayes Compatible Commands.

COMMAND

FUNCTION/EXPLANATION

Product Code Or Checksum

Requests product code.

Requests checksum for the Modem’s software. (Only a

portion of the checksum displayed via the front panel is

displayed in decimal format.)

Requests verification of software checksum.

Requests the following for each EPROM

(programmable memory unit): chip, part and revision

number; checksum.

Reserved.

Link Dial (L specifies LINK function when used as a

dial command modifier.)

Speaker Volume *

Low speaker volume.

Medium volume.

High volume.

L0 or L1

Speaker Control *

Speaker always OFF.

Speaker ON until carrier is detected.

Speaker always ON.

Speaker OFF during dialing; otherwise ON until carrier

is detected.

Forced On-Line

Forces Modem to on-line state.

Forces Modem to on-line state and initiates equalizer

retrain.

Pulse Dial No parameters, but the default is T (for

tone dial).

Send Result Code

Send result codes.

Withhold result codes (quiet).

Withhold result codes for incoming calls only (quiet

answer).

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Modem 34336

Table 5-1 (continued). Hayes Compatible Commands.

COMMAND

FUNCTION/EXPLANATION

Modify S Register

Parameters are register and value to be written.

Read S Register

Parameter is the register number.

Tone Dialing

No parameters.

Word/Digit Result Code

Result codes are transmitted as digits.

Result codes are transmitted as words.

Wait For Dial Tone

No parameters, but default wait time (register S7) is

30 seconds.

Select Result Code

Selects basic result codes, 0-4. No speed indication;

no busy or dial tone detect.

Selects result codes 0-5, 10, 11, 13, 14, 15, and 18.

Connection speed (up to 14,400 bps) indicated; no

busy or dial tone detect.

Selects result codes 0-6, 10, 11, 13, 14, 15, and 18.

Same as X1 except dial tone detect is enabled.

Selects result codes 0-5, 7, 10, 11, 13, 14, 15, and 18.

Same as X1 except busy-signal detect is enabled.

Selects all result codes. Connection speed (up to

14,400 bps) indicated; busy-signal and dial-tone detect

enabled.

Note: Result code 8 is independent of the X command;

it is displayed only when the @ dial modifier is used.

Default settings (where applicable) are in bold face.

* If user profile 1 is active, options are controlled (for Hayes mode

operation) by given commands or Summary Setup. Do not change via

front panel (except via Summary Setup).

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5.0 Hayes Emulation Mode

Table 5-1 (continued). Hayes Compatible Commands.

COMMAND

FUNCTION/EXPLANATION

Long-Space Disconnect*

Disables long-space disconnect.

Enables long-space disconnect.

Recall Stored User Profile

Resets modem and recalls stored user profile 0.

Resets modem and recalls stored user profile 1.

, (comma)

; (semicolon)

Pause –– No parameters, but default pause time (in

Forced Command State

No parameters.

Wait For Silence Before Dialing –– No parameters, but

default wait time (register S7) is 30 seconds.

! (exclamation) Initiate Flash

No parameters

Data Carrier Detect Control *

&C0

&C1

&C2

DCD always ON when DTR is present.

DCD ON only in the presence of suitable data.

DCD ON when DTR is present; then toggles off for

50 ms upon disconnect.

&D0

&D2

Data Terminal Ready Control *

Ignore DTR.

Go on-hook, assume command state and disable auto-

answer upon DTR ON-to-OFF.

Reinitialize in the event of DTR ON-to-OFF.

&D3

Recall Factory Configuration

No parameters.

Guard Tone Control *

&G0

&G1

&G2

Guard tone disabled.

Enables 550 Hz guard tone.

Enables 1800 Hz guard tone.

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Modem 34336

Table 5-1 (continued). Hayes Compatible Commands.

COMMAND

FUNCTION/EXPLANATION

Modem displays OK result code; command has no

other effect. (The Modem is configured for A/A1

control or MI/MIC control via jumpers JP2 and JP3, as

detailed in Appendix D.)

Modem displays OK result code; command has no

other effect. (The Modem is configured for leased line

or dialup line operation via the front-panel QUICK

SETUP and/or LINE TYPE screens.)

Can be substituted for &Q.

Modem displays OK result code; command has no

other effect. (The pulse-dialing ratio is factory-set,

depending on whether the modem is a U.S. or

international model.)

&Q0

&Q1

Asynchronous/Synchronous Mode

Asynchronous mode.

Synchronous mode 1— Synchronous/asynchronous

mode

Synchronous mode 2—OFF-to-ON DTR causes

Modem to automatically dial a stored number.

&Q2

RTS And CTS Options *

&R0

&R1

&R2

CTS follows RTS.

CTS follows DTR from the DTE.

CTS is on while the modem is on-line.

Data Set Ready Control *

&S0

&S1

&S2

DSR always on.

DSR operates according to RS-232 specification.

Options DSR operation for a crossover connection.

Default settings (where applicable) are in bold face.

* If user profile 1 is active, options are controlled (for Hayes mode

operation) by given commands or Summary Setup. Do not change via

front panel (except via Summary Setup).

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5.0 Hayes Emulation Mode

Table 5-1 (continued). Hayes Compatible Commands.

COMMAND

FUNCTION/EXPLANATION

Test Commands

&T0

Terminates a test in progress. &T0 must be the last

command in a command line.

&T1

&T3

&T4

Initiates a local analog loopback test.

Initiates a local digital loopback test.

Allows the local modem to accept a request from the

remote modem for a remote digital loopback test.

Prevents the Modem from accepting a request from the

remote modem for a remote digital loopback test.

Initiates a remote digital loopback test.

Initiates a remote digital loopback test self-test.

Initiates a local analog loopback self-test.

&T5

&T6

&T7

&T8

View Active Configuration, etc.

&V0

Displays modem configuration, user profiles and phone

numbers stored in memory cells 0-5.

Displays all stored phone numbers (contents of memory

cells 0-9).

&V1

Write Profile To Memory

Saves storable configuration parameters as

user profile 0.

Saves storable configuration parameters as

user profile 1.

&W0

&W1

Transmitter Clocking *

&X0

&X1

&X2

Selects internal clocking.

Selects external clocking.

Selects receive mode (slaved) clocking.

&Y0

&Y1

Default User Profile

Stored user profile 0 will be recalled on powerup.

Stored user profile 1 will be recalled on powerup.

Default settings (where applicable) are in bold face.

* If user profile 1 is active, options are controlled (for Hayes mode

operation) by given commands or Summary Setup. Do not change via

front panel (except via Summary Setup).

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Modem 34336

Table 5-1 (continued). Hayes Compatible Commands.

COMMAND

FUNCTION/EXPLANATION

Store Telephone Number

Parameters are 0-9 (available memory locations).

\B0

\B1

Buffer Mode/Speed Conversion * ¹

Disables speed conversion.

Enables speed conversion. <$!B10>

MNP Class (Limit) * ¹

\C1

\C2

\C3

\C4

\C5

Limits operation to MNP class 1.

Limits operation to MNP classes 1 and 2

Limits operation to MNP classes 1 through 3.

Limits operation to MNP classes 1 through 4.

Limits operation to MNP classes 1 through 5.

\D0

\D1

Dialing Message

Disables DIALING message.

Enables DIALING message.

\F0

\F1

MNP Flyback Buffer * ¹

Enables flyback buffer.

Disables flyback buffer.

V.42 Break Handling * ¹

\K0

\K1

\K2

\K3

Selects normal break handling.

Selects destructive/expedited break handling.

Selects non-destructive/expedited break handling.

Selects non-destructive/ non-expedited break handling.

V.42 bis Operation *¹

\M0

Enables V.42 bis operation (error correction with data

compression).

\M1

Disables V.42 bis operation.

¹Option can be changed only when Modem is off-line.

Default settings (where applicable) are in bold face.

* If user profile 1 is active, options are controlled (for Hayes mode operation) by given

commands or Summary Setup. Do not change via front panel (except via

Summary Setup).

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5.0 Hayes Emulation Mode

Table 5-1(continued). Hayes Compatible Commands.

COMMAND

FUNCTION/EXPLANATION

V.42 Mode * ¹

\N0

\N1

\N2

\N3

Disables error correction.

Enables mandatory mode for error correction.

Disables error correction.

Enables automatic mode for error correction.

V.42 Protocol * ¹

\P0

\P1

\P2

Selects LAPM protocol only.

Selects MNP protocol only.

Selects LAPM/MNP protocol (MNP as alternate).

V.42 Flow Control * ¹Two parameters may be used

(e.g., \Q0,1; \Q3,2 , etc.). First parameter specifies DCE-

DTE flow; second (optional) specifies DTE-DCE flow control.

None (no flow control).

CTS on/off or RTS on/off (CTS for DCE-DTE flow

control, RTS for DTE-DCE).

