Tandy 1400 LT User Manual

Cat. No. 25-3510

1200

bps Modem

For

Tandy

1400 LT

User's

Manual

i

ft

ft

ft

1200 bps Modem

for

Tandy®

1400

LT

User's

Manual

©

1987,

Tandy Corporation,

All Rights Reserved

Table of Contents

Chapter 1

Introduction

1

.

Introduction

1-1

LI What is a Modem?

1-1

1.2

Make

a

Call or

Answer

1-2

1.3

Use

Your Modem with a Database

1-2

1.4

Easy to Use

1-3

1.5 Introduction to Modem Features

1-3

1.6 How to Use this Manual . . .

. 1-3

Chapter 2

Installation

2.0 Getting Ready

2-1

2.1

Connecting Your Tandy Modem to

the

Telephone Line

2-1

2.2

Connecting Your Modem

to

Your Computer

2-2

2.3

Installation

2-2

2.4

Auto

Answer

2-4

2.5

Testing Your Modem

2-5

Chapter

3

Testing

Your

Modern

3.0 Testing

the

Tandy

Internal

Modem

3-1

3.1

Performing

the

Local

Analog

Loopback

Test

3-1

3.2

Remote

Digital

Loopback

t 3.3

Chapter

4

Introduction

to

Modem

Operation

4.0

Direct

Entry

into

the

1200 BPS

Internal

Modem

Command

Mode

4_1

4.

1

Functional

States

4_1

4.2

Changing

of

States

4-2

4.3

Command

Syntax

4.4

4.4

Command

Results

4_5

4.5

Speed

of

Transmission

4_g

4.6

Dialing

with

Examples

4-9

4.7

Auto

Answer

Mode

4-15

Chapter

5

Command

Summary

5.1 A

-

Answer

Immediately

5-1

5.2 A/

-

Repeat

Last

Command

5-2

5.3

C

-

Carrier

Signal

Control

5-3

5.4

D

-

Dialing

Command

5-4

5.5

E

-

Echo Back

Control

5-4

5.6

F

-

Set

Communications

Mode

5-5

5.7

H

-

Hook

Control

5-6

5.8

M

-

Monitor Speaker Control

5-7

5.9 O

-

Return

to

On-line State/Initiate

Retrain Sequence/RDL

Test

5-8

5.10 P

-

Pulse Dialing

5-9

5.11

Q

-

Quiet Mode Control (Result Codes)

5-9

5.12

R

-

Reverse

Mode

5-10

5.13

Sr?

-

Determine Status

of

a

Register

5-10

5.14

Sr=n

-

Change Register Value

5-11

5.15 T

-

Touch

Tone

Dialing

5-11

5.16 V

-

Result Code Control

5-12

5.17 W

-

Wait for Dial Tone

5-13

5.18 X

-

Extended

Result

Code Set

5-13

5.19

Z

-

Modem Reset

5-15

Chapter

6

Modem

Registers

6.1 The Set Command

6-1

6.2 Reading and Changing

Registers

6-2

6.3 Register SO

-

Auto Answer

6-3

6.4 Register SI

-

Rings

Passed

6-4

6.5

Register

S2

-

Escape Code

ASCII

Value

6-4

6.6 Register

S3

-

Command Terminator

ASCII

Value

6-5

6.7 Register S4

-

Line Feed ASCII Value

6-6

6.8 Register S5

-

Back Space

ASCII Value

6-6

6.9

Register

S6

-

Wait for Dial

Tone Time Period . . .

6-6

6.10 Register S7

-

Wait for

Carrier Time Period

6-7

6.11 Register S8

-

Pause Time of Comma

6-7

6.12 Register S9

-

Carrier Signal

Detect Time

6-8

6.13 Register

S10

-

Carrier Loss

to

Disconnect

Delay Time

6-9

6.14 Register Sll

-

Speed Control for

Touch

Tone

Dialing

6-10

6.15 Register S12

-

Escape

Code

Guard Time

6-10

6.16

S13

-

S16

Status

Registers

6-11

6.17 Programming

Suggestions

and Considerations 6-15

6.

18

Command

Executions

.

6-15

6.19 Escape

Code

Precaution

6-16

Appendices

Appendix

A

-

ASCII

Code

Chart

App-1

Appendix B

-

Technical

Information

App-5

Addendum

Addendum

A

Add-1

Introduction

Chapter 1

INTRODUCTION

1.0 Introduction

Welcome

to

the world of

personal computer

communications-

You

have purchased Tandy's 1200

bps

internal modem for the Tandy

1400 LT. With this system and

your personal

computer,

you can

call

information sources, such

as

Dow Jones News

Retrieval, ex-

change

information with mainframes,

minis, or

personal comput-

ers, and

transfer files.

The Tandy system you

have purchased

contains several elements:

1)

The modem card.

2)

A modular

telephone cable.

3)

This

manual, which provides

complete

installation and oper-

ating instructions.

1.1 What is a

Modem?

A

modem allows

your computer

or terminal to

communicate with

another

terminal

or computer over the

phone lines.

The word

"modem" is an

acronym for

MOdulator/DEModulator. A

modem

converts

digital data,

generated by

the

computer,

into analog, or

l~l

Chapter

1

audio

tones,

suitable

for

transmission

over

regular

telephone

lines.

When

you send

data

to

another

computer,

your

modem

translates

the

computer

data

into

audio

tones.

At the

other

end,

the

modem

attached

to the

remote

computer

"demodulates"

the

audio

data

back into

the digital

language

of

the

computer.

1.2

Make

a Call

or

Answer

Your

modem is

able

to dial

automatically,

either

pulse

or

touch-

tone,

and

communicate

with

time-sharing

services

or other

com-

puters

as well

as answer

incoming

calls.

When

your

modem

is

in

the

Originate,

or

Call Mode,

it

means

that

your

modem

is

set

up

to

make

a call.

Your

modem

is

expecting

another

modem

at the

other

end

to answer

the

call.

Conversely,

you can

set

your modem

to the

Answer

Mode,

meaning

that any

time

a call

comes

in,

your

modem

will

answer.

(If

you expect

to be

receiving

many

data calls,

it's

a

good idea

to

install

an extra

phone line.

When

you're

set

to

auto-answer,

the

modem

will

answer the

phone

regardless

of

whether

there

is

a

modem

or

a human

at the other

end!)

1.3

Use

your

Modem

with

a

Database

Once the

computer

is

connected

to

telephone

lines

it can

commu-

nicate

with

other

computers.

For

example,

you can

use

your

PC

and

modem

to

call

an

information

utility

such

as Dow

Jones

News

Retrieval

or

The

Source.

Dow

Jones and

The

Source are

large

computer

databases,

whose

information

is

rented

to

the

public.

1-2

Introduction

Once

you

are connected

to one

of them,

you

can, for example,

read

the

latest

stock quotes or the morning's Wall Street Journal.

1.4 Easy-to-Use

Your

Tandy

1200

bps

internal modem is made to be easy to

use.

More and more

applications for the

PC

and

your

modem are

be-

coming available.

Now,

for example,

you

can plan your

travel

by

linking with the latest airline schedules or

check your bank bal-

ance from the comfort of your living room. In the

future, the

uses

for your modem will continue to grow.

1.5 Introduction to Modem Features

Your modem has many

advanced features, such

as:

1)

Auto-dial and

auto-answer: no telephone is required.

2)

Powerful automatic dialer commands compatible with virtu-

ally all of the

communications software available.

3)

Can

be

used with an

acoustic coupler.

1.6 How to

Use

This Manual

This manual should

be

used

in conjunction

with your software

manual. Chapter

2 includes complete

installation instructions.

1-3

Chapter

1

Chapter

3 covers testing

the

modem.

More

technical information

about the

modems internal

command

set is included

in Chapters 4

through

6.

1-4

Installation

Chapter 2

INSTALLATION

2.0 Getting

Ready

This chapter will explain installation of

the Tandy 1200

bps

inter-

nal modem.

2,1 Connecting Your Tandy

Modem to the

Telephone Line

In order to operate, your

modem must be

connected

to a

tele-

phone line. Your modem is FCC registered for direct

connection

to

the

telephone line. Before proceeding, you should call your lo-

cal telephone company and

inform them that

you

are going to

connect registered equipment.

Follow these steps:

Inform the local telephone company that

you

are

connecting regis-

tered equipment. Give them the

following information:

Manufacturer: Tandy

Corp.

Fort Worth, TX

Model: 1200 bps

Internal Modem

Registration:

AU692V25-35 10

Ringer Equivalence:

0.4B

2-1

Chapter

2

Your modem

has

been

registered with

the

Federal

Communica-

tions

Commission

and

is approved

for

connection

to any standard

telephone

line in the

United

States.

2.2

Connecting

Your Modem

to

Your

Computer

The following

steps

will

explain installation

of your

1200

bps inter-

nal

modem

in your

computer.

PLEASE

FOLLOW

THESE IN-

STRUCTIONS

CAREFULLY.

NOTE:

Whenever

you are

installing

or

removing

boards

in

your computer,

make

sure

that the POWER

IS

SWITCHED

OFF.

NEVER

INSERT

OR

REMOVE

THE

MODEM WHEN

THE

POWER

IS ON.

2-2

2.3

Installation

Installation

S*

1

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MODEM OPTION

X

SLOT

COVER

1

e

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®\yAy/Q

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-it- :v_cc EXTER\A

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DIS*

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SCREWS'

To Install:

1)

Remove the slot cover

over

the "Modem Option" slot on the

back of the

computer.

It is held in

place

by two

small s crews -

2)

Gently slide

in the

modem

as

illustrated. Press in to ensure

that

it is seated securely in the

connector.

Use the

screws that

held the cover to secure the modem into the

computer.

2-3

Chapter

2

ACOUSTIC

COUPLER

JACK

RJ11C

3)

There

are

two

modular

phone

connectors

on

the rear

panel

of

the

Tandy

1200

bps internal

modem.

