Black Box Tote-a-Fax 542 User manual

CUSTOMER
SUPPORT
INFORMATION
Order toll-free in the U.S. 24 hours, 7 A.M. Monday to midnight Friday: 877-877-BBOX
FREE technical support, 24 hours a day, 7 days a week: Call 724-746-5500 or fax [phone]
Mail order: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
Web site: www.blackbox.com • E-mail: [email protected]
MARCH 1992
FX119A
Tote-a-Fax 542
TOTE-A-FAX
DATA SPEED
FAX SPEED
CARRIER DETECT
LOW BATTERY

1
CHAPTER 4: OperationTOTE-A-FAX 542
Tote-A-Fax 542
Installation and Operation Manual
FCC REQUIREMENTS
This equipment complies with FCC Rules Part 68. Located on the equipment is the FCC
Registration Number and Ringer Equivalence Number (REN). You must provide this
information to the telephone company if requested.
The Registration Number and REN will be inscribed on the printed circuit board on insert cards
or on a label affixed to the chassis bottom. The FCC requires these numbers be prominently
displayed on an outside surface of the device.
The REN is used to determine the number of devices you may legally connect to your
telephone line. In most areas, the sum of the REN of all devices connected to one line must not
exceed five (5.0). Contact your telephone company to determine the maximum REN for your
calling area.
The telephone company may change technical operations or procedures; these changes may
affect your equipment. You will be notified of changes in advance; this will give you the
necessary time to make arrangements to maintain uninterrupted telephone service.
If you experience trouble with this telephone equipment, contact your dealer for information
regarding service or repairs. The telephone company may ask that you disconnect this
equipment from the network until the problem has been resolved. I f your equipment continues
to disrupt the network, the telephone company may temporarily disconnect service. If this
happens, you will be informed of your right to file a complaint with the FCC.
The equipment may not be used on coin service provided by the telephone company.
Connection to party lines is subject to state tariffs.
WARNING!
This equipment generates and uses radio frequency energy. If not installed and used in
accordance with the manufacturer’s instructions, it could cause interference to radio and
television reception. It has been type tested and complies with the limits for a Class B
computing device in accordance with the specifications in Part 15 of the FCC Rules designed to
provide reasonable protection against interference in a residential installation. there is no
guarantee that interference will not occur. If this equipment causes interference to radio or
television, as determined by turning the equipment off and on, the user is encouraged to correct
the interference with the following measures:
• Reorient the receiving antenna.
• Relocate the computer with respect to the receiver.
• Plug the computer into a different outlet so the computer and receiver are on different
branch circuits.
Changes or modifications to this unit not expressly approved by the party responsible for
compliance could void the user’s authority to operate the equipment.
SHIELDED CABLES
This product has been tested and complies with FCC limits for a Class B computing device.
Using unshielded cables could cause your system to emit excess radio frequency increasing
the change of interference. To comply with FCC regulations, it is necessary to use shielded
DTE cables with your installation.

2
TOTE-A-FAX 542
TABLE OF CONTENTS
CHAPTER PAGE
1. Specifications ......................................................................... 3
2. Introduction ............................................................................. 4
2.1 Description ......................................................................... 4
2.2 Features/Benefits ............................................................... 4
2.3 System Requirements ....................................................... 6
3. Installation ............................................................................... 7
4. Operation ................................................................................. 8
4.1 The Basics of Modem Operation ....................................... 8
4.2 Giving Commands to the Modem ...................................... 8
4.3 The AT Command Set for the Tote-A-Fax 542 ................. 10
4.4 S-Registers for the Tote-A-Fax 542 .................................. 14
4.5 Fax Command Set for the Tote-A-Fax 542 ....................... 21
4.6 Result Codes Table for the Data Modem ......................... 25
4.7 Data Compression and Error Detection for the Modem .... 26
5. Troubleshooting ................................................................... 29