DC1/DC2 flow control.

DC1/DC3 flow control (default for DCE-DTE and

DTE-DCE).

View Status Of V.42-Related Configuration

No parameters.

Load Inactivity Timer

\T0

\Tn

Disables inactivity timer.

Sets inactivity timer to n minutes (where n = 0 to 60).

V.42 Result Codes¹

\V0

\V1

Activates regular V.42 result codes.

Activates extended V.42 result codes.

\X0

\X1

V.42 Pass-Through Flow Control * ¹

Enables pass-through flow control.

Disables pass-through flow control.

NOTE: DTE speed and parity are set automatically. Auto-answer is enabled or disabled by S register S0.

¹Option can be changed only when Modem is off-line.Default settings (where applicable) are in bold face.

* If user profile 1 is active, options are controlled (for Hayes mode operation) by given commands or

Summary Setup. Do not change via front panel (except via Summary Setup).

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Modem 34336

Table 5-2. Hayes Mode Result Codes.

DIGIT

CODE

WORD

CODE MEANING

Command line executed without errors.

CONNECT

Carrier detected at 0-300, 1200, or

2400 bps (basic code set).

RING

Ringing signal detected (in answer mode).

(When the Modem detects a ring, it

sends a RING result code unless it is in

the process of accepting a command.

However, the Modem answers the call

only if it is set for automatic answer or is

given an A command.)

NO CARRIER

ERROR

Carrier lost or never detected.

Error in command line, invalid command,

command line exceeds 40 characters, or

invalid character format.

CONNECT 1200 Carrier detected at 1200 bps.

NO DIALTONE

BUSY

No dial tone detected.

Busy signal detected.

NO ANSWER

No period of silence detected. This code

appears only if @ (wait for silence before

dialing) is included in the dial string.

CONNECT 2400 Carrier detected at 2400 bps.

CONNECT 1275 Modem is on-line in V.23 mode

(1200/75 bps).

CONNECT 12.0 Carrier detected at 12,000 bps.

CONNECT 14.4 Carrier detected at 14,400 bps.

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5.0 Hayes Emulation Mode

Table 5-2 (continued). Hayes Mode Result Codes.

DIGIT

CODE

WORD

CODE MEANING

CONNECT 4800 Carrier detected at 4800 bps.

CONNECT 9600 Carrier detected at 9600 bps.

LINKING

Modem is dialing numbers that are

linked using the L (link) dial modifier.

Note: Four additional word codes are BUFFER, MNP, V42, and V42 bis,

followed by the DTE interface speed. These codes indicate if the Modem is

in buffer, MNP or LAPM (V.42/V.42 bis) mode. The corresponding digit

codes and speeds they indicate are listed below (with all speeds in bits per

second):

BUFFER:

MNP:

28=19200, 29=9600, 30=4800, 31=2400, 32=1200,

33=600, 34=300, 35 -110, 53=38400

36=19200, 37=9600, 38=4800, 39=2400, 40=1200,

41=600, 42=300, 43 -110, 54=38400

44=19200, 45=9600, 46=4800, 47=2400, 48 -1200,

49=600, 50=300, 51=110, 52=38400

55=38400, 56=19200, 57=9600, 58=4800, 59=2400,

60=1200, 61=600, 62=300, 63=110

V42:

V42 bis:

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Modem 34336

Table 5-3. S Register Functions.

(Only registers intended for user access are listed.)

DEFAULT DESCRIPTION

0-255

0-127

2-255

rings

ASCII

sec

Ring to answer on

Counts number of rings

Escape-code character

Carriage-return character

Line-feed character

Backspace character

Wait time before blind

dialing

1-60

sec

Wait time for carrier or

dial tone

0-255

1-255

sec

Pause time for comma

1/10 sec

Carrier-detect response

time

S10

1-255

1/10 sec

Delay time between loss

of carrier and hang-up

S11

S12

S18

S25

70-255

0-255

Tone spacing

1/50 sec

sec

Escape code guard time

Test timer

sec or

1/100 sec

Delay to DTR¹

S26

0-255

1/100 sec

RTS-to-CTS delay (half

duplex)

¹Depends on mode; see previous section, S25 - DELAY TO DTR.

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6.0 V.25 bis Autodialer

For international compatibility, the Modem can function as a V.25 bis

autodialer. In V.25 bis mode, the Modem is compliant with CCITT

recommendation V.25 bis—an internationally recognized standard for serial

automatic call origination and answering.

The V.25 bis autodialer uses the dialing command set defined by the V.25 bis

recommendation. You can store and dial phone numbers from the DTE in

both synchronous and asynchronous applications. You can dial numbers

directly, or you can instruct the Modem to automatically dial a previously

stored number.

6.1 Enabling The V.25 bis Autodialer

The V.25 bis autodialer can be enabled by either using the Quick Setup

feature, or selecting one of the Dialer Mode options.

QUICK SETUP

Three Quick Setup configurations are available for 2-Wire Dial (V.25 bis).

Selecting any of the three V.25 bis Quick Setups (via QUICK on SETUP

screen 1) enables the V.25 bis autodialer and causes all modem options to be

automatically set to a preset configuration. Each V.25 bis Quick Setup is

suitable for a typical V.25 bis application, depending on the DTE to be used.

To select a 2-Wire Dial (V.25 bis) Quick Setup, access QUICK SETUP screen

2, 3, or 4 (for asynchronous; synchronous, character-oriented; or synchro-

nous, bit-oriented operation) on the LCD, and then press push-button 2.

After selecting the desired V.25 bis Quick Setup configuration, you can reset

individual options to suit your application (see Chapter 2).

In accordance with the CCITT V.25 bis recommendation, the Modem V.25 bis

asynchronous Quick Setup sets the character length to 10 bits, including 1

even parity bit. Both V.25 bis synchronous Quick Setups set the modem for

odd parity. (For synchronous operation, the character length option setting

has no effect.)

DIALER MODE (DIAL V25BIS SCREEN)

If you enable the V.25 bis autodialer using the Dialer Mode option, no other

options are changed. Select DIALER from SETUP screen 2. Then, press the

right arrow pushbutton to go to the DIAL V25 bis screen (screen 2). Select

the V.25 bis data protocol appropriate for the DTE to be used: asynchronous

(Asyn); synchronous, character-oriented (Syn_c); or synchronous, bit-

oriented (Syn_b).

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Modem 34336

DTR DIALING IN V.25 BIS MODE

An alternative to using the V.25bis CRS command to dial a stored number is

to use the DTR dialing option. With DTR dialing enabled, the autodialer will

dial the number stored in the phone cell displayed in the front-panel AUTO-

DIAL screen when DTR goes high for at least 50 ms.

To enable V.25 bis DTR dialing, sue the Summary Setup feature (see

Appendix C) to change the parameter for V25 bis DTR dialing to 1. Do not

select DTR dialing via the front panel DIALER screen; this will not enable

DTR dialing for V.25 bis mode. V.25 bis DTR dialing will function only if

the V25bis DTR dialing parameter is enabled (set to 1) and the V.25 bis

autodialer is enabled.

6.2 V.25 bis Autodialer Commands

In asynchronous applications, V.25 bis commands are issued directly from

the DTE keyboard or through communications software. In synchronous

applications, the V.25 bis commands are used to facilitate computer-

controlled communications.

Punctuation and spaces may be used with V.25 bis commands for clarity,

but they are not required. If used, they are ignored by the modem. One

exception is the colon ( : ), which instructs the autodialer to wait for a

dial tone.

The V.25 bis commands are described below and are summarized

in Table 6-1. See Table 6-3 for explanation of the codes displayed

in response to commands.

• CIC — Connect Incoming Call. The CIC command instructs the

autodialer to answer incoming calls. The effect is the same as enabling

auto-answer on the modem’s front panel.

• CRN — Call Request, Number Provided (Syntax: CRN 5557979). By

using the CRN command, you can dial a number directly from the DTE

keyboard. Numbers from 0 through 9 can be dialed, and if tone dialing

is enabled, the characters A, B, C, D, #, and * can also be dialed.

The dialing parameters listed in Table 6-2 are used with the CRN

command to specify how or when a number should be dialed. For

example, the command line CRN :T3331234 instructs the autodialer

to wait for a dial tone (:) and then tone-dial (T) the number 333-1234.

• CRS — Call Request, Address Provided (Syntax: CRS 2). The CRS

command allows you to dial a number simply by specifying its memory

address. In the example given above, the autodialer dials the number

stored in memory address 2. Store the number at the specified address

using the PRN command (Table 6-1).

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6.0 V.25 bis Autodialer

• DIC — Disregard Incoming Call. The DIC command instructs the

autodialer not to answer an incoming call. The DIC command is

cancelled when the CIC command is issued or auto-answer is enabled

from the front panel.