Connect

one end

of

the

modular

phone cable

supplied

with

the

modem

into

either

of

these

two

jacks.

These

jacks

are identical;

it

does not matter

which

one

you use.

Connect

the other

end

of this

modular

cable

into

your wall

jack.

NOTE:

The

second

jack

on the

back of

the

modem

can

be

used

to connect

your

standard

telephone.

This

is

provided

for

your

convenience.

You

may plug

your telephone

into

this

jack

and

continue

to use it

normally.

The

modem

can

be left

2-4

Installation

connected even

when

your computer

is turned off.

It will

not

affect

the

normal

use

of your telephone.

4)

If

you will

be using the Tandy

Acoustic

Coupler, insert

the

connector

into

the holes marked

Acoustic

Coupler.

There

is

only

one

way to insert the

connector.

TELEPHONE

CABLE

\_

ACOUSTIC

COUPLER PLUG

ACOUSTIC COUPLER

JACK

5)

You are

now ready

to

initialize

the modem.

Begin from

the

DOS

prompt

"A:"

While

holding

down

the Ctrl and

Alt keys,

press

the Ins

key.

This

will bring

up the Tandy 1400

LT

Set

Up Menu.

6)

Press the F4 key

to

highlight

the RS232C /

Internal

Modem

option.

Press the right

arrow key to

highlight MODEM.

Press

ENTER.

7)

Press

the F5

key to highlight

the Direct Modem /

Acoustic

Coupler

option. Press

the arrow

keys

to

highlight DIRECT

if

you will

be

connecting

the modem

directly

to

the

phone line

or

to ACOUST

if

you will

be

using the Acoustic Coupler.

Press ENTER

and then escape to return

to DOS.

8)

You

are now ready to

use the modem. Note

that

you do not

need

to

reinitialize

each

time

you

use the modem.

However,

2-5

Chapter

2

each

time

you

switch between direct

use

and

the

acoustic

cou-

pler, you will need to reinitialize, following steps

5-7.

2,4

Auto

Answer

Your modem is set up to automatically

answer incoming calls. The

auto answer function

is controlled

by

the SO register.

If

you wish

to disable auto answer, access the modem command

set

with

your

communications software and

enter

the

command ATS0=0<CR>.

See section 4,7 for additional information.

2.5

Testing Your

Modem

So that

you

can make sure that your equipment is correctly in-

stalled and

working, your modem can perform several self tests.

Consult

Chapter 3 for instructions.

2-6

Testing

Your Modem

Chapter

3

TESTING

YOUR

MODEM

3.0 Testing

the

Tandy Internal

Modem

So that

you can make

sure that

your equipment

is

correctly in-

stalled

and working,

your 1200

bps internal

modem can

perform

several

tests

to check the

modem's

local and

on line

modes.

3.1

Performing

the

Local

Analog

Loopback

Test

These

tests check

the

modem's

Originate and

Answer

modes. Be-

fore

you perform

these tests,

disconnect

the phone

cable from the

wall

jack to the

modem. If

this

cable is

not

disconnected,

the

test

results

may not be

valid. After

performing

the

tests,

be sure

to

plug

this cable

back

in.

To

perform the

tests:

1)

Turn

your computer

on.

2)

Use your

communications

software

to access the

modem's

local

command

set.

3)

To

test the Originate

Mode, type in the

command:

AT

S16=l

CI

D<CR>

3-1

Chapter

3

If the modem is correctly

installed, it should respond:

CONNECT

At this point every

character entered

from

the

keyboard

goes to

the modem's

transmitter section and, instead

of going

out

over the

phone line, is rerouted to

the modem's receiver section.

From

here,

the characters are

displayed

on

the screen.

The key

you

press

should match the character

displayed on the screen,

4)

To

exit the test, enter:

+++

Do not enter

<CR>

after +++.

The modem responds:

OK

5)

If you do not

wish

to test

the answer

mode, proceed

to

step 7.

Now,

if you wish to test

the Answer Mode,

type

in

the com-

mand:

AT S16=l A<CR>

The modem should respond:

CONNECT

As with the Originate

test,

every character

entered from the

keyboard should match the

character displayed on the

screen.

6)

To exit the test,

enter:

+++

Do

not enter <CR> after

+++.

The modem responds:

OK

7)

Enter:

AT S16=0H<CR>

3-2

Testing

Your

Modem

The modem

responds:

OK

This resets

register

S16

and frees the modem

for normal

opera-

tions.

8)

Remember

to plug

the

phone cable

back

in before making

a

call.

If

there is

a problem:

1)

Is

the modem

firmly

seated in the

expansion slot?

2)

Double

check

that

you

have

disconnected

the phone line.

3.2

Remote

Digital

Loopback

RDL

is an

advanced

test feature which

allows one modem

to re-

quest the remote

modem

to

"loopback"

data

sent

to it. The RDL

feature

allows

you to

make

a complete

unattended

test of the re-

mote

modem. Your

local modem

sends the data over

the phone

lines to the

remote

modem. The remote

modem will

then loop-

back whatever

is sent, and

you should see

your test message

ap-

pear

on your screen

exactly

as you sent it.

This

test must

be

performed

when the modems

are on line.

To

begin

the

test,

you must enter the

command mode,

using the +++

escape

code. Once on line

and in command

mode,

you

can tell

the

modem

to begin

the

test.

1)

In

command mode,

enter:

AT02<CR>

3-3

Chapter

3

The

test is now underway.

The

message CONNECT

followed

by OK will be displayed.

Note

that a result

code of ERROR

indicates

that the remote

modem is not

capable

of responding

to RDL

or has not

been

conditioned

to do so.

2)

Enter

a test message:

How now brown

cow.

3)

Check

to

see

whether

your

test

message

is appearing

on the

screen

exactly

as

you

entered

it.

4)

To

end the

test, enter:

+++

5)

Modem should

respond:

OK

You are

now in command

mode.

6)

Enter:

AT01<CR>

7)

Modem

responds:

CONNECT

The

test is ended

Notes:

1)

RDL is

automatically terminated

when

the connection is

dis-

continued.

2)

If the line

is disconnected

during RDL (the

phone

line is

pulled

out of the

wall, etc.), the requesting

modem will reset.

This

prevents

an unexpected request

for RDL during

the next

call.

3)

Your modem

will always

respond to RDL when on-line.

The

modem will

respond to and

initiate RDL;

it

does

not matter

which modem

placed the original

call.

3-4

Testing

Your Modem

4)

Note that

the

00 command

returns

you to your

previous

state.

So

if

you enter

ATO0<CR>

once

you

have

initiated

RDL, the

command

will

NOT

exit

the

RDL

mode

when re-

turning

on line.

To exit

RDL

and return

on

line,

you

MUST

enter

AT01<CR>.

If your

modem

has echoed

back

the test message

exactly

as

you

sent it,

your

modem,

the remote

modem, the local

data

terminal

equipment

and

the phone

lines all

check

out.

If

there

is

a

problem:

If

the

test message

does not

echo

back correctly,

either

your

mo-

dem, the

remote

modem,

the data

equipment or the

phone

lines

are

at fault.

If

you have

already

successfully

performed

the local

analog

loopback

test,

you know that

your modem

and

computer

are

communicating

properly.

If there

is

a remote

operator,

he

or

she

may wish

to perform

a local

analog

loopback

test

as well

to

verify

that

the remote

modem

and computer

are

communicating.

Assuming that

both

the local

and

remote modems

have success-

fully

performed

local

analog

loopback

test:

1)

Can

you

hear

your

modem

dialing?

2)

If the

modems are

connecting

but

the

test message

is not

coming

through,

you may have

a problem

with the

phone

lines.

Disconnect

and try again.

3-5

Introduction

to

Modem Operation

Chapter 4

INTRODUCTION TO MODEM OPERATION

4.0

Direct Entry into the 1200 BPS

Internal

Modem Command Mode

This chapter describes the functional

states

of the 1200

bps

inter-

nal modem and

the guidelines

to

follow when sending commands

to it. The

responses

which the

modem sends to your

commands

are also

described.

For those who want to use

the modem's

commands directly,

ac-

cess

the modem

through your communications

software. Then

en-

ter the command AT

Z<CR>

t

which will set

the modem options

to

their default values.

4.1 Functional

States

The modem

will

always be in one

of

two states:

local

command

state or on-line state. In the local command

state, the user is

making commands

to

the

modem via keyboard or

program con-

trol. No data

is being sent

or

received.

The local

command state

is

provided

so

that

the modem can be

commanded to

perform vari-

ous

functions, such

as

changing

configurations and

dialing. In

the

on-line state, the data is

sent and

received over the phone lines.

When on-line, the modem will be

in the

originate mode (when

the modem is

making a call) or the

answer mode (when accepting

4-1

Chapter

4

an incoming call).

Occasionally,

you

may make

use of a special

form

of answer

mode,

called

"reverse

mode,"

which is

used to

initiate a call to

an originate-only

modem

(a 300 baud

acoustic

coupler,

for example).

Changing

between originate and answer

modes

is not something

you need

to worry

about,

because

the mo-

dem makes

the switch automatically.

In normal

operation, the change

from the local command

state to

the

on-line

state

is automatic.

For instance, once

the command

to

dial is

given,

the transition to

the on-line state is

performed auto-

matically

when the connection

to another modem

is

made.

The

on-line state is

also achieved when the

modem answers

a

call.

When

the carrier

is lost, for whatever

reason, the modem auto-

matically returns

to the local

command state.

The

modem will

not respond

to

local

commands when on-line.

If

you wish

to enter

a

command,

you must first return

the modem

to

the

local state. This is

accomplished

by entering the Escape Code.

4.2

Changing of

States

Escape

Code

The escape code is

a message to the modem which

tells it to re-

turn to

the

local state,

allowing

you

to enter commands.

The for-

mat consists

of an

escape guard time and an escape character.

The escape code

does not

drop

the connection with the other mo-

dem; it merely suspends the transmission and reception of

data

over the

line temporarily. The command

to

hang-up, ATH<CR>,

must

be

entered to drop the phone line.