3
CHAPTER 1: Specifications
FACSIMILE MODEM
Standards — CCITT V.29/Group III, V.27 ter, V.21 sync
Speed — 9600-, 7200-, 4800-bps
Operation — Half-duplex
Interface — EIA RS-232/CCITT V.24
Certification — FCC Part 68
Transmit Level — 0 to –15 dBm
Receive Level — 0 to –43 dBm
Audio — Provided through built-in speaker
DATA MODEM
Standards — CCITT V.21, V.22, V.22 bis, Bell 103, Bell 211A
Data compression — CCITT V.42, V.42 bis, MNP Level 5
Speed — 2400-, 1200-, 300-bps
Operation — Full-duplex
Interface — EIA RS-232/CCITT V.24
Memory — Built-in non-volatile memory; EEPROM for configuration storage
GENERAL SPECIFICATIONS
System Requirements — DOS 2.1 or higher, 640K RAM
Ringer Equivalency — 0.4 B (Canadian Load Number: 41 B)
Connectors — (1) DB25 female; (2) RJ-11 telephone interface jacks
Power — 115 VAC± 10%; 60 Hz, or 9-volt battery, 200 mA
Size — 0.8"H x 2.2"W x 4"D (2 x 5.6 x 10.2 cm)
Weight — Shipping weight: 3.5 oz. (.001 kg) (not including optional Power
Supply PS 427)
1. SPECIFICATIONS

4
TOTE-A-FAX 542
2.1 DESCRIPTION
The Tote-A-Fax 542 (FX119A) is a
compact, battery-powered, portable
9600-bps Group III fax and 2400-bps
Hayes®compatible data modem. The
data modem supports today’s most
popular and powerful data
compression and error correction
protocols: CCITT V.42, V.42 bis,
and MNP®Level 5.
The Tote-A-Fax 542 is ideal for
portable, laptop, and notebook PC
users. It is perfect for travelers who
use portable PCs and need a way to
send files from remote locations to
the office mainframe, LAN server,
PC, and/or fax machine.
The Tote-A-Fax 542 is one of our
growing line of ultra-compact
products (modems, line drivers,
muxes) that provide you with full
datacomm support and the conven-
ience of a small enclosure. Like the
Tote-A-Fax (FX112A), it is one of the
smallest fax modems in the world. It
is compatible with all DOS-based
PCs, Windows 3.0, and the Apple
Macintosh®.
With the Tote-A-Fax 542 you can
gather data while “in the field”.
Then connect the Tote-A-Fax 542 to
a telephone (in a hotel room, at
your remote office, an airport, etc.)
and to your portable PC; now you’re
ready to send files anywhere.
2.2 FEATURES/BENEFITS
2.2.1 F AX MODEM FEATURES
•Compatible with virtually all
portable PCs and with any Group
III fax.
The Tote-A-Fax 542 is compati-
ble with CCITT V.29 recom-
mendations for Group III fax
transmissions. Send and receive
faxes from your
portable/laptop/notebook PC
(DOS, Windows, or Macintosh
systems) to fax machines any-
where at speeds up to 9600 bps.
•Integrated fax and data
communications software.
The integrated fax/data
communications software loads
in just a few minutes to your
portable PC. The software is easy
to use and gives you all of the
functions and options to
compile files, merge many files
into one file, and send any fax or
data file. You can even customize
a cover sheet for transmissions.
2. INTRODUCTION

5
CHAPTER 2: Introduction
•Background Send and Receive
functions.
The Tote-A-Fax 542 sends and
receives fax files in background
mode. You continue to work
while your fax transmissions go
to their destination; you
continue to work while incoming
faxes arrive at your
laptop/portable PC. The Tote-A-
Fax 542 doesn’t tie you down or
hold you back from your other
tasks. The end result: you send
and receive your faxes without
wasting time or being distracted
from current work in other
applications.
•Print fax files directly to a
printer.
The Tote-A-Fax 542 will print
your received fax files to your
local Epson dot matrix printer
or Hewlett-Packard LaserJet
II/III laser printer (or
compatible printers). HGA,
CGA, EGA, and VGA mono- and
color-modes are supported, too.
You can make those incoming
faxes jump through a few other
hoops, too: they can be flipped,
compressed, or expanded for
better viewing, and they can be
displayed or printed either
automatically or on demand.
•Schedule fax transmission to
save money.
The Tote-A-Fax 542 lets you
schedule your fax transmissions.
This means you can send files at
some time in the future so that
you can take advantage of lower
telephone rates. You save money
in telephone line connect
charges. Plus the Tote-A-Fax 542
provides an activity log to
monitor and manage your
incoming and outgoing fax calls;
print the activity log to add to
your business account ledger.
•Transmit a fax to a single remote
fax or to any number of fax
machines.
The Tote-A-Fax lets you do a
traditional fax transmission
(point A to point B) and it gives
you the ability to broadcast a fax
file to a group of fax machines.
This would be very helpful to
travellers who need to get the
same information out to a
number of people in different
places.