• PRN — Program Normal (Store Number)

(Syntax: PRN<|>1;<|>5551212). The PRN command is used to store

a number or dial string in a memory address location (cell) so it can

be dialed later by specifying only the address. As shown above, PRN is

followed by the memory location, a semicolon, and the phone number

to be stored. After a number is stored, it can be dialed using the CRS

command. You can store any of the characters listed in Table 6-2.

Ten memory cells (0-9) are available for phone number storage. Each

cell can hold a maximum of 25 characters, although cells 1 through 9

automatically expand to the next empty cell if loaded with more than 25

digits. Even if a stored number is continued to another cell, the maximum

number of characters that can be stored is 36. You cannot store a number

in a cell unless it is empty. To clear a cell, enter PRN and the address,

without a number. Only cell 0 can be accessed from the modem’s front

panel (via the PHONE LCD screen).

• RLN -— Request Stored Number(s). RLN is used to request a list of

all stored numbers or to show the number stored in a specific memory

address. RLN, used alone, requests a list of all stored numbers.

The DTE display shows the stored numbers as follows:

LSN 0;

LSN 1;

LSN 2;

301 555 1234

301 123 4567

301 555 5555

(and so on through memory address 9)

If a memory address is specified after RLN, e.g., RLN 5, the DTE display

shows only the number stored at the specified address.

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Modem 34336

Table 6-1. V.25 bis Autodialer Commands.

FUNCTION

COMMAND

CIC

Connect incoming call.

CRN n

Call request—dial number (n) entered on DTE

keyboard.

CRS m

Call request—dial number stored in specified

memory address (m).

DIC

Disregard incoming call.

PRN m n

Program normal—store number or dial string n in

memory address m.

RHA

Switch to Hayes dialing mode (also resets modem

configuration).

RLN

Request list of all stored numbers.

RLN m

Request to see number stored at address m.

n — represents a number to be dialed or stored (e.g., 5557979).

m — represents a memory address where a number is stored (0-9).

A comma ( , ) can be included in a dial string to effect a pause.

A colon ( : ) can be included to instruct the autodialer to wait for a dial tone

before proceeding.

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6.0 V.25 bis Autodialer

Table 6-2. V.25 bis Dialing Parameters.

(Table also applies to Dumb mode and Bell 208 operation)

Characters that can be dialed: 0—9

Can only be tone dialed:

A, B, C, D, #, and *

Links a phone number to another

number to be dialed as an alternate

when the primary number is busy or

does not answer. See L - LINK in

Section 5.2.

Sets pulse-dialing mode.

Sets tone-dialing mode.

W or : (colon)

Wait 30 seconds for dial tone before

proceeding.

[CR] or .

(carriage return

or period)

Required at end of dial command line.

[CR] is sent from DTE keyboard.

Dumb/208 mode only: Period has

same function, but may be entered via

front panel (PHONE LCD screen).

, (comma)

or <

Pause before processing next

character in dial string.

L, P, T, and W may be entered as upper- or lower-case letters. Spaces or

hyphens (-) may be used as separators for clarity; they have no effect.

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Modem 34336

6.3 Dialing Parameters

Table 6-2 lists dialing parameters you can use with the CRN command

to modify dialing operations.

6.4 V.25 bis Result Codes

Table 6-3 explains the result codes, or responses, that are displayed

on the DTE monitor during V.25 bis operation.

6.5 DTR Dialing In V.25 bis Mode

An alternative to using the CRS command to dial a stored number is to use

the DTR dialing option. With DTR dialing enabled, the autodialer dials the

number stored in memory address 0 when DTR goes high for at least 50 ms.

To enable V.25 bis DTR dialing, use the Summary Setup feature (as described

in Appendix C) to change the parameter for V.25 bis DTR dialing to 0. Do

not select DTR dialing via the front-panel DIALER screen; it does not enable

DTR dialing for V.25 bis mode.

Table 6-3. V.25 bis Result Codes.

CODE

CFI AB

CFI ET

CFI NS

MEANING

Call failure; absence of carrier.

Call failure because of busy signal.

Call failure; call request specified an address that

does not contain a stored number.

CFI NT

INC

Call failure; no answer tone detected.

Incoming call.

INV

Invalid command entry.

LSN

List of stored numbers; is followed by memory

address, stored number, next memory address, next

stored number, etc.

VAL

Command accepted; waiting for next command.

A semicolon may be used to separate parameters, e.g., LSN 4;5559797.

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7.0 Diagnostics

The troubleshooting information in this chapter applies to all Modem

applications (all dialup and leased line modes), unless specifically stated

otherwise.

For specific test procedures, turn to one of the following sections in this chapter:

• Section 7.7 — Local Modem Diagnostics

• Section 7.8 — Remote Diagnostics

7.1 When And Why To Test

If you experience communications difficulties, you should try to isolate the

defective component in your communications system. You must first identify

the symptoms and scope of the problem. Then, perform a physical inspection

of all units and connections in the system. Finally, conduct diagnostic tests.

Very often the diagnostic testing capabilities of the Modem help identify

the specific faulty component, whether it is the modem, the DTE, or the

telephone line.

7.2 Symptoms and Scope of The Problem

To isolate the problem, carefully consider each of the following questions:

• When did the problem begin?

• What is malfunctioning? Try to isolate the component or components

of your system that are malfunctioning.

• Has there been a recent change in the system?

• Has the modem been reconfigured?

You can quickly find out if the modem is reconfigured by checking the

checksum shown in the SUMMARY screen (accessed via SETUP screen 6)

and comparing it with the checksum displayed when the modem was

operating properly. If the checksum is different from the original, one or

more option settings are changed. If you previously recorded the number

strings (i.e., option parameters) displayed in the setups screens, you can

determine which option settings are changed (by comparing the previous

and current option parameters).

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Modem 34336

7.3 Physical Inspection

The next step in isolating a defective component is inspecting the system.

If you can trace the problem to a specific site, examine that site. Check the

installation of the modem and DTE. Are all cables in good condition and

fully connected? Are all components in the system receiving power? Inspect

the system as thoroughly as possible.

7.4 Overview Of Modem Diagnostics

Once you identify the symptoms and conduct a physical inspection of the sites

in question, you can use diagnostic monitoring and testing to further isolate

the problem. The Modem is equipped with diagnostic capabilities enabling

you to locate faults quickly and easily. The diagnostic features of the Modem

fall into two categories — local and remote — as listed below.There are six

types of local modem diagnostics:

• Analog loopback (ALB)

• Analog loopback self-test (ALBST, or ST)

• Analog loopback self-test with errors (ST/E)

• External analog loopback (ALBX)

• External analog loopback self-test (ALXST)

• Digital loopback (DLB)

There are two types of remote diagnostics:

• Remote digital loopback (RDL)

• Remote digital loopback self-test (RDLST)

The sequence in which you should conduct diagnostic tests depends upon the

symptoms you identified, the availability of personnel at the remote site, and

external test equipment. The self-test pattern generator and pattern detector

built into the Modem alleviate the requirement for external test equipment.

With the non-self tests, use either a standard DTE or an external bit error rate

test (BERT) to generate test data and compare it with received data.

Because more transmission errors occur at higher speeds on marginal

transmission facilities, begin testing at the highest available speed. If errors

occur, reduce the speed and try again. If you cannot correct the problem,

contact your supplier.

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7.0 Diagnostics

7.5 How to Select and Activate Tests

7.5.1 FRONT-PANEL CONTROL

Tests are accessed and activated in the same way options are selected: by using

the LCD and front panel pushbuttons (as explained in Chapter 3). To find

the LCD screen for a specific test, refer to the LCD flow chart (Diagnostic

And Control Functions) at the end of this manual. Once you access the

screen for a specific test, press pushbutton 1 to begin the test (select ON). A

test status screen is automatically displayed. To deactivate a test, press the

ENT pushbutton and then pushbutton 3. (The ENT button cannot be used to

exit the text screen until the test is deactivated.)

NOTE

For valid test results, error correction must be disabled before diagnostic

tests are run. To disable error correction, set the V.42 Mode option to

OFF.

7.5.2 RUNNING TESTS IN HAYES MODE

In Hayes emulation mode only, most of the diagnostic tests available on the

Modem can be activated via the DTE keyboard using the &T commands listed

in Chapter 5. To set the duration of a test, assign a value to register S18. For

example, AT S18=30 sets the test time to 30 seconds. The command &TO

terminates a test. For further information, see Section 5.2.

7.5.3 REMOTE TEST CONTROL

You can configure the Modem to ignore or accept requests from remote

modems to initiate tests on your Modem. To access the remote-test control

option, select TEST from SETUP screen 4. Then, select RMT from the TEST

OPTIONS screen. From the REMOTE TEST screen, select ENABLE to allow

remote test initiation or DISABLE to refuse remote test requests.