4-2

Introduction

to

Modem Operation

The default escape

code is entered

as

followed:

Wait at least

one second after the last

character entered.

Enter:

+++

Wait

at

least

one second for

the result code.

The modem will

return

to

local

state and respond with

the result

code OK.

NOTE:

The result

code

will

be

returned only

if the options

QO

and

VI are set.

The purpose

of

the

guard time

(the one second delay

around the

+++)

is to prevent the

modem from accidentally

escaping

into

command mode

during normal operation.

The one-second

guard

time

surrounding the escape

code tells

the modem that

"+++"

is

a

command

to the modem,

not

just a

stream

of data.

The default

values

of the

escape code

and

the guard time may

be

changed

(Registers

S2

and

S12). The escape code

must

be a

single

character

entered

three times

and surrounded

by

a

designated

pe-

riod

of time. If you are

in auto-answer

mode, it is advisable

to

disable the escape

code or

set it to

a

different value from

that

of

the originating

modem (See Register

S2

for instructions).

That

way, your modem

will not be accidentally put

into local command

state

by the

distant

modem.

4-3

Chapter

4

4.3

Command

Syntax

Attention

All

commands must

begin with

the letters AT.

AT is short for

"Attention"

and is

used

by

the

modem to automatically

set

the

baud rate and parity, AT

must

be

entered

in upper case;

all other

commands

may

be

in either

upper or

lower

case,

This

command

is

the

signal to the modem

that

what follows is

a command.

Line

Length Limits

AT

may

be

followed

by one or more commands.

The commands

wili be

performed

in the order

given. The

number of

commands

given

at once is limited

by the line length, which

cannot

exceed 40

characters

following AT*

Control

characters and spaces

are not

counted,

but

punctuation marks

such as dashes

or commas

are.

For

example,

the

syntax of

a

command

to

the modem

is as fol-

lows:

AT

<command>

<CR>

Command

Terminator

Note that

<CR> denotes carriage

return.

This is the

command

terminator;

the command

is not

processed until a

<CR> is

entered.

Example:

AT M2 DT

(408)

767-8900<CR>

In this example

there

are two commands: the

M (monitor

speaker)

and

D

(dial).

Notice that

a space has been

put

between

the line elements. This

is optional;

the commands

can

be

entered

one right after

the other.

4-4

Introduction

to

Modem Operation

There are two

parameters shown in this example. The

first (M2)

indicates that

the speaker

will

be

on

at

all times. The

second

command

(DT) tells the modem

to

dial, using

touch tone* the fol-

lowing number. (See

the

D

and

M commands).

Regarding the PHONE

NUMBER: The numbers in

this string

can

be added

together

without the parentheses and dash.

However,

if

it is more

readable

to use

these

delimiters,

the

modem will accept

them.

Line Editing

When entering

commands to the modem,

editing

can be done by

using the

backspace key, which deletes the last

character entered,

The

backspace

key

does

not

delete the attention

code,

"AT."

Note

that

when backspacing over

a

"space,"

the space is ignored

and the next character is erased

regardless

of

whether or not

it

appears properly

on

the screen.

Null Parameters

Commands

to

the modem consist of a letter, such as

D for DIAL,

followed by a

number, or

parameter, generally

0,

1,

or 2. If

a

command parameter is inadvertently or

intentionally left out

the

modem assumes a value of 0. For

instance,

if

a

command were

entered "AT M DT

(555)

555-llll<CR>," it

would

be

equivalent

to

"AT MO

DT

(555)

555-llll<CR>". The

parameter associated

with the M command

would

be

instead of 2 as

in the previous

example. The

result

of this

change would be

to turn the speaker

off.

4.4

Command

Results

After the

CARRIAGE RETURN

("<CR>" above)

has been en-

tered,

the modem returns

a RESULT

CODE after

every operation.

4-5

Chapter

4

This

code may

be

expressed

as

a number

or an

English

word.

The

following

table lists

the

ten

possible

results

and

their

meanings.

Number

(VO)

Word

(VI)

OK

CONNECT

RING

NO

CARRIER

ERROR

CONNECT

1200

NO

DIALTONE

Description

The

command

line

was

successfully

processed.

The

Carrier

signal

has

been

detected.

The

phone

is ringing.

RING

only

indicates

that

the

phone

is ringing.

The

modem

does

not

answer

it

unless

commanded

to

or

unless

auto-

answer

is

en-

abled.

Carrier

was not

detected

or

was lost,

NO

CARRIER

is

displayed

if the

carrier

sig-

nal

from

the other

modem

is not

detected

for

a

suffi-

cient

length

of

time.

NO

CARRIER

means that

a

data

call

was not

success-

fully

completed.

There

was an error

in the

command

line.

Carrier

has

been

detected

at 1200

bps.

No dial

tone

has

been de-

tected

by the

modem

dur-

4-6

Introduction

to

Modem

Operation

7

BUSY

NO ANSWER

ing

the

dial sequence.

This

result

code will only

appear

if

X2, X4 or the

W com-

mand have been

selected.

The

modem has

detected

a

busy signal.

This result

code will only

appear if the

X3,

X4, or

@

commands

have been selected.

The number dialed was

not

answered. This result

code

will only appear

if the

@

command has

been used in

dialing.

Result

Code Notes

The NO ANSWER result

code appears

only when

the mo-

dem

is dialed using the

@

command. See

Section 4.7.

VO

and

VI

are the

modem commands that

determine

whether the modem

is to render numeric

or verbal result

codes, respectively,

The

Q

command

determines

whether or not results

are

sent. In the default

state, the modem

returns

only Codes

0-4.

RING only indicates

that the phone

is

ringing.

The modem

does

not answer it

unless commanded to or unless auto-

answer is enabled.

NO CARRIER

is

displayed if the

carrier signal from

the

other

modem is not detected for a

sufficient length of

time.

NO

CARRIER

means

that

a

data call

was not

suc-

cessfully completed.

4-7

Chapter

4

CONNECT

1200, NO

DIAL

TONE,

and

BUSY

codes are

displayed

only

when

the extended

result

code

set

is en-

abled.

4.5

Speed

of

Transmission

When

the

1200

bps

internal

modem

calls

another system

it

auto-

matically

detects and

adjusts

to

the

transmission

speed

(baud

rate)

at which

your

personal

computer

is operating.

The

transmission

speed

is

thus

governed

by the

device

you have

connected

to

the

modem.

You

must

set the

speed

of your

computer

either

by setting

a

switch

in

the

hardware

or

by a

software

command.

A

command

to

the

modem

will

not

change

the

speed

of

the

equipment.

If

the

1200 bps

internal

modem

is

in

answer

mode,

it

adjusts

to

the

speed

of

the calling

modem.

You

can

use

the X

command

to

tell

the

modem

to inform

you of the

speed

of the

call

it

is

answer-

ing.

For

example,

after

connection,

the result

codes

would

read:

CONNECT

(for

a 110 or

300

baud

connection)

or

CONNECT

1200

(for

a 1200

baud

connection)

Note

that

the

1200 bps

internal

modem

will

accept

a call

from

a

1200

baud or

a

300

baud modem.

Your

computer

must

be set to

the

correct

baud rate

for

the

call.

When

the

modems

begin

to "talk"

to each

other,

your

1200

bps

internal

modem

will

detect the

speed

of

the calling

modem

and

adjust

its

speed to

match.

The modem

will

then

send

a message

to

4-8

Introduction to

Modem Operation

the

screen telling

you at

what speed the

connection

has

been

made. You must then make sure that your computer is also set to

the

correct

baud

rate

(1200,

300)

for the call or the data you re-

ceive

will

be garbled. Most

frequently,

you

will switch speeds \jrith

a

command to your communications software, which will tell the

modem at what

speed to

operate.

If you have

chosen XI, X2, X3, or X4, you

will

be

informed of

the

final connect speed

by

the result

code which appears on your

screen (e.g.,

CONNECT 1200 for a

1200 baud call). In the de-

fault setting

of

X0, the modem will return only the

message CON-

NECT.

4.6 Dialing

with

Examples

Since dialing and answering are the main

functions of the modem,

the

following is

a

summary of the

instructions

for

these operations

with examples.

Dialing

When

a

dial command is given,

the modem is immediately

put

into

originate mode. You are then able

to

call any

distant comput-

er or

timesharing system connected to

a

modem.

The Dial Command is D. This

command

may be

followed

by a

number

of

commands associated with the dial

command,

but in its

simplest form D may

be

followed with only the

number to

be di-

aled.

4-9

Chapter

4

Example:

AT

D

767-8900<CR>

After

entry

of this

command,

the

modem

will

dial

the

number.

You will

hear the

phone

dialing.

The

1200

bps internal

modem

will then

wait

for

30 seconds

(default

time)

for

a

response

from

the

distant

modem.

If

another

modem

answers,

your modem

sends

the

code

CONNECT,

CONNECT

1200, or

1,

or

5, depending

on

what

parameters have

been

set

(See V

command,

X

command).

The

modem

then

goes

on-line,

permitting

you

to

communicate.

If

no

carrier

is

detected,

the

modem

will

hang

up and

send

a

NO

CARRIER,

BUSY,

3,

or

7 result

code,

depending

again

on what

parameters

have

been

set. In its

factory

default

setting,

XO, the

modem

would

respond

CONNECT

when

the

modem

connects,

no

matter

at

what

speed,

and NO

CARRIER

if

the

phone

was

not

answered.

Note that the

modem

will

ignore

the spaces

and

the

dash in

the

previous

example.

You

could

also enter:

ATD5551111<CR>

The

other

commands

associated

with

the Dial

Commands

are

sum-

marized

in

the following

table:

Command

Description

I>

Dial.

The

modem

goes to

originate

mode

and

will

dial

the number

following.

The

following

is

a list

of

subcommands

of the

D

command

and

can only

be used in

conjunction

with

this

command.

4-10

Introduction

to

Modem Operation

,

(Comma) Pause.