6
TOTE-A-FAX 542
•Hayes AT Command Set
compatibility.
You can issue any of the Hayes
AT Commands to the Tote-A-Fax
542 for easy control of the
modem’s operations: you don’t
have to learn a new proprietary
communications “language” to
use this fax/data modem.
•Built-in non-volatile memory
supplied by EEPROM for
storing configuration.
•Automatic power down of the
unit for extended life of battery.
Don’t worry if you forget to turn
off the Tote-A-Fax 542—it knows
when to go to sleep to conserve
its battery power.
2.3 System Requirements
• IBM®PC/AT®or compatible
computer with at least 640K
RAM and a hard disk drive with
a minimum of 5MB of available
disk space; or
• Apple Macintosh®
• EGA/CGA/VGA/HGA adapter
and monitor.
• Direct outside telephone line.
• Printer (optional)
2.2.2 D ATA M ODEM F EATURES
•V.42, V.42 bis, and MNP5 data
compression/error correction
protocol support.
Double or even quadruple your
effective data throughput rate
(from 2400 bps to 4800 bps,
7200 bps, or even 9600 bps). The
Tote-A-Fax 542 will
communicate with other V.42,
V.42bis, and MNP compatible
modems to get your data files to
their destination in less time—
with total accuracy. This saves
you costly telephone connect
time charges and valuable time
while you are on business.
•Compatible with five of the most
popular transmission standards:
CCITT V.21, V.22, V.22 bis,
V.23, Bell 103, and Bell 212A.
The Tote-A-Fax 542 modem can
communicate with most any
modem in the world. This wide
range of standards support is
invaluable to anyone who has to
send files to different modems
on a regular basis. You can send
your files at any of the following
three base speeds: 2400 bps,
1200 bps, 300 bps.

7
7
CHAPTER 3: Installation
Follow these steps to connect the
Tote-A-Fax 542 to your computer:
1. Attach the 110V Power Supply
unit (PS427) to the PWR
connector on the Tote-A-Fax
542. DO NOT PLUG THE POWER
ADAPTER INTO A POWER OUTLET AT
THIS TIME. Wait until step #4 to
apply power to the modem.*
2. Connect the RS-232 connector
on the Tote-A-Fax 542 to the RS-
232 port on your personal
computer.
3. Connect one end of the supplied
RJ-11 telephone cable to the
LINE jack on the Tote-A-Fax
542. Connect the other end of
this cable to the telephone line
jack.
4. Plug the Power Supply unit into
a power outlet.*
Here is a listing of the indicators
(LEDs) on the front panel of the on
the Tote-A-Fax 542:
PWR............Power
AA ...............Auto Answer
SD ...............Send Data
RD ...............Receive Data
*You can also operate the Tote-A-
Fax 542 with batteries rather than
using the Power Supply unit.
3. INSTALLATION

8
TOTE-A-FAX 542
4.1 The Basics of Modem Operation
After you’ve connected your Tote-A-
Fax 542 modem to your personal
computer, you need to establish a
procedure to communicate
(exchange data) with a data modem
in another location.
You now have the hardware
connected: on your end you have
the Tote-A-Fax 542 modem linked to
your PC; on the other (remote) end
there should be a modem attached
to another PC. Each modem is
attached to a telephone line.
A telephone call can be placed
between the two modems over the
telephone line. Once the modems
establish a connection, they need a
common set of parameters (rules
and limits) to exchange data bits.
This is the data communications
protocol.
4.2 Giving Commands to a Modem
Finally, you need a way to “talk” to
your modem through your
computer. You can use the:
• command code for the modem;
learning code is a difficult and
time consuming task.
• Standard AT Command Set to
issue commands to the modem.
The Standard AT Command Set is a
simplified