7.6 Diagnostic Monitoring: Status Screens

To obtain additional information about the status of the communications

system, observe the status screens described in the following sections. To

view these screens, push the ENT button until the EIA status screen appears.

Use the right arrow pushbutton to advance to other status screens.

7.6.1 EIA STATUS SCREEN

The EIA status screen indicates the

operational status of the modem and

D TR MR RS CS TD

the condition of certain EIA RS-232

leads. The abbreviations that appear

are identified below; however, only

a few of these abbreviations are

9600 TM ER CD RD

displayed during actual operation.

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Modem 34336

D = Dial line occupied

R = Ringing (R appears in same position as D.)

S = Connection secured by security handshake (S appears in same position

as D. S and D may flash alternately.)

TR = Data Terminal Ready

MR = Data Set Ready

RS = Request to Send

CS = Clear to Send

TD = Transmit Data

9600, 4800, etc. = Data speed

(idle—the Modem is off-line—or H-01, H-14, etc., may also be displayed

in the data speed position; see following text.)

TM = Test mode

ER = Error (poor signal quality)

CD = Carrier Detect

RD = Receive Data

When two modems establish a connection, they engage in an exchange

known as a handshake. While a handshake is taking place, the Modem

displays several codes ranging from H-01 to H-28 in the lower left corner

of the EIA status screen. A handshake lasts for up to 12 seconds and is

accompanied by various audible tones.

By pressing pushbutton 1 while the EIA status screen is displayed, you can

access two checksum screens, one for the Modem’s main circuit board and

one for the data pump. The checksums provide data intended for use by

servicing personnel. The checksum screens also show the software revision

levels (which are also shown on the power-on screen).

7.6.2 OTHER STATUS SCREENS

• Quality Screen. Displays the quality of the received signal carrier as

a numeric value and as a horizontal bar graph. A low numeric value

indicates good signal quality. The best possible signal quality is indicated

when the bar graph extends all the way to the right edge of the LCD.

• Line Levels Screen. Shows the preset level of the transmit signal (TX)

and the measured level of the receive signal (RX).

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7.0 Diagnostics

The RX value is the local receive level of the incoming signal. The receive

level range of measurement is from 0 to -43 dBm in 1.5-dBm increments.

If the signal level is less than the carrier detect threshold, "<CD" is

displayed.

• Echo Characteristics Screen. Displays the characteristics of the echo

portion of the receive signal. Specifically, it shows milliseconds of delay

and the offset frequency in Hertz.

• Channel Frequency Offset. Displays the frequency offset of the receive

signal in Hertz.

• Throughput Screen. Functions only if error correction is enabled.

It shows the rate (in bits per second) at which the Modem is accepting

charatcters from the DTE.

• Packet Screen. The packet screen functions only when error correction

is enabled. It has three components, as explained below.

Size. Shows size of data packets (MNP) or blocks (V.42/V.42 bis)

currently being transmitted. MNP uses shorter packets to transmit

through noisy lines and longer packets (allowing greater throughput)

when line conditions are good. The maximum MNP packet size is 64

(MNP classes 1-3) or 256 characters (MNP classes 4 and 5). The block

size for V.42/V.42 bis is fixed at 128 characters.

Transmitted (TX). Number of packets or blocks transmitted since the

connection was established.

Errors (ER). Number of retransmissions (retransmitted because of data

errors) since the connection was established.

• Mode and Rate Screen. Shows the following data:

Mode. Below MODE, the screen indicates the error correction status:

NORMAL — Error correction and buffer mode are both inactive.

V42 — V.42 error correction (LAPM) is active.

V42bis — V.42 bis error correction (LAPM with data compression)

is active.

MNP 01 to MNP 05 — MNP error correction is active.

BUFFER — Buffer mode is active.

OFFLINE — Modem is off-line.

Rate. Shows the data rate of the DTE.

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Modem 34336

7.7 Local Modem Diagnostics

Local modem diagnostics are for testing the Modem and its adjoining system.

The tests are accessed from the main menu and are easily performed if the

Modem is attached to DTE or an external BERT.

7.7.1 ANALOG LOOPBACK (ALB) TEST

Analog loopback testing allows you to test the local modem and its associated

terminal independently from the telephone interface and the remote

modem. Figure 7-1 shows the connections automatically made during the

test.

TRANSMITTER

DATA TERMINAL EQUIPMENT

(DTE) AT LOCAL SITE

RECEIVER

LOCAL MODEM

Figure 7-1. Analog Loopback Test.

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7.0 Diagnostics

In Hayes emulation mode only, initiate the ALB test using the command &T1

(preceded by AT). In any mode, initiate the ALB test using the modem’s

front panel controls, explained in the following paragraphs.

Make sure the modem is idle, the data rate is the same as the DTE’s data rate,

and the DTR circuit is on. (If TR is present on the EIA status screen, the DTR

circuit is on.)

From the second page of the LCD MAIN MENU, select TEST. TEST takes you

to screen 1 of the LOCAL TEST menu, where ALB is displayed as one of the

test selections. Select ALB.

The ANALOG LOOPBACK screen is displayed, with ON and OFF as the

possible selections.

Select ON to activate the test. In general, the "DSR during ALB test option"

discussed in Chapter 3 should be left ON (default selection) to avoid

disrupting the DTE and DTE software operations.

The EIA status screen is displayed while the test is being conducted. Make

sure that test data is being generated. Watch for data errors. By transmitting

test data and comparing it with the received copy, you can make sure the DTE

and modem are both working.

To end the test, press the ENT pushbutton to return to the ANALOG

LOOPBACK screen, and then select OFF.

7.7.2 ANALOG LOOPBACK SELF-TEST (ALBST)

In the analog loopback self test, the modem is placed in analog loopback and

data is sent and received by an internal 511-bit pattern generator and

receiver. Therefore, no DTE or external BERT is necessary. Figure 7-2 shows

the data flow for this test.

In Hayes mode only, initiate the ALBST using the command &T8 (preceded

by AT). In any mode, initiate the ALBST using the modem’s front-panel

controls, as follows:

From page 2 of the LCD MAIN MENU, select TEST. This takes you to screen

1 of the LOCAL TEST menu, where ALBST is visible as one of the selections.

Select ALBST.

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Modem 34336

829 Block

External loopback

(leased line)

Transmitter

Receiver

Pattern

generator

Pattern

detector

Figure 7-2. Analog Loopback Self-Test (ALBST).

The SELFTEST screen is displayed, with ON and OFF as the possible

selections. Select ON to activate the test. The EIA status screen is displayed

while the test is being conducted. If ER is present on the front panel, data

errors occurred. The ER indicator may flash on when the test is first started,

but it should quickly go out and remain off until the end of the test.

To end the test, press the ENT pushbutton to return to the SELFTEST screen.

Then select OFF.

7.7.3 ANALOG LOOPBACK SELF TEST WITH ERRORS (ST/E)

In the analog loopback self test with errors, data is sent and received by an

internal 511-bit pattern generator and receiver. No DTE or external BERT is

necessary. This test differs from the ALBST in that errors are injected into the

data flow every few seconds. The data flow is the same as that shown in Figure

7-2 (the ALBST).

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7.0 Diagnostics

To run the test, go to the LCD MAIN MENU. From page 2 of the LCD MAIN

MENU, select TEST. This takes you to screen 1 of the LOCAL TEST menu,

where ST/E is visible as one of the selections. Select ST/E.

The SELFTEST W/ERROR screen is displayed, with ON and OFF as the

possible selections. Select ON to activate the test. The EIA status screen is

displayed. The ER indicator should flash every few seconds, indicating that

the pattern generator and detector are working. Errors are injected every few

seconds. To end the test, press the ENT pushbutton to return to the

SELFTEST W/ERROR screen. Then select OFF.

7.7.4 EXTERNAL ANALOG LOOPBACK (ALBX) TEST

The external analog loopback test is available forB.

The ALBX test allows you to test the local modem and its associated terminal,

and to verify the availability of the leased-line circuit. The test circuit does not

include the remote modem. Figure 7-3 shows the connections automatically

made during the ALBX test.

829 Block

External loopback

(leased line)

Receiver

Data terminal

Transmitter

equipment (DTE)

at local site

Local modem

Figure 7-3. External Analog Loopback Test (ALBX).

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Modem 34336

NOTE

The ALBX test may result in errors or may fail altogether even where

conditions are satisfactory for normal operation. The test channel

presented to the modem during the ALBX test includes all impairments

of both the inbound and outbound channels (ampli-tude distortion, delay

distor-tion, noise, etc.). The main purpose of the ALBX test is to verify

that the Modem is connected to the leased line and the leased-line circuit

is complete. The test is not meant to assess the suitability of the leased

line.