The modem will

pause

for two seconds

(default time). It allows the modem

to wait

for

a

second dial

tone,

as,

for

example, when

waiting for an "outside line" on a PBX

board.

• '

a.

Example:

AT

D9,767-8900 <CR>

W

Meaning: Dial

9,

2 second pause,

dial

second

number.

Note; Multiple commas may

be

used to in-

crease

pause

time.

Wait for dial tone

before dialing.

Example:

AT

DTW767-8900 <CR>

Meaning: Wait

for a

dial

tone, then

dial the

number using tones. Note

that the W com-

mand MUST be

preceded

by

the D

command.

Note: This

command tells the modem to

wait

for 3 seconds

of continuous

dial tone before

beginning to

dial. The

W command

will return

a

result code

of

NO

DIALTONE if no dial

tone is found. The amount

of time the modem

waits

is

governed

by

the

S7

register. If the X2

or X4 commands

are used

in conjunction with

the W command,

the modem

will only wait

5

seconds

for

dial

tone

instead of S7

time. The

factory default

setting

of S7

is

30

seconds.

4-11

Chapter

4

Note

also

that

the

default

setting

of

the

X

command

does

NOT

tell

the

modem

to

wait

for

dial

tone.

See

the

X

command,

Section

5.18.

Wait

for

quiet

answer

before

dialing,

Example:

ATDT

5555555

@

12345

<CR>

Meaning:

Dial

the

number,

and,

after

the

phone

rings

at

least

once,

wait

for

5

seconds

of

silence.

When

5

seconds

of

silence

are

de-

tected,

dial

the

rest

of

the

number.

If

the

1200

bps internal

modem

does not

detect

5

seconds

of

silence,

the

modem

will

return

a

result

of NO

ANSWER

and

hang

up.

If

it

de-

tects

a busy

signal

the

modem

will

return

the

BUSY

result

code.

Note:

This

command

tells

the

modem

to

wait

for

one or

more

rings

followed

by 5

seconds

of

silence

before

continuing

the

command

string.

The

length

of time

the

modem

waits

is

speci-

fied

in

register

S7.

The factory

default

time

of

S7 is

30 seconds.

The

BUSY

result

code

will

be displayed

after

5

seconds

if

a busy

signal

is

detected.

This

command

is

used

to

access

a

system

that

does not

have

a dial

tone.

4-12

Introduction to Modem Operation

Hook Flash

Example:

AT D767-8900! <CR>

T

P

Meaning: Dial

a

number, hang

up

for half

a

second.

Note: The hookflash

tells the modem to

hang

up

for

a

half

a second.

It

is like

holding

the

button

on

your phone down for

a

moment.

This command may

be used to

transfer a call,

for example.

Touch-Tone Dialing

Pulse Dialing

Example:

AT

DP9,T 767-8900

<CR>

Meaning:

Dial

9

using pulse

(rotary) dialing,

pause

for

two

seconds, dial the rest of the

number using touch-tone.

Note:

When the modem

is turned

on, it

de-

faults to Pulse dialing. The P and T com-

mands specify which

type

of

dialing to

use.

The modem will then always default to the last

method

used. If you

were

to

enter AT

D767-8900<CR> immediately after the previ-

ous

example,

the modem would automatically

dial using touch

tone, which was the last

method used.

4-13

Chapter

4

;

(Semicolon)

Returns

modem

to

command

mode

after

dial-

ing.

Note:

This

command

is

used

to return

the

mo

dem

to the

command

state

at

the

end of

dial-

ing

a number.

It

basically

serves

the

same

function

as an

escape

code

(+++)

but

can

be

used

automatically

at the

end of

a

command.

This

feature

may

come

in

handy

when

you

wish

to

call a

timesharing

service

which

will

require

you

to dial

additional

digits

once

you

connect.

You

will

continue

to hear

the

call

being

made

as in

normal

operation.

Example:

AT D

767-8900

:<CR>

Meaning:

Dial the

phone

number

and

return

for

command.

R

Reverse

Mode.

Used to

call

an

"originate

only"

modem

such

as an

acoustic

coupler.

:

n

1 1

mi- i

fT i-r TiTifr 1 1 r

1 1

i r r ii rn- 11- 1 r n i r !

;

T-,•i-i:i f r i r 1

1

- ^i n i , r

,

>

--,

, v,

.'

,.

,>,

,

,,;'.-,

^^V^.";,'....-. ^^

]]

.

.-:

. .

. . . ;

:•'

.:-:

f

-\

Example:

AT

DP9,T767~8900R<CR>

Meaning:

Go into originate

mode,

dial

the

first

number

using

pulse

dialing,

pause,

dial the

second

number

using

touch

tone,

reverse

into

answer

mode

so that

the modem

will

"answer"

the

originate

only

modem.

Note:

The

R

command is

always

placed

at the

end

of a string

of

commands.

4-14

Introduction

to

Modem Operation

Auto-Dialing

for

Voice

Calls

The

modem may

be used to

automatically dial

a

number

for

you

with

the D command.

You would

enter

a

number,

listen

for

the

ring, pick

up

the phone,

press any key, which tells the modem

to

hang up. You

can

then

talk to

the person

on. the other end.

Example;

AT D 767-8900<CR>

If the phone line

is

busy, you

would then only have

to

enter A/

to

redial if

you

hear

a busy

signal-

Timing Parameters

The times assigned

to

the dialing sequences are controlled

by

reg-

isters

S6

through SI 1.

See

Chapter 6 for

a

complete

listing

of all

of the registers, functions and values.

4.7

Auto

Answer

Mode

The modem

is

set to

automatically answer calls. This

is

a

useful

feature when

you

wish

to access

your computer from a distant lo-

cation, for example.

The auto

answer function is contoLled

by

the

SO

register.

To disable the auto

answer function, enter the direct

command AT S0=0<CR>.

The

SO

register determines the number of rings the modem

will

wait before answering a call. The register may have values from

0-255.

Setting the register at tells the modem not to answer the

call at all.

4-15

Chapter

4

Examples:

ATSO=0<CR>

Modem

will

not

answer.

ATS0=1<CR>

Modem

will

answer

after

one

ring.

ATS0=5<CR>

Modem

will

answer

after

five

rings.

The new

value

will

be

in effect

until

a Z

(re-set)

command

is

given

or until

the

modem

is

turned

off.

At that

time,

the

SO regis-

ter

will

return

to the

default

value.

The

modem

will

wait

until

the

ring

number

in

register

SO is

reached

and

then

answer

the

phone

and

send

a signal

to the

other

modem.

The

1200

bps

internal

modem

then

waits

until

a

carrier

signal

is

received.

If

it is,

you

will see

a

CONNECT

result

code

on

your

screen

in

the

default

setting of

the

X

command,

X0.

If

no

carrier

is

detected

within

30 seconds

(default

time),

the

mo-

dem

will

return

a

NO

CARRIER

result

code

(again,

in

the

default

value

of

the X

command),

hang

up, and

return

to

the

command

state.

If

another

modem

calls

your

system,

when

auto-answer

is

dis-

abled,

you

will

receive

a RING

result

code

on

your

screen.

The

modem

will

not

answer.

If

you

are

not

set

up to

auto-answer,

and

the

phone is

ringing,

you

can

type AT

A

<CR>,

and

the

modem

will

answer.

(See

Section

5.1)

Timing

Parameters

As

with

the

dialing

commands,

the timing

parameters

associated

with

answering

are

controlled

in the

S

registers.

Registers

SO,

S7,

and

S9 control

the

functions.

See

Section

6.1

for

a

complete

list-

ing

of

the

registers,

functions

and

values.

4-16

Command Summary

Chapter

5

COMMAND

SUMMARY

The

following is a summary

of all of the modem

commands in al-

phabetical order with

examples. For each command a

parameter

table is provided stating

the default

values

(those

established when

the modem is turned on

or reset). Recall that a value of is as-

sumed when no

parameter is entered.

Command examples

follow

the

description.

5.1 A

-

Answer

Immediately

Default

Parameter

Parameter

Command Value Range

Description

A

—

—

—

Sending an A

command

to

the

modem tells it

to

answer

immedi-

ately without waiting

for a

ring.

It then will wait for a

Carrier Sig-

nal. It could also be

used, for

instance, if the RING

result code

appears on the screen

when the

modem is not

set

for auto

answer.

Once

the A

command is executed, no other

commands can be

entered.

i

Example:

AT

A<CR>

There are no

parameters

associated with this

command. When it is

entered,

the

modem immediately goes

off-hook

(without waiting

5-1

Chapter

5

for

a ring)

and

"listens"

for

the

Carrier

signal.

The

default time

is

30

seconds

(use the

S7=

command

to

change

this value).

5.2 A/

-

Repeat

Last

Command

Default

Parameter

Parameter

Command

Value

Range

Description

A/

A/

This

command

will

repeat

the last

command

line.

It

is

most

useful

when

used

to re-dial

the last

number

dialed.

;.;.;

'""

""

ttttiiiimmttmtmmmiiimmmimiMiiiiit^^

Example:

A/

This

command

differs

from

all

the

others

in

two ways:

*

It

is

not

preceded

by AT.

*

No CARRIAGE

RETURN

is

entered.

5-2

Command

Summary

5.3 C

-

Carrier

Signal

Control

Default

Parameter

Parameter

Command Value

Range

Description

C

CI

0-1

0=transmitter

off

l=transmitter on

The C

command allows

manual control

of the modem's

carrier

signal. The carrier is the

high pitched

whistle

you

hear when call-

ing a

modem. In the CI

state (the default)

the

carrier signal

set

by

the

modem

automatically goes on and

off as

required.

That is,

Carrier

is on:

*

after

dialing

a

number results in a

connection.

*

after

an A

command detects a

Carrier from the

other end.