Initiate the ALBX test using the Modem’s front-panel controls, as explained

in the following paragraphs.

Make sure the local modem is not in communication with the remote

modem, the data rate is the same as the DTE’s data rate, and the DTR circuit

is on. (If TR is present on the EIA status screen, the DTR circuit is on.)

From the second page of the LCD MAIN MENU, select TEST. Go to the

second page of the LOCAL TEST menu. Select ALBX.

The ANALOG LOOP(EXT) screen is displayed, with ON and OFF as the

possible selections.

Select ON to activate the test. In general, the "DSR during ALB test" option

discussed in Chapter 2 should be left ON (default selection) to avoid

disrupting the DTE and DTE software operations.

The EIA status screen is displayed while the test is being conducted. If no

external loopback is present, the status screen displays an IDLE message. If a

loopback is present, handshake sequence codes appear (H-01, etc.), followed

by the modem speed. Ensure that test data is being generated and watch for

data errors. By transmitting test data and comparing it with the received

copy, the DTE and modem are checked for proper operation. During the

ALBX test, RD (receive data) may appear on the status screen even though no

data is being received.

On a flat line, the Modem in ALBX test mode trains and remains running

across the following range of signal loss: in V.32 mode, 0-51 dBm (0-52 dBm

at 12,000 bps); for V.33 operation, 0-47 dBm; and for Bell 208A/B operation,

0-37 dBm. If signal loss exceeds the limits, the test may not start or may be

halted.

During the ALBX test, the modem attempts to retrain upon loss of carrier.

In switched carrier mode, the modem attempts to retrain upon loss of RTS.

To end the test, press the ENT pushbutton to return to the ANALOG

LOOP(EXT) screen. Then select OFF.

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7.0 Diagnostics

7.7.5 EXTERNAL ANALOG LOOPBACK SELF-TEST (ALXST)

The external analog loopback self-test is available for 4-wire leased line mode

only.

The ALXST places the modem in analog loopback and causes data to be sent

and received by an internal 511-bit pattern generator and receiver. No DTE

or external BERT is necessary. As shown in Figure 7-4, the test circuit includes

the leased lines (the external loopback).

NOTE

The ALXST may result in errors or may fail altogether even where

conditions are satisfactory for normal operation. The test channel

presented to the modem during the ALXST includes all impairments of

both the inbound and outbound channels (amplitude distortion, delay

distortion, noise, etc.). The main purpose of the ALXST is to verify that

the modem is connected to the leased-line and the leased line circuit is

complete. The test is not meant to assess the suitability of the leased

line.

TRANSMITTER

RECEIVER

PATTERN

GENERATOR

PATTERN

DETECTOR

Figure 7-4. External Analog Loopback Self Test (ALBST).

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Modem 34336

To initiate the ALXST, use the Modem’s front-panel controls to go to the

LCD MAIN MENU. From page 2 of the LCD MAIN MENU, select TEST.

Go to the second page of the LOCAL TEST menu. Select ALXST.

The ANALOG ST (EXT) screen is displayed, with ON and OFF as the possible

selections. Select ON to activate the test.

The EIA status screen is displayed while the test is being conducted. If no

external loopback is present, the status screen displays an IDLE message.

If a loopback is present, handshake-sequence codes appear, followed by the

modem speed. If "ER" is present on the front panel, data errors occurred.

The ER indicator may flash on when the test is first turned on, but it should

quickly go out and remain off until the end of the test.

The information at the end of the previous section (for the ALBX test)

concerning signal loss, loss of carrier, and loss of RTS also applies to the

ALXST.

To end the test, press the ENT pushbutton to return to the ANALOG ST

(EXT) screen. Then select OFF.

7.7.6 DIGITAL LOOPBACK TEST (DLB)

Digital loopback testing determines the operational performance of the local

modem, the remote modem, and the telephone line as a composite system.

For the test, data must be sent and received at the remote modem. The test

regenerates the data and loops it back to the remote modem. As with the ALB

test, a comparison of the results of the DLB test indicates whether or not the

DTE is performing satisfactorily. A comparison of the results of the ALB and

DLB tests can help determine whether the modem or the telephone line is

defective.

In the DLB test, the data to be sent and received is originated and checked by

the DTE or external BERT. Figure 7-5 shows the data flow for this test.

In Hayes mode only, initiate the DLB test using the command &T3 (preceded

by AT). In any mode, initiate the DLB test using the modem’s front-panel

controls.

From page 2 of the LCD MAIN MENU, select TEST. Go to the second page of

the LOCAL TEST menu. Select DLB.

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7.0 Diagnostics

RECEIVER

TRANSMITTER

LOCAL

REMOTE

MODEM

TRANSMITTER

RECEIVER

DATA TERMINAL EQUIPMENT

(DTE) AT LOCAL SITE

REMOTE MODEM

LOCAL MODEM

Figure 7-5. Digital Loopback Test (DLB).

The DIGITAL LOOPBACK screen is displayed, with ON and OFF as the

possible selections. Select ON to activate the test. The EIA status screen is

displayed while the test is being conducted. Ensure that test data is being

generated and watch for data errors. By transmitting test data and comparing

it with the received copy, the DTE is checked for proper operation. To end

the test, press the ENT pushbutton to return to the DIGITAL LOOPBACK

screen. Then select OFF.

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Modem 34336

7.8 Remote Modem Diagnostics

The Modem performs two tests on compatible remote modems: remote

digital loopback (RDL) and remote digital loopback self test (RDLST).

If a problem is encountered and the local Modem passes all diagnostic tests,

the local Modem can test the remote modem.

Two (noncontiguous) REMOTE TEST screens are on the Modem’s LCD.

The remote tests are initiated from the REMOTE TEST menu. (Select RMT

from MAIN MENU screen 2. Select TEST. Then, select the test type.) A

remote test cannot be initiated unless the Remote Test option is enabled

on the remote modem. This option (also REMOTE TEST on the LCD) is

accessed via SETUP screen 4.

7.8.1 REMOTE DIGITAL LOOPBACK (RDL) TEST

The RDL test (Figure 7-6) allows testing of the local modem, remote modem

and telephone line from the local site.

In Hayes mode only, initiate the RDL test using the command &T6 (preceded

by AT). In any mode, initiate the RDL test from the Modem’s front panel.

Both modems should be on-line and should be tested at the DTE’s data rate.

Ensure that the DTR circuit is on. If TR is present on the EIA status screen,

the DTR circuit is on.

RECEIVER

TRANSMITTER

LOCAL

MODEM

TRANSMITTER

RECEIVER

DATA TERMINAL EQUIPMENT

(DTE) AT LOCAL SITE

REMOTE MODEM

Figure 7-6. Remote Digital Loopback Test (RDL).

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7.0 Diagnostics

From page 2 of the MAIN MENU, select RMT. Then select TEST.

From the REMOTE TEST menu, select RDL.

From the REMOTE DIGIT LOOP screen, select ON to activate the test. The

status screen is displayed as the test is being conducted. Make sure that test

data is being generated and watch for data errors. By transmitting test data

and comparing it with the received copy, you can make sure the Modems

and the telephone line are working.

To end the test, press the ENT pushbutton to return to the REMOTE DIGIT

LOOP screen. Then select OFF.

7.8.2 REMOTE DIGITAL LOOPBACK SELF-TEST (RDLST)

The RDLST allows testing of the local modem, remote modem, and

telephone line from the local site (as did the previous test). However,

test data is generated by internal modem circuitry as opposed to a DTE

or external BERT. Figure 7-7 shows the connections automatically made

during the test.

In Hayes mode only, initate the RDLST using the command &T7 (AT &T7).

In any mode, initate the RDLST test from the front panel.

Both modems must be on-line. From the second page of the MAIN MENU,

select RMT. Then, select TEST. From the REMOTE TEST menu, select

RDLST.

From the RDL SELFTEST screen, select ON to activate the test. The status

screen is displayed as the test is being conducted. If "ER" is present on the

status screen, the modem is detecting errors. If numerous errors are detected,

take steps to try to identify their source.

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Modem 34336

TRANSMITTER

RECEIVER

PATTERN

TRANSMITTER

RECEIVER

GENERATOR

PATTERN

DETECTOR

REMOTE MODEM

LOCAL MODEM

Figure 7-7. Remote Digital Loopback Self Test.

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APPENDIX A: DB25 Pin Assignments

Appendix A: DB25 Pin Assignments

Desig-

LCD

Pin nation Function

Indicator Source

-P

Frame ground—not connected

Transmit data (TD)

DTE

Modem

DTE

Receive data (RD)

Request to send (RTS)

Clear to send (CTS)

Modem

Ground

Modem

DTE

Data set (modem) ready (DSR)

Signal Ground (SG)

Carrier Detect (CD)

Testing voltage, +10V

Testing Voltage - 10V

Transmit Clock (TC)

Receive Clock (RC)

Analog loopback (ALB) control¹

Data terminal ready (DTR)

Remote digital loopback (RDL) control¹

Ring Indicator (RI)

DTE

Modem

DTE

Speed Select (CH/CI)²

External transmist clock

Test mode indicator (TM)³

DTE

Modem

¹+voltage activates indicated loopback test (only if ALB-DTE controled

or RDL-DTE controled option is enabled); -voltage disables test.

²+voltage, 14,400 bps; -voltage, 2400 bps.

³Alternatively, pin 25 may be used for analog loopback (ALB) control.

See Appendix D.

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Modem 34336

Appendix B: Quick Setup Configurations

Table B-1 shows the complete default configuration for each of the Quick

Setup modes. When you select a Quick Setup, the modem automatically sets

all options as indicated in the table. The options are listed in the same order

in which they appear on the LCD flow chart. See 2.0, Quick Start, for

instructions on selecting Quick Setups.

NOTE: All notes appear at the end of the table.

Table B-1. Quick Setup Configurations.

Default Settings Listed by Mode or Type of Operation

V.25 bis

2-WIRE 4-WIRE

BELL

OPTION

HAYES ASYNC¹DUMB LEASED²LEASED²V.33

208³

2W-LL 4W-LL 4W-LL 2W-D

Line Type Line Type

2W-D

19200

300

2W-D

19200

300

2W-D

19200

300

Speed

(Data

Rate)

Speed, Max

Speed, Min

Speed Type

V.42 Mode

19200

4800

V.32

19200

4800

V.32

14400

12000

V.33

4800

208

V.32

Auto

V.32

Auto

V.42

Error

Auto¹

Auto

OFF

Correction MNP Class

Options

(Limit)

V.42 Break

Handling

NDT/

NEXP

NDT/

NEXP

NDT/

NEXP

NDT/

NEXP

NDT/

NEXP

NDT/

NEXP NEXP

V.42

Protocol

LAPM/

MNP

LAPM/ LAPM/

MNP MNP

LAPM/ LAPM/ LAPM/ LAPM/

MNP MNP MNP MNP

V.42 bis

Buffer

Enable

38400

Enable Enable

Enable¹Enable

Enable Enable Enable Enable

Enable Enable Disable Disable

DTE Speed

38400

38400 38400

Flow Control

DTE-DCE

DC1/

DC3

DC1/

DC3

DC1/

DC3

DC1/

DC3

DC1/

DC3

DC1/

DC3

DC1/

DC3

Flow Control

DCE-DTE

DC1/

DC3

DC1/

DC3

DC1/

DC3

DC1/

DC3

DC1/

DC3

DC1/

DC3

DC1/

DC3

DTE Pass-thru

Flow Control

Disable

Disable Disable Disable Disable Disable Disable

See notes on page 127.

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APPENDIX B: Quick Setup Configurations

Table B-1 (continued). Quick Setup Configurations.

Default Settings Listed by Mode or Type of Operation

V.25 bis 2-WIRE 4-WIRE BELL

OPTION

HAYES ASYNC¹DUMB LEASED²LEASED²V.33

208³

Misc.

Address

999,999 999,999 999,999 999,999 999,999 999,999 999,999

Dialer

Mode

Hayes V.25 bis/ OFF

Async¹

OFF

Auto Answer Enable

Data Format Async

Character

Enable Enable

Disable

Sync

Disable Disable Enable

Data

Format

Options

Async¹

Async

Sync

Length

Parity

None

Even¹

None

Disconnect RX Space

Options

Disconnect

Enable Enable¹Enable

Enable

OFF

Enable Enable Enable

TX Space

Disconnect

Carrier

Disconnect

Enable

OFF

Enable Enable

Line Current

Disconnect

RTS

Disconnect

OFF

Test

Options

DSR During

ALB

Remote Test Enable

Enable Enable

True Normal

Normal Normal Normal

True Normal Normal

Enable

Normal

True

Enable Enable Enable

Normal Normal Normal

EIA

Options

CTS to EIA

CD to EIA

DSR to EIA

True

Normal

DTR from

EIA

Normal Normal Normal

True

Normal

ALB—DET

controlled

Disable Disable Disable Disable

Disable Disable Disable

See notes on page 127.

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Modem 34336

Table B-1 (continued). Quick Setup Configurations.

Default Settings Listed by Mode or Type of Operation

V.25 bis

2-WIRE 4-WIRE

BELL

OPTION

HAYES ASYNC¹DUMB LEASED²LEASED²V.33

208³

EIA

Options

(continued)

RDL—DTE

controlled

Disable Disable Disable Disable Disable Disable Disable

Normal Normal True True True True True

TM to EIA

Modem

Setup

Options

CD Level,

Leased

-26 dBm -26 dBm -26 dBm -26 dBm -26 dBm -26 dBm -26 dBm

-51 dBm -51 dBm -51 dBm -51 dBm -51 dBm -51 dBm -51 dBm

CD Level,

Dial

TX Level,

Leased

0 dBm

0 dBm 0 dBm 0 dBm

TX Level,

Dial

Permis. Permis. Permis. Permis. Permis. Permis. Permis.

Signal Quality

Level

10^3

T-III

10^3

T-III

10^3

T-III

10^3

T-III

10^3

T-III

10^3

T-III

Compromise

Equalizer

T-III

Trellis Code

Enable

Enable Enable Enable

Transmit

Clocking

Internal Internal Internal Internal Internal Internal Internal

T1 Timer

0.8 sec 0.8 sec 0.8 sec 0.8 sec

0.8 sec 0.8 sec 0.8 sec

Enable Enable Enable

See

Auto-retrain

Enable

Enable Enable Enable

See

Answer/

Originate

ORIG

note 2

ORIG

Answer Tone 2100Hz 2100Hz 2100Hz 2100Hz 2100Hz 2100Hz 2100Hz

Front Panel

Enable

Enable Enable Enable

Speaker

Control

Till-CD

Till-CD Till-CD Till-CD

Speaker

Volume

High

OFF

High

OFF

High

OFF

High

OFF

High

OFF

High

OFF

High

OFF

Guard Tones

V.13

Operation

OFF

See notes on page 127.

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APPENDIX B: Quick Setup Configurations

Table B-1 (continued). Quick Setup Configurations.

Default Settings Listed by Mode or Type of Operation

V.25 bis 2-WIRE 4-WIRE BELL

OPTION

Carrier

CTS

HAYES ASYNC¹DUMB LEASED²LEASED²V.33

208³

V.33 and

Bell 208A/B

options

Switched Switched⁴Switched Switched Switched Constant Switched

RTS

RTS⁴

0⁴

RTS

150 ms

None

OFF

RTS-CTS

Delay

Auto-

Recovery

Options

Auto-Recovery

Select

None

OFF

20 min

None

OFF

20 min

None

OFF

20 min

None

OFF

None

OFF

Return from

Auto-Recovery OFF

Auto-Recovery

Test Interval 20 min

20 min 20 min 20 min

LCD

Panel

LCD

Intensity

See notes on next page.

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Modem 34336

Table B-1 (continued). Quick Setup Configurations.

Notes:

¹V.25 bis synchronous configurations (character- and bit-oriented) are the same

as the V.25 bis asynchronous confiugration except as follows:

• V.42 MODE is OFF

• BUFFER is disabled

• DATA FORMAT is synchronous

• PARITY is ODD

• RX SPACE DISCONNECT is disabled

• TX SPACE DISCONNECT is disabled

• DIALER MODE (V.25 bis) is: Sync_c for character-oriented mode,

Sync_b for bit-oriented mode.

²Leased line originate and answer Quick Setups [(ORG) and (ANS) on the LCD]

are the same except that ANSWER/ORIGINATE is set to ORIGINATE for the

originate Quick Setups and is set to ANSWER for the answer Quick Setups (2-

wire or 4-wire).

³The V.32/208 auto-mode Quick Setup configuration is the same as the Dumb

mode Quick Setup configuration except as follows:

• SPEED TYPE is AUTO

• DATA FORMAT is synchronous

• V.13 OPERATION is set to TX and RX

• CARRIER is constant

• Summary Setup V.32/208 option (data pump options group) is

set to 1 (enable).

⁴Effectve for synchronous modes only.

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APPENDIX C: Summary Setup

Appendix C: Summary Setup

C.1 Introduction to Summary Setup

Summary Setup is designed to allow experienced users to quickly change

option settings for any mode. There are three Summary Setup screens:

SETUPS, AT PROFILES, and S-REG. They are briefly described on the

next page.

Because the screens show numerical codes with very little explanation,

Summary Setup is recommended for experienced users only. Changes

made through Summary Setup modify the active modem configuration

and are saved to memory when you exit Summary Setup.