At all other times,

the Carrier

signal is not

output. If

CO

is en-

tered, the

Carrier signal is never

output. This is

handy

when using

the modem to

dial

voice

calls.

i i i

:

i -nn ii-f^—

i iii i —i^-i—«*r n n

ii i i h i —y^f*^*.h

i in i ii h i i h i 1

1

Example:

AT

C0<CR>

This command

prevents the modem

from

outputting

the

carrier

signal. To change

this condition, the

CI or Z

command

must

be

entered. Be

very careful

in using the CO

command. If

entered

while communicating

with Telenet,

Tymnet,

or some

other

net-

work,

the network

will disconnect you.

5-3

Chapter

5

5.4 D

-

Dialing

Command

Command

D

Default

Parameter

Parameter

Value

Range

Description

—

Sn^dialing

sub-

commands

Nn=telephone

numbers

The D

command

allows

the

user

not

only

to

dial

a

number

but

adjust

dialing

to

the

local

telephone

conditions

as

well.

The

set

of

sub-commands

include:

,

Pause

for

dial

tone

T

Touch

tone

dialing

P

Pulse

(rotary)

dialing

R

Reverse

mode

;

Return

to

Command

Line

after

Carrier

detected

! Hookflash

W

Wait

for

dial

tone

@

Wait

for

5 second

quiet

answer

Examples

of

the

use of

the

Dialing

command

and

subcommands

are

provided

in

Section

4.

7.

5-4

Command Summary

5.5 E

-

Echo Back Control

Default

Parameter Parameter

Command Value Range Description

E El

0-1

0=do not echo in

command

mode

l=echo characters

in

command mode

Whether

or not

keystrokes are echoed back to the screen when

the modem is in the Command State is determined

by

the

E com-

mand. The default setting

(El)

displays

all

characters

on

the

screen.

The EO command should

be

used when the modem

is

connected

to a

terminal in half-duplex. The reason for this

is

that

if the terminal is in half-duplex, both it and the modem will echo

the character

on the screen

resulting in double printing.

To

pre-

vent this, turn the modem's echo off

(AT E0<CR>). The echo

feature

is only

activated in the Command State, that is, when

you

are entering commands to the modem.

It

is not activated

when

data

is

transmitted

to

a

remote

system. Some communications soft-

ware also requires that character echoing be suppressed.

5.6 F

-

Set Communications

Mode

Default Parameter

Parameter

Command Value

Range Description

F

Fl

0-1

0=half-duplex

l=full-duplex

The communication mode is normally set to

full duplex, which is

the default setting of

your modem. This command

is available pri-

5-5

Chapter

5

marily

for

compatibility

with

some

software,

which

may not

provide

an

echo.

You

should

not

have

to change

this

setting.

Both

your

computer

and

modem

are set

for

either

full

or

half

du-

plex.

In

half-duplex,

the

modem

will

echo

back

characters;

in

full

duplex,

it

will not.

If

either the

modem

or the

computer

is set

for

half

duplex,

the

characters

you enter

will

echo on

your

computer

screen.

If both

are

set at

half

duplex,

double

characters

will

ap-

pear on

your

screen

since

both the

modem

and

the

computer

are

echoing

characters.

Change

the

modem

to full

duplex. If

both

the

computer

and

the

modem

are

set for

full

duplex,

no

characters

will

appear

on the

screen.

Change

the

modem

to half

duplex

to

see the

characters

you enter

echoed

on

the

screen.

:;!

|*Hiirit

;

iitiffitftit^

Example:

AT F0<CR>

This

command will

cause

the

modem to

echo

back

characters

be-

ing

transmitted

onto

the

screen.

5.7

H

-

Hook

Control

Command

H

Default

Value

Parameter

Range

0-1

Parameter

Description

0=On

hook

(hang

up)

l=Off

hook

The

H

command

replicates

the

action of

picking

up the

handset

on

a telephone.

That is,

when

you

remove

a telephone's

handset

5-6

Command

Summary

from the

cradle,

you go

off-hook

(a

dial tone is heard); when

you

replace it in the

cradle,

you go

on-hook (drop the connection). In

normal

operation

only the HO command is used

to go

on hook

(terminate the

call).

Going

off hook is automatic

when

the Dialing

command is entered.

1

Example:

AT

H<CR>

This command assumes

that the user has temporarily suspended

the On-line

State to enter the Command

State by

entering the

Escape

Code

(+++).

After the CARRIAGE

RETURN <CR> is en-

tered, the Carrier

Signal is terminated and the connection

put on-

hook. Notice

that no

parameter

was entered in

this example;

hence,

a

entry

is assumed.

5.8 M

-

Monitor Speaker Control

Default Parameter Parameter

Command

Value

Range Description

M

Ml

0-2

0=Speaker off

l=On until carrier.

2=Speaker

always

on.

The computer's speaker can

be

used to listen in on

a

call in proc-

ess. For

instance, the default setting (Ml) sends all

tones (e.g.,

dial tone,

busy, ringing)

up to

the point the carrier is received.

Once the carrier is received, the speaker is automatically turned

off. Alternately, the MO command can be entered to keep the

5-7

Chapter

5

speaker

off

all of

the time

or the

M2

command

entered

to

send

all

signals,

including

the

Carrier

Signal,

to the

speaker.

Note that

the

M2

command

can

be used as

a form

of trouble-

shooting.

If

unanticipated

call

terminations

occur frequently,

enter

M2

and listen

to the

Carrier

signal.

If it

changes

tone

or

stops, the

modem

will

drop

the

connection.

In

this

case, the

phone

lines

are

faulty

or the

modem

at the

other

end

is

malfunctioning.

"

f

' """

n ii i h i i ii i niiiiiiin , .,

'

.v,,

,•',

v

---,-:,-•,•;,:;.

:,.

;..::..

..:.

: ::...;;.>;

f

Example:

AT M<CR>

This

command

is

used

to turn

off the

speaker

so that no

signals

are

sent

to

the

speaker.

Notice

that no

parameter is

entered

so

that

is

assumed.

5.9

-

Return

to On-line

State/Initiate

or Exit

RDL

Default

Parameter

Parameter

Command Value

Range

Description

O

OO

0-2

0=Return

to on line

state.

1-Exit

RDL and

return

on-line

2=Initiate

RDL and

return

on-line.

This

command

is generally

used

to return

to

the On-Line

State

after

an Escape

Code

(+++)

has

been entered

to

exit to

the

Com-

mand

State,

as

in

the following

example.

5-1

Example:

Command Summary

Enter:

+ +

+

Result:

OK

AT

MO 0<CR>

CONNECT

Note:
Returns

modem

to local

command state.

Turns

the speaker off

and

returns

on line.

Two specialized

versions

of the command, Ol

and

02,

are

used

to

exit and

initiate Remote

Digital Loopback.

These two

commands

are

used

ONLY

when

entering or exiting RDL. Consult

Chapter

3

of

this manual

for information

on how to perform these

tests.

5.10

P

-

Pulse

Dialing

Command

P

Default

Value

Parameter

Range

Parameter

Description

Before

a Dial is

attempted,

the

modem

must

be told whether pulse

(rotary)

dialing

or touch tone dialing methods

should

be used.

This

command

sets the modem

so that all numbers

output

by

sub-

sequent

dialing commands

use

the

pulse

dialing

method

until told

otherwise.

^^^^^^???!T'-!-!

'!*!"

T'-^^^^^^^W!

!!

!

!!!!

!!! V.

'-!•'

'-'

'

.'.M.'.M.

'

M.^M!*"*'""!'!™!'!'!'"!'!'!^

Example:

AT DP767-8900<CR>

5-9

Chapter

5

This is

the

only

form

of this

command-

There

are no

parameters

associated

with

it.

5.11

Q

-

Quiet

Mode

(Result

Code)

Control

Default

Parameter

Parameter

Command

Value

Range

Description

QO

0-1

0=Result

codes

sent

l=Result

codes

not sent

Whether

or not

the Result

codes

are returned

is

set

with

this

com-

mand.

For

example,

the

command Ql

would

be

used when

you

are using

the

modem with

a receive-only

printer.

This

command

would

prevent

the

result

codes from

being printed

out.

5.12

R

-

Reverse

Mode

Default

Parameter

Parameter

Command

Value

Range

Description

R

This

command

is

used

at the

end of

a command

to put the 1200

bps

internal

modem

into

answer mode

when trying

to

establish

contact

with

an originate-only

modem.

.

f*********^**«****«^**^****^*^>^^

"'"Tii'ii i'lii'ii

''""'"

, '

''

''" ''

Example:

AT D

767-8900R<CR>

5-10

Command Summary

The

modem is

instructed

to

dial

the number

and then enter

an-

swer mode.

5.13 Sr?

-

Determine

Status

of

a

Register

Default

Parameter

Parameter

Command

Value

Range

Description

Sr? 0-16

"r" in this command

specifies one

of the

modem's

registers.

This

command allows

the user

to display the

contents of the

regis-

ter specified

in the

command. These registers

set

certain

opera-

tional

characteristics. All

of the

characteristics

have a default

value

set when the

modem is turned

on or reset.

However,

they

can

be

changed

(see the next command)

if needed. For a

description

of

the registers

and examples

of

the

Sr? command, see

the

"Set

Command"

(Section

6.7).

5.14 Sr=n

-

Change

Register Value

Default

Parameter

Parameter

Command Value

Range

Description

Sr=n

—

0-16

for "r" (register

number)

0-255

for

"n" (value

in

register)

As

mentioned previously,

certain modem operations

are controlled

by

the contents of the registers. When the

modem

is turned

on or

5-11

Chapter

5

reset,

a default

value is

set

for

each

of

these registers.

This

value

can

be changed,

however,

using

the

ATSr=n<CR>

command.

A

description

of

the registers

and

examples

of the

Set

Command

are

provided in

the heading

"Set

Command,"

Chapter

6.

5.15 T

-

Touch

Tone

Dialing

Default

Parameter

Parameter

Command

Value

Range

Description

Before

a Dial

is

attempted,

the

modem

must

be

told

whether

pulse

(rotary)

dialing

or touch

tone dialing

methods

should

be used.