ACCESSING SUMMARY SETUP

Summary Setup is accessed from screen 6 of the SETUP menu. The

SUMMARY screen includes a four-digit checksum value to the right of the

word SUMMARY. This number changes if any of the option settings are

changed. You can determine if any of the modem’s settings were changed,

but you cannot determine what options were changed.

From the SUMMARY screen, choose SETUPS to change options, AT to

change options that are associated AT commands, or S-REG to change S

KEY TO THE SUMMARY SETUP SCREENS

Each Summary Setup Screen is essentially the same: brief descriptive

information on the top line and a long string of numbers on the bottom line.

The numbers are broken down into groups that represent a category

of options (for example, EIA interface options).

Each digit position represents an option, and the number in each digit

position indicates the current option setting (parameter). The diagrams

in this appendix show the following information:

• Which options are included in each option group

• Which option is indicated by each digit position within the group

• The possible parameters for each option.

NOTE

The number in each digit position is the current iption setting

(parameter). The diagrams of this Appendix show the factory-default

setting for each option.

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Modem 34336

MAIN MENU

<1>

MAIN MENU

<2>

TALK QUICK DIAL

SETUP TEST RMT

SETUP

<1>

SETUP

<6>

TYPE LINE SPEED

SUMMARY

The four-digit hexa-

decimal value in the

upper right corner of

the SUMMARY menu

screen is a checksum

derived from the

Modem’s current con-

figuration. The check-

sum will change when

any of the Modem’s

options are changed.

SUMMARY

609E

SETUPS AT S-REG

PRI

addr

S-REG 00:01

0011214E0 999 99

DEC

INC

The SETUPS screen

allows you to change

all Modem options,

including those that

can be accessed

through the front-panel

LCD and those that

can only be accessed

or changed through

Summary Setup.

The S-REG screen

allows you to change

the S register values.

AT PROFILES

&Y0

Do not change an S

do not know its

function. Doing so

can adversely affect

the configuration.

The AT PROFILES screen

allows you to access and

change the Hayes mode user

profiles (profile 0 and profile 1).

Figure C-1. How to access the Summary-Setup Screens.

136

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Appendix C: Summary Setup

C.2 SETUPS Screen

PRI

addr

Only part of the SETUPS screen can be

displayed at any one time. The full screen

is displayed below next to the numbers 1,

2, and 3.

0011214E0 999 99

To make configuration and viewing easier, the screen is broken down into a

number of sections. Use the front-panel pushbuttons to move around within

the SETUPS screen (see Figure C-2).

PRI

addr

dial

eia

v42<1>

0011214E0 999 999 11111002210 000100000 20334300

v42<2>

L.L.

pump1

pump2

pump3

210001021 10000010 30100101100 00000110 00000000

misc1

misc2

misc3

1141110 0000 001FFFF1 71000000

Primary Options:

PRI

0011214E0

Speed limit, type: 0=V.32/V.32bis, 1=V.33, 2=Bell 208

Speed limit, min. (bps): 4=19.2 K, 5=16.8 K, 6=14.4 K, 7=12.0 K, 8=9600,

9=7200, A=4800, B=2400, C=1200, D=600, E=0-300, F=1200/75

Speed limit, max. (bps): 4=19.2 K, 5=16.8 K, 6=14.4 K, 7=12.0 K, 8=9600,

9=7200, A=4800, B=2400, C=1200, D=600, E=0-300, F=1200/75, G=EIA 23

Buffer mode/speed conversion: 0=disable, 1=enable

V.42 mode: 0=off, 1=mandatory, 2=automatic

Dialer mode: 0=off, 1=Hayes, 2=DTR dialing, 3=V.25 bis–async

4=V.25bis–sync/character-oriented, 5 =V.25 bis–sync/bit-oriented

Character length (bits): 0=9, 1=10, 2=11

Data format: 0 =Async,1=Sync

Line type: 0=2-wire dial, 1=2-wire leased, 2=4-wire leased

NOTE

Speed limit, min. and Speed limit, max.: 7200 bps parameters are

available only if V.32 bis mode is enabled.

137

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Modem 34336

Primary Options:

addr

999 999

Move the

cursor one

position to

the left

Move the

cursor one

position to

the right

Exit to the

AT Profiles

Screen

TRANSMITTER

RECEIVER

Group

Unit

address address

Move the

Increase

Move the

cursor to

the next

section of

commands

cursor to

the previous

section of

the value of

the blinking

character

by one

commands

Figure C-2. How to move the cursor

in the SETUPS screen using the

pushbuttons.

Dial Line Options:

dial

11111002210

Pulse dialing rate (pulses per sec): 0=10, 1=20

Wait for carrier (sec): 0=30, 1=45, 2=60, 3=75

T1 timer (sec): 0=0, 1=0.3, 2=0.8, 3=1.6, 4=3.0

Carrier detect level, dial (dBm): 0=-26,1=-33, 2=-43

TX level, dial: 0=permissive, 1=programmable

Disconnect, RTS (sec): 0=off, 1=140, 2=120. . . 7=20

Disconnect, line current: 0=disable, 1=enable

Disconnect, carrier: 0=disable, 1=enable

Disconnect, TX space: 0=disable, 1=enable

Disconnect, RX space: 0=disable, 1=enable

Auto-answer: 0=disable, 1=enable

EIA INTERFACE OPTIONS:

e i a

010211000

Test mode: 0=normal, 1=true

Remote digital loopback test: 0=disable, 1=enable

Analog loopback test: 0=disable, 1=enable

CTS: 0=normal, 1=follow RTS, 2=true, 3=on

Carrier detect: 0=normal, 1=true, 2=toggle

DSR: 0=true, 1=normal, 2=crossover

DTR: 0=normal, 1=true

138

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Appendix C: Summary Setup

V.42 ERROR CORRECTION OPTION:

NOTE

“V42 <1>” and “V42 <2>” are displayed to help indicate the relative

positions of individual options across the LCD.

V42 <1> V42 <2>

00335311 200001021

Link flow control: 0=disable, 1=enable, 2=slaved

DCE pass-through flow control: 0=disable, 1=enable

Selective retransmission: 0=disable, 1=enable

V42 bis: 0=disable, 1=enable

V.42 protocol: 0=LAPM only, 1=MNP only, 2=LAPM/MNP

DTE pass-through flow control: 0=disable, 1=enable

Flyback buffer: 0=enable, 1=disable

Break handling: 0=none, 1=destr./expedited,

2=nondestr./expedited, 3=non-destr./non-expedited

MNP class (limit): 0=class 1, 1=class 2, 2=class 3,

3=class 4, 4=class 5

Flow control, DCE to DTE: 0=none, 1=CTS, 2=DC1/DC2,

3=DC1/DC3

Flow control, DTE to DCE: 0=none, 1=RTS, 2=DC1/DC2,\

3=DC1/DC3

Parity: 0 =none, 1=odd, 2=even, 3=mark, 4=space

DTE speed (bps): 0=115.2 K, 1=57.6 K, 2=38.4 K, 3=19.2 K,

4=9600, 5=7200, 6=4800, 7=2400, 8=1800, 9=1200,

A=600, B=300

LEASED LINE OPTIONS:

L. L.

10020010

Auto-recovery test interval (min): 0=10, 1=20, 2=40, 3=60

Auto-recovery return (sec): 0=off, 1=10, 2=40, 3=60, 4=120

Auto-recovery select: 0=none, 1=dial if bad 30 sec,

2=dial if bad 1 min, 3=dial if bad 2 min, 4=dial if bad 3 min,

5=dial if bad 4 min, 6=manual recovery

Carrier detect level, leased (dBm): 0=-26,1=-33, 2=-43

TX level, leased (dBm): 0=0,1=-1 . . . 9=-9, A=-10 . . . F=-15

TX clocking: O=internal, 1=received clocking, 2=external

Answer/originate: 0=answer, 1 =originate

139

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Modem 34336

DATA PUMP OPTIONS:

NOTE

“pump1” and “pump2” are displayed to help indicate the relative

positions of individual options across the LCD.

These five options apply to the Modem

pump1

pump2

(MD833A–R2) only.