This

command

sets the

modem

so that

all

numbers

output

by sub-

sequent dialing

commands

use the

touch

tone dialing

method

until

told

otherwise.

E!?m!?!?v^??!?S!?!5!?

:

!

:

:

!

;

! :i: !

:

! v!yi"v !

-
!

'

! ! !

!

! ! ! !

'.[

\l

l

M'.-'. ! !

•!

! !

^!

\-

l.l

.-

\ i-

l

J. l\

M

,

. h

!.!-i^^MI-l-l.

|

J-!.

|

-

l

-

|

AL

|

.'J.MM','.M.'.'J.',l

''

.'.

i

J

i. i .i. i

.j.

i.m ,i.

u i .-.J.

i

.i.i.'l'.'

m'ffl

Example:

AT

DT767~8900<CR>

This

is the

only

form of

this command.

There

are no

parameters

associated

with

it.

5-12

Command Summary

5.16

V

-

Result

Code

Control

Default Parameter Parameter

Command

Value

Range Description

V VI

0-1

0=Result

numbers

displayed

1= Result words

displayed

In

the default

mode, all

result codes are displayed as English

words. Alternatively,

the V0 command can be

entered

to render

numbers instead of words.

See Section

4.5 for an explanation of

the

words and their corresponding numbers along with the

mean-

ing of

each. Recall that

words are

recommended

when the results

are

to be

interpreted

by

a user and numbers should

be used

when

the results are interpreted

by

a program.

"??WWTW!f'Wf^?WfWW""7!f"Tr»ffl

,

!Wr^

Example:

AT

V0<CR>

Enter this command from the Command State before turning

over

control of the modem from the user

to a

program.

5-13

Chapter

5

5.17

W

-

Wait

for

Dial

Tone

Default

Parameter

Parameter

Command

Value

Range

Description

W

The

W

command

instructs

the

modem

to wait

for

a dial

tone

be-

fore

dialing.

It

must

be entered

AFTER

the

dial

(D)

command.

Example:

AT DT

W

767-8900<CR>

This

command

tells

the

modem

to

wait for

a

dial

tone

before

dial-

ing

the

number,

using

touch

tone.

(See

Section 4,7

for

more

infor-

mation

on the

W

command.)

5.18

X

-

Extended

Result

Code

Set

Default

Parameter

Parameter

Command

Value

Range

Description

X

XO

0-4

See following

table.

The

X

command

allows

you to

select the

set

of

desired

result

codes.

See

Section

4.5

for

a further

explanation

of

these

codes.

5-14

Command Summary

Code

XO XI X2

X3 X4

OK

*

1

CONNECT

*

2

RING

*

3 NO CARRIER

*

4

ERROR

4

5 CONNECT 1200

-

6 NO DIALTONE

7 BUSY

8

NO

ANSWER

* * *

* * *

* * *

* * *

* *

*

* * *

*

_

*

* *

Notes:

1)

Most software

written

for the

"AT"

modem command set does

not accept the extended

result codes

(5

through 10), so the de-

fault XO is used.

2)

The NO

ANSWER result code is returned

only when the mo-

dem

is using the

@

command.

See

Section

4.7.

3)

The BUSY and

NO

DIALTONE

result

codes

will

be

displayed

after 5 seconds instead

of after 30 seconds

(default of S7).

5-15

Chapter

5

5.19 Z

-

Modem

Reset

Default

Parameter

Parameter

Command

Value

Range

Description

The Z

command

resets

the modem.

There

are

several results

when

the

modem

is reset.

*

any

call-in-progress is

terminated.

*

all commands

are reset

to

the

default

values.

*

all

commands

after

the Z command

in a

command

line

are NOT

executed.

'•t*iL+iZ*iZhjLujjjjjjjjJL^^

;-;•; ',"•

;

;;;;;;;;;:;;::•;; :; ;•;;:-:

'vi

:

i

:

::

-;

;:;;:;:;

>:-;

:::; ;;-;;-:-;-:-:

:-:-;

;-::-;

;

;-; ;-;-;-;•; ;-:

:

:

::--::

:':

:::::::

:

:

:

:

:-:

:

:::

:v:

:::

:

:

:

:

ftoSJ

Example:

AT

Z<CR>

This is

the

only form

of this command.

There

are no parameters

associated with

it.

5-16

Modem Registers

Chapter

6

MODEM REGISTERS

6.1 The

Set Command

There are two

Set command

forms:

ATSr?<CR>

ATSr=n<CR>

The first

reveals

the contents of

the register indicated

by

"r." The

second changes the contents of "r"

to

the value specified

by

"n."

These registers are dedicated memory locations within the 1200

bps internal modem's memory space that control certain opera-

tions. Every time the modem is turned on or reset (with the

Z

command), the default values are set. This means

that if

changes

are required to one or more registers

to

ensure proper operations,

they must

be

made each

time

the modem is

turned

on.

The following table

lists the

registers

and

summarizes

their effect

upon operation.

Register Range

Unit Default

50

0-255

rings

1

51

0-255

rings

52

0-127

ASCII 43

Description

Ring to answer

on

Number of

rings

passed

Escape code character

6-1

Chapter

6

S3

0-127

ASCII

13

S10

1-255

1/10

sec.

7

Sll

50-255

millisec.

70

S12

0-255

1/50

sec.

50

S13

bit

mapped

S14

bit

mapped

S15

bit

mapped

S16

0-1

S17

Not used

S18

Not

used

Command

terminator

(Carriage

return

charac-

ter)

S4 0-127

ASCII

10

Line

feed

character

S5

0-127

ASCII

8

Back

space

character

S6

2-255

seconds

2

Wait

time

for

dial

tone

S7

0-255

seconds

30

Wait

time

for

Carrier

S8 0-255

seconds

2

Pause

time

S9

1-255

1/10 sec.

6

Carrier

detector

response

Hang

up delay

after

loss

of

Carrier

Touch

tone

duration,

spacing

Escape

code

time

UART

status

register

Option

register

Flag

register

Test

Modes

6.2 Reading

and

Changing

Registers

To find

out

what

the

current

setting

of a

register

is,

you

use the

Sr?

command.

The

modem

will

respond with

the

decimal

value

of

6-2

Modem Registers

the current value in the register. Several registers

may be

checked

at

one time. For

example if

you

wanted to check

what

ring the

modem is set to answer on (Register

SO)

and how long the modem

will wait for

a

dial tone (Register

36),

you would enter:

AT SO? S6? <CR>

If the registers are set at default values, the response

would be;

001 The

modem

is

set

to

answer

after one ring.

002

The modem waits

two

seconds for

a

dial tone.

OK

End of sequence.

To change the value in these registers,

you

would

use the Sr=n

command. Using the same registers as the previous example,

you

would enter:

AT S0=4<CR> (Change the value in Register

SO

to

4; mo-

dem will answer on ring

4.)

OK (Command acknowledged

by

modem.)

AT S6=3

<CR> (Change

the value

in

Register

S6

to

3;

mo-

dem will wait three seconds for dial tone.)

OK (Command acknowledged

by modem)

The next section describes each register

in

greater detail.

6.3 Register

SO

-

Auto

Answer

To Display Modem To Change

Status, Enter: Displays: Status, Enter:

AT SO? <CR> or

1 AT

S0=n

<CR>

n=0-255

6-3

Chapter

6

Whether

or

not the

modem

is

set for

auto-answer

is

determined

by

this

register.

A value

of

turns

the

modem

into

an

originate

only

device-

A

value

of 1-255

sets the

modem to

answer

a

call on

the

"nth"

ring.

6,4

Register

S1

-

Rings

Passed

To

Display

Status

, Enter:

Modem

Displays:

To

Change

Status,

Enter:

AT

SI?

<CR>

The

SI

register

counts

the

number

of

times

the

phone

rings.

This

register

is

cleared

after

8 seconds

have

passed

without

a ring.

Note

that

there

is no

need to

change

the

value

of

this

register.

(The

Sl=n

command

can

be

used,

however.)

6.5

Register

S2

-

Escape

Code

ASCII

Value

To

Display

Modem

To

Change

Status,

Enter:

Displays:

Status,

Enter:

AT

S2?

<CR>

43

AT

S2=n<CR>

(+)

(n=0-127)

The

default

value

of this

register,

43, sets

the

Escape

Code to

be

the

"+"

character,

but it

can

be

changed

to any

ASCII

character

6-4

Modem Registers

of the user's

choosing. The

value for "n" MUST be

a legitimate

ASCII

character

within the range of

0-127.

Setting "n" out of this

range

disables the Escape Code.

Recall the

sequence of steps necessary

to

effect an escape from

the

On-line

State

to

the Command State:

1)

Wait 1 second (see register SI 2 to change)

2)

Enter

escape

character three times

(e.g.,

+++)

3)

Wait

1 second (see register

S12 to

change)

Notice that both the Escape Character

AND the

Guard Time (the

time period in steps 1 and

3)

can be

redefined.

6.6 Register

S3

-

Command Terminator

ASCII

Value

To Display Modem To Change

Status,

Enter: Displays:

Status,

Enter:

AT S3?

<CR> 13

AT S3=n

<CR>

(n=0-127)

The default

value of this

register

is 13,

which

is the

ASCII charac-

ter for carriage return. There should

be

no need

to

change this

value

unless

another special character better suits the user's needs.

6-5

Chapter

6

6.7

Register

S4

-

Line

Feed

ASCII

Value

To Display

Modem

To

Change

Status,

Enter:

Displays:

Status,

Enter:

AT

S4?

<CR>

10

AT

S4=n

<CR>

(n=0-127)

The

line

feed

character

is

used only

in

the verbal

result

mode

(VI)

after

a carriage

return.

Change

this value

toanull

only if

you do not

want

or

need

a line

feed

at this time.

6.8

Register

S5

-

Back

Space

ASCII

Value

To

Display

Modem

To

Change

Status,

Enter:

Displays:

Status,

Enter:

AT

S5?