2002103010100011110

208 phase detection: 0=normal, 1=compensated

V.32 mode: 0=V.32 extended, 1=V.32 bis

Rate renegotiation (RRP): 0=disable, 1=enable

Turnaround delay: 0=on, 1=off

Satellite delay: 0=disable, 1=enable

RTS to CTS delay (ms): 0=none, 1=15, 2=50, 3=150

CTS: 0=always ON, 1=follow RTS

Carrier type: 0=switched, 1=constant

Phase reversal in answer tone: 0=enable, 1=disable

Auxiliary channel: 0=disable, 1=enable

Speed fallback: 0=disable, 1=enable

Trellis coding: 0=disable, 1=enable

Answer tone: 0=2100 Hz, 1=2225 Hz

Guard tone: 0=off, 1=550 Hz, 2=1800

Auto-retrain: 0=disable, 1=enable

Signal quality level (error/bits): 0=1 in 103,1=1 in 105

Compromise equalizer type: 0=off,1=I, 2=II, 3=III, 4=IV

140

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Appendix C: Summary Setup

MISCELLANEOUS OPTIONS:

NOTE

“misc1” and “misc2” are displayed to help indicate the relative positions

of individual options across the LCD. The dashes (-) are shown in this

example to help indicate the relative positions of these three particular

options across the LCD.

misc1

misc2

1230000 0100

––

–

Multimode handshake: 0=T1 timer, 1=V.32 bis Annex A

Answer tone detection: 0=disable, 1=enable

ALB make busy: 0=disable, 1=enable

V.13 operation: 0=off, 1=TX only, 2=RX only,

3=TX and RX

DTE=DCE speed: 0=disable, 1=enable

V.25 bis DTR dialing: 0=disable, 1=enable

Operating mode fallback: 0=Bell 212A and

Bell 103,1=V.22/V.21/V.23

Remote test: 0=disable, 1=enable

DSR during ALB: 0=disable, 1=enable

FP: 0=disable, 1=enable

LCD intensity: 0,1 . . . 7 (7=greatest intensity)

Speaker volume: 0 =low, 1=medium, 2=high

Speaker control: 0=off, 1=on till CD, 2=on,

3=off during dialing

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Modem 34336

C.3 AT PROFILES Screen

From the AT PROFILES screen you can select a Hayes mode configuration

profile (either 0 or 1). Only part of the profile can be displayed at one time.

The selected profile is used as the active configuration and is also designated

as the default user profile.

• Press pushbutton 1 to select profile 0.

• Press pushbutton 2 to select profile 1.

• Press pushbutton 3 to toggle between profile 0 and profile 1 as the

default. You can achieve the same effect by issuing the &Y command

(&Y0 or &Y1).

AT PROFILES

&Y0

Factory-default settings are shown below.

ATbeflmqvxy AT&c

010210141

Move the

cursor one

position to

the left

Move the

cursor one

position to

the right

Exit to the

AT Profiles

Screen

TRANSMITTER

RECEIVER

The screen intially

displays the

Move the

cursor to

the previous

section of

commands

Increase

Move the

cursor to

the next

AT commands

and one

AT& command.

the value of

the blinking

character

by one

section of

commands

ATbeflmqvxy AT&cdgjlpqrsx s00 s18 s25 s26 AT\abcdeh kmnpq t vx

010210141

1210000000 001 000 005 001

3150101630323300100

S Registers

AT\ Commands

(most are for V.42 options)

AT& Commands

AT Commands

Figure C-3. Selecting a Profile.

NOTE

Refer to Table 5-1, Hayes Compatible Commands, for an explanation of

the commands represented in this diagram.

142

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Appendix C: Summary Setup

C.4 S-REG Screen

The S-REG screen may be used to read or change the value stored in an S

NOTE

Not all S registers are intended for user access. Do not change the value

of an A register if you do not know the register’s function. Doing so can

adversely affect the modem’s configuration.

The S-REG Screen displays an S register number and the value currently

stored in the displayed S register.

HOW TO CHANGE S REGISTER VALUES

Select the desired S register number, then modify its value, as follows: Use the

arrow pushbuttons to move the LCD cursor from one digit to the next. Then

select DEC or INC to decrease or increase the selected (blinking) value until

the desired value is displayed.

S registers can also be changed by using the Hayes mode S command,

as explained in 5.0 Hayes Emulation Mode.

Stored value,

S register number

(decimal)

or the value to be stored

(hexadecimal)

S-REG 00:01

DEC

INC

Decrease the value

of the blinking

Increase the value

of the blinking

character by one

Figure C-3. Changing the S Register Value.

143

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Modem 34336

Appendix D: Jumpers

WARNING

Jumpers should be switched only by qualified service personel.

For most applications, there is no need to reset the modem’s internal jumper

switches. However, a jumper switch will have to be reset if you need to do any

of the following:

• Connect frame ground to signal ground.

• Switch from A/A1 control to MI/MIC control.

• Strap the modem for use in a DC rack enclosure.

• Change the function of EIA interface pin 25.

If you need to reset a jumper switch, refer to the next page to determine the

jumper that should be switched, where it is located, and how it should be set.

The jumpers are numbered on the circuit board; for example, JP4 is jumper

4. To access the jumpers, unscrew the four screws on the bottom of the

modem and carefully lift off the cover.

WARNING

Improper setting of AC and DC power jumpers could result in serious

damage to the modem.

144

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Appendix D: Jumpers

JP2

JP4

JP7

JP1

JP3

JP6

JP5

JP8

Figure D-1. Modem Circuit Board—Jumper Locations.

145

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Modem 34336

Table D-1. Jumper Switch Functions.

JUMPER(S)

Pins 1 and 2 connected Pins 2 and 3 connected

JP1

Frame and signal

ground connected

Frame and signal

ground not connected

JP2

-12/-24/-48 VDC operation

JP3, JP4

-12/-24/-48 VDC operation

(Set to same

position)

JP5, JP6

A/A1 control

MI/MIC control

(Set to same

position)

JP7

Pin 25 used for analog

loopback (input)

Pin 25 used as test

mode indicator (output)

JP8

For factory use only. Do not change JP8 setting!

Factory settings are shown in bold face.

For each jumper, pin 1 is identified by a “1” printed on modem circuit board.

(The JP2 pin 1 label may be difficult to read; JP2 pin 1 is the pin closest to

the edge connector.)

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NOM Statement

NORMAS OFICIALES MEXICANAS (NOM)

ELECTRICAL SAFETY STATEMENT

INSTRUCCIONES DE SEGURIDAD

1. Todas las instrucciones de seguridad y operación deberán ser leídas antes de

que el aparato eléctrico sea operado.

2. Las instrucciones de seguridad y operación deberán ser guardadas para

referencia futura.

3. Todas las advertencias en el aparato eléctrico y en sus instrucciones de

operación deben ser respetadas.

4. Todas las instrucciones de operación y uso deben ser seguidas.

5. El aparato eléctrico no deberá ser usado cerca del agua—por ejemplo, cerca

de la tina de baño, lavabo, sótano mojado o cerca de una alberca, etc..

6. El aparato eléctrico debe ser usado únicamente con carritos o pedestales que

sean recomendados por el fabricante.

7. El aparato eléctrico debe ser montado a la pared o al techo sólo como sea

recomendado por el fabricante.

8. Servicio—El usuario no debe intentar dar servicio al equipo eléctrico más allá

a lo descrito en las instrucciones de operación. Todo otro servicio deberá ser

referido a personal de servicio calificado.

9. El aparato eléctrico debe ser situado de tal manera que su posición no

interfiera su uso. La colocación del aparato eléctrico sobre una cama, sofá,

alfombra o superficie similar puede bloquea la ventilación, no se debe colocar

en libreros o gabinetes que impidan el flujo de aire por los orificios de

ventilación.

147

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Modem 34336

10. El equipo eléctrico deber ser situado fuera del alcance de fuentes de calor

como radiadores, registros de calor, estufas u otros aparatos (incluyendo

amplificadores) que producen calor.

11. El aparato eléctrico deberá ser connectado a una fuente de poder sólo del

tipo descrito en el instructivo de operación, o como se indique en el aparato.

12. Precaución debe ser tomada de tal manera que la tierra fisica y la polarización

del equipo no sea eliminada.

13. Los cables de la fuente de poder deben ser guiados de tal manera que no

sean pisados ni pellizcados por objetos colocados sobre o contra ellos,

poniendo particular atención a los contactos y receptáculos donde salen del

aparato.

14. El equipo eléctrico debe ser limpiado únicamente de acuerdo a las

recomendaciones del fabricante.

15. En caso de existir, una antena externa deberá ser localizada lejos de las lineas

de energia.

16. El cable de corriente deberá ser desconectado del cuando el equipo no sea

usado por un largo periodo de tiempo.

17. Cuidado debe ser tomado de tal manera que objectos liquidos no sean

derramados sobre la cubierta u orificios de ventilación.

18. Servicio por personal calificado deberá ser provisto cuando:

A: El cable de poder o el contacto ha sido dañado; u

B: Objectos han caído o líquido ha sido derramado dentro del aparato; o

C: El aparato ha sido expuesto a la lluvia; o

D: El aparato parece no operar normalmente o muestra un cambio en su

desempeño; o

E: El aparato ha sido tirado o su cubierta ha sido dañada.

148

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1000 Park Drive

•

Lawrence, PA 15055-1018

•

724-746-5500

•

Fax 724-746-0746

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