<CR>

8

(Do

not change)

(n=0-127)

The

S5

register

defines

the

character

that

is

echoed

when

the

back

space

key is

pressed.

This

value is

not normally

changed.

6.9

Register

S6

-

Wait

for Dial

Tone

Time

Period

To

Display

Modem

To Change

Status,

Enter:

Displays:

Status,

Enter:

AT

S6?

<CR>

2

AT

S6=n

<CR>

seconds

(n=2-255)

6-6

Modem Registers

The S6 register

sets the amount of time

the modem waits between

going

off

hook and

dialing

the number. The modem

will

accept

a

minimum

of

a

2 second delay. (In fact,

even

if this

register is

set

to

1,

the modem still

waits for 2 seconds.)

If

outward dialing repeatedly

fails (result code 3 or NO CAR-

RIER), it

may be

because a

dial tone

is not rendered

to

the

mo-

dem

by

the phone company before

dialing begins. In this case,

increase

the

value

of the

S6

register until

a satisfactory delay is

established. Note

that

rt

n" is

a

value expressed

in seconds.

6.10 Register

S7

-

Wait for

Carrier

Time

Period

To Display

Modem To Change

Status, Enter:

Displays:

Status, Enter:

AT S7?

<CR>

30

AT S7=n

<CR>

(seconds)

(n=0-255)

S7

sets the number of seconds the

modem waits for the carrier

signal after

a

number

has been dialed. This value can

be de-

creased if the modem

at the other end is particularly fast

at re-

sponding.

A minimum figure of 10 for numbers within

your

area

code

and 20 for numbers which require

a

different area

code

is

recommended.

6-7

Chapter

6

6.11

Register

S8

-

Pause

Time

of

Comma

To Display

Modem

To

Change

Status,

Enter:

Displays:

Status,

Enter:

AT

S8?

<CR>

2

AT S8=n

<CR>

seconds

(n=0-255)

How long

the

modem

delays

for

an

intermediate

dial

tone

is

set by

the

S8 register.

(Recall

that a

comma

is used

in

the dialing

com-

mand

to allow

for

a

second

dial tone,

used

with

many PBX's.)

Note

that the

modem

does

not actually

"listen"

for the

intermedi-

ate dial

tone

(unless

you

use the

W

command)

; it

just delays

for

a

period

and

assumes

that

the

tone is

present.

Consequently,

if

a

3

or NO

CARRIER

result

code

is

rendered

frequently,

try

increasing

the

value

of

S8. Note

that

the value

of the

registers

is an expres-

sion

of

seconds.

6.12

Register

S9

-

Carrier

Signal

Detect

Time

To

Display

Modem

To

Change

Status,

Enter:

Displays:

Status, Enter:

AT

S9?

<CR>

6

AT

S9=n

<CR>

(600

msec.)

(n=0~255)

Do not

confuse

the

purpose

of this

register

with

that of

S7

-

Wait

for

Carrier.

Register

S9 determines how

long the

carrier

signal

6-8

Modem

Registers

must

remain

active after

dialing

before it is

recognized

as valid. In

other

words,

noise

from the

phone line

(voices and

interference)

can

occasionally have

the

same frequency

as the carrier

signal.

To

safeguard

against

misinterpretation

of

noise

as

carrier,

the

value of

S9 sets a time

window

during which

the signal

must

sustain the

proper carrier

frequency.

It is highly

unlikely

that

any

noise

can sustain

the frequency

asso-

ciated

with

the carrier

signal for

600 milliseconds,

the

default

value.

Increasing

this value

further

decreases

the likelihood.

We

recommend

against changing

this

value

to a shorter

period, how-

ever.

Note that

the value

in register

S9

is

a value expressed

in

1/10

seconds.

For

instance,

a value

of

6.0

=

,6

seconds

or

600 milliseconds

10.0 =

1.0 second

or 1000

milliseconds

24.0

=

2.4

seconds or 2400

milliseconds

Also

note that

the

value

of

S9

has no

effect

upon the time

be-

tween when

loss

of carrier

occurs

and when the

modem

goes on

hook

(hangs

up). The

value in the

S10 register

determines

this

time

window.

6.13 Register

S10

-

Carrier Loss

to

Disconnect

Delay Time

To Display

Modem

To Change

Status, Enter:

Displays:

Status, Enter:

AT S10?

<CR>

007

ATS10=n<CR>

(700

msec.)

(n-1-255)

6-9

Chapter

6

When

the carrier signal

from

the other end

goes

away,

it

is the

modem's

cue to terminate

the

connection.

In areas

with poor

quality

telephone lines,

the carrier

signal

can occasionally

drop

out

and

cause unintentional

disconnects.

Setting register

S10

for

the

default

values

allows for

occasional lapses

in the carrier

signal.

The actual

time window

for carrier

dropout is NOT

determined

by

the

contents

of the

S10

register.

Instead, this

period is

a function

of

the

following

formula:

S10

-

S9

=

window

(700

msec

-

600 msec.

=

100 msec or .1

seconds)

When

telephone lines

are

poor, the

value of

S10 can be increased

if

disconnects are

frequent. The

adverse effect

of this

command

is

that

some

"garbage" characters

may appear

on the screen

if the

time

is too long.

Every increment

increases the length

of time

by

1/10

seconds

(100

milliseconds).

Note that

a value of 255

tells the

modem

to consider the

carrier signal always

present.

6.14 Register

S11

-

Speed Control for

Touch

Tone

Dialing

To Display

Modem

To

Change

Status, Enter:

Displays:

Status, Enter:

AT

Sll? <CR>

70

Do not change

(msec.) (n=0-255)

The Sll

default setting

establishes

a touch tone dialing rate

of

around

7 digits per second

(DPS). This register should

not

be

changed.

Note that it

has no effect on the

pulse dialing rate.

6-10

Modem Registers

6,15

Register S12

-

Escape Code

Guard Time

To Display Modem To Change

Status, Enter: Displays: Status, Enter:

AT

S12? <CR>

50

AT S12=n

(1

second) (n=0-255)

Recall

that there are

two

wait periods that surround the entry of

the special

Escape Character (see

the description of

S2 for a

re-

view). The length

of

time

the

user

must wait is set

in register

S12.

Each increment adds 1/50

seconds

(20

milliseconds)

to

the delay.

Consider 50

as

the minimum and increment only in value of

50's

(1

second).

NOTE: A value of is certainly possible in this register.

In this

case,

entering three Escape characters without any

surrounding time buffers effects an immediate exit from

the On-line State. Be careful if this option

is selected

to

define an Escape Character that is unlikely to occur in

batches of

three

during data

entry while

the user is on-

line.

6.16

S1 3

-

S1 5 Status

Registers

The value

of these

registers can

be

read with the Sr? command.

DO NOT use the Sr=n command to alter their contents.

6-11

Chapter

6

Registers

S13,

S14, and

S15 can

be used for program

review

of

modem

status. The information

is

rendered in

byte form

with

each

bit being defined

as follows.

S13 UART

Status

Bit

Value

Description

-

not

used

*

1

1

Extended

Result

Codes

disable

Extended

Result

Codes Set

2

1

Parity

Disabled

Parity Enabled

3

1

Odd Parity

Even

Parity

4

1

7

Data

Bits/word

8

Data

bits/word

5

-

not

used

*

6

1

Buffer

overflow

flag (causes

ERROR

result code

to

be sent)

7

8th data

bit

set to space (if bit

4=1)

1

8th data bit

set to mark

(if bit

4=1)

*

unused

bits may

be or 1

at

random

6-12

Modem

Registers

S14

-

Option

Register

Bit

Value Description

Auto Answer

disabled

1

Auto

Answer

enabled

1

Local Echo Disabled

1

Local Echo

Enabled

2

Result Codes

Enabled

1

Result

Codes

Disabled

3

Result

Codes as

Numbers

1

Result Codes as

Words (See

Vn

command)

4

Undefined

-

may be 1

or

5

Pulse dial

1 Tone

dial

6

1

Speaker enabled

until carrier

detected.

7

1

Speaker

enabled always.

Note:

Both bits 6 and 7 must be

zero

to

disable speaker.

6-13

Chapter

6

SI

5

-

Flag

Register

Bit

1

2

3

Value

1

1

Description

Same

as bit 4

Same

as bit

5

Answer

Originate

Half

duplex

Full

duplex

Bits

4

and

5

define

the

bps rate

as shown

in

the

following

table:

Bit

4

1

1

Bit

5

1

1

Bps

Rate

110

300

1200

7

Carrier

Off

Carrier

On

undefined

S16

-

Test

Mode

Bit

Value

Description

1

Local

Analog

Loopback

disabled

Local

Analog

Loopback

enabled

1-7

Not

Used

6-14

Modem Registers

6.17

Programming

Suggestions

and

Considerations

The most important function of a modem control program is al-

ways to know

whether the modem is in the Command or On-line

State. If the program ever gets confused, data passed

from com-

puter

to

modem may

be

construed

as a

command and vice versa.

To avoid the consequences that

could result

from this

confusion

please make note of the following suggestions:

1. Send commands to the modem

only when it is in the Com-

mand

State.

2.

Commands entered when the modem is in the On-line State

are considered data and

will

be output as

such. Be sure

to

en-

ter the Escape

Code

before entering commands.

3. Data output

by

the computer when the modem is in the On-

line

State

is interpreted as data. Be sure to

enter

AT O <CR>

to

re-enter

the

On-line

State

after

a

temporary exit to the

Command state.

4. Do not have the computer echo command

results (either

word

or number) to the modem. This

would qualify

as

random data.

6.18 Command

Executions

Some commands execute

in

as

little

as

250 milliseconds (the Dial-

ing command being

a

notable exception).

For the computer to

"catch" the

result

code,

be

sure

it

is

prepared to do so

within this

time

constraint.

6-15

Chapter

6

When

under

program

control,

we

recommend

using

the

result

code

numbers

instead

of

the

English

words.

Toward

the

beginning

of

the

program,

input

the

command

AT

V0<CR>

to

the

modem.

It

is

usually

easier

for

a

program

to

interpret

a

single

character

than

a

series.

The

modem

can

only

perform

one

command

line

at

a time.

Wait

for

the

result

code

before

sending

another

command.

6.19

Escape

Code

Precaution

In

some

contexts,

it

may be

desirable

to

disable

the

Escape

Code;

e.g.,

when

the

modem

is in

answer

mode

while

attached

to

a

com-

puter

operating

in

half

duplex.

The

reason

for

this is

that

if

the

distant

computer

should

inadvertently

send

the

Escape

Code

as

part of

its

message,

the

modem

would

revert

to the

Command

State

when

the

string

is

echoed

by

the

computer.

All

subsequent

data will

be

construed

as

commands

with

unpredictable

results.

NOTE:

To

disable

the

Escape

Code,

define

the

Escape

Character

in

register

S2

as

a

non-ASCII

(i.e.,

greater

than

127)

value.

6-16

Appendix

Appendix

A

ASCII CODE CHART

This

table is a list of each of

the standard ASCII control

charac-

ters. The list shows the character, and the hex and decimal value

of the character.

Decimal

Value

00
01

02
03
04

05

06

07
08

09

10

11

12
13
14
15
16
17

18
19

20
21

22

23

24

25

26

App-l

Keyboard

Character

Hex

Value

A

@

00

A

A

01

*B 02

A

C

03

A

D 04

A

E

05

-p

06

A

G

07

A

H

08

A

I 09

A

J 0A

A

K

0B

A

L

OC

A

M 0D

A

N 0E

"O OF

A

P 10

A

Q

11

A

R

12

A

S

13

"T

14

A

U

15

-v

16

A

W 17

A

X 18

A

Y

19

A

Z 1A

Appendix

Keyboard

Hex

Decimal

Character

Value

Value

A

[

IB

27

^

1C

28

A

]

ID

29

IE

30

IF

31

space

20

32

I

21

33

22

34

#

23

35

$

24

36

%

25

37

&

26

38

27

38

(

28

40

)

29

41

2A

42

+

2B

43

2C

44

2D

45

2E

46

'

2F

47

30

48

1

31

49

2

32

50

3

33

51

4

34

52

5

35

53

6

36

54

7

37

55

8

38

56

9

39

57

^

3A

58

J 3B

59

<

3C

60

3D

61

>

3E

62

App-2

Keyboard

Character

Hex

Value

? 3F

@

40

A

41

B 42

C 43

D

44

E 45

F

46

G 47
H

48

I 49

J

4A

K 4B

L

4C

M 4D

N

4E

O 4F

P

50

Q

51

R 52

S

53

T

54

U 55

V

56

w 57

X 58

Y

59

Z 5A

[

SB

\ 5C

]

5D

*

5E

-

5F

<

60

Appendix

Decimal

Value

63

64

65

66
67

68

69

70

71

72

73

74

75

76
77
78

79

80
81

82

83

84

85
86

87

88

89

90

91

92
93

94
95

96

App-3

Appendix

Keyboard

Character

Hex

Value

a

61

b

62

c

63

d

64

e

65

f

66

g

67

h

68

i

69

J

6A

k

SB

1

6C

m

6D

n

6E

6F

P

70

q

71

r

72

s

73

t

74

u

75

V

76

w

77

X

78

y

79

z

7A

{

7B

1

7C

}

7D

-

7E

rub

7F

Decimal

Value

97

98
99

100

101

102

103
104
105
106
107

108
109

110

111

112

113
114

115
116
117

118

119

120
121
122
123
124

125

126

127

App-4

Appendix

Appendix

B

TECHNICAL

INFORMATION

Telephone

Line Information:

FCC Registration

Number: AU692V25-3510

Ringer

Equivalence:

0.4B

Telephone Line

Interconnect Cable:

RJ1IC

Permissive Cable

TELEPHONE

PIN

NUMBER

JACK

POSITION NO.

MODEM

JACK

3

4

5

1

TIP

RING

RJ11C

PLUG

3

4

5

2

Specifications

Modem

Compatibility

Dialer

Compatibility:

Modem

Data Rate

Speed

Selection:

Originate

Mode;

Answer Mode:

Bell

212A at 1200,

300

baud;

Bell

103,

113 at 300

baud

Industry standard

"AT"

command

set

1200,

300

and 110 baud

Automatic on

attention

character

Automatically set to

speed

of in-

coming call

App-5

Appendix

Operating

Modes:

Test

Modes:

Automatic

dialing,

manual

dial

(with

telephone),

automatic

an-

swer,

manual

answer,

automatic

dial

with

switch

to voice

mode.

Analog

(local)

loopback;

remote

digital

loopback

(both

initiate

and

respond).

Software

command

con-

trolled.

Receiver

Sensitivity

-45

dBm

Transmit

Level

-10

dBm

Tone

Dial

Level:

dBm

Line

Impedance

600 Ohms

Ringer

Equivalence:

0.4B

Modulation:

300

baud:

Frequency

Shift

Keyed

(FSK)

1200

baud:

Differential

phase

shift

keyed

(DPSK)

Power

Consumption:

Off

Line

On

Line

+5V

+12V

-12V

44.92

ma

56.

6$ ma

44.0

ma

44.0

ma

21.56 ma

21.56

ma

Data

Format

Dialing:

Pulse:

Tone:

8

bit, no

parity;

7 bit

even,

odd,

mark

or

space

parity

(rotary)

lOpps.

Including

*

and

#, duration

70 ms

(adjustable)

App-6

Appendix

Command

Buffer;

40

characters

Speaker:

Normally

on

during

dialing;

can be

turned

off

by

command.

Technology:

Low

power CMOS

circuitry utilizes

proprietary

LSI

modem circuits,

8051

microprocessor.

Control pro-

gram: 4K

bytes.

App-7

ADDENDUM

A

To

AH

Those

Using

a

Multi-Line

Key

System:

The

Tandy

1200

bps

modem

has

a mini

jumper

marked

"Wl".

When

this

mini

jumper

is on,

A/Al

are

active.

A/Al

are

used

to

turn

on "in

use"

lights

on

many

key

systems.

The

mini

jumper

is

shipped

in the

"off"

position

to

avoid

possible

problems

if

you

have

two

separate

telephone

lines

at

your

home

(or

office)

.

The

telephone

company

frequently

wires

the

second

of

the

two

lines

to

the

same

leads

as

A/Al

(pins

2, 5

or RJ11).

When

the

jumper

is

on,

you

may

experience

problems

with

the

second

line

when

using

the

modem

on the

first line.

Add-l

INDEX

A Command,

5-1

A/

Command

(Repeat Dialing),

5-2

Answer Immediately Command, see

A

Command

Answer Mode Test,

3-2

ASCII Code Chart, App-1

Auto Answer,

2-4,

4-15

Carrier Signal Control,

5-3

Changing of

States,

4-2

C Command,

5-3

Command

Executions,

6-15

Command

Results, 4-5,

5-13

Command

State,

4-2

Command

Syntax,

4-4

Commands, line limits,

4-4

Communications

Mode,

5-5

D

Command,

4-9,

5-4

Dialing Basics,

4-9

Dialing Command,

4-9,

5-4

Subcommands

,4-

10

Duplex,

5-5

E Command,

5-4

Escape

Code,

4-2

Precautions,

6-16

Examples,

Dialing,

4-9

F Command,

5-5

FCC

Requirements,

2-1

Functional States,

4-1

H

Command,

5-6

Hanging up,

5-6

How to

change

states,

4-2

Installation, Chapter 2

Local

Analog Loopback Test,

3-1

M Command,

5-7

Model Number,

2-1

Modem Command

Descriptions, Chapter 5

Modem Status Registers,

Chapter

6

O

Command,

5-8

On line

state, 5-8,

4-2

Originate Mode

Test,

3-1

Pulse Dialing,

4-13,

5-4

Q

Command,

5-10

R Command,

4-14,

5-10

Reading and Changing

Registers,

6-2

Registration, FCC,

2-1

Remote

Testing, Chapter

3

Registers

(Auto

Answer),

6-3

1 (Rings Passed),

6-4

2

(Escape Code),

6-4

3 (Line

Terminator),

6-5

4 (Line Feed),

6-6

5

(Back Space),

6-6

6

(Wait for Dial Tone),

6-6

7

(Wait for Carrier),

6-7

8

(Pause

Time

of

Comma),

6-8

9

(Carrier

Signal Detect Time),

6-8

10 (Disconnect

Delay),

6-9

11 (Dialing Speed),

6-10

12

(Guard

Time),

6-11

13 (UART

Status),

6-12

JU

14

(Options Register),

6-13

15 (Flag

Register),

6-14

16

(Test Modes),

6-14

Repeat Dial,

5-2

Reset

Modem,

5-16

Result

Codes,

4-5, 5-13

Result Code

Control,

see

Q

command, V

command

Return to On line, see

O command

Reverse Mode,

5-10

Ringer Equivalence,

2-1

Set

Command,

6-1

Speaker Control,

5-7

Speed,

4-8

Status Registers,

see registers

Sr? Command,

5-11

Sr=n

Command,

5-11

System Reset,

5-15

Testing, Chapter

3

Touch Tone Dialing,

4-13,

5-12

Transmission

Speed,

4-7

V

Command,

5-13

Verbal Results,

4-6

W Command,

4-11,

5-14

X Command,

5-14

Z Command,

5-16

RADIO

SHACK, A

DIVISION

OF TANDY CORPORATION

U.S.A.: FORT

WORTH, TEXAS 76102

CANADA:

BARRIE, ONTARIO

L4M 4W5

TANDY CORPORATION

AUSTRALIA

91 KURRAJONG

AVENUE

MOUNT DRUITT.

NSW 2770

BELGIUM

PARC INDUSTRIEL

5140NANINNE (NAMUR)

BILSTON ROAD

WEDNESBURY

WEST

MIDLANDS WS10 7JN

rinted

in

U.S.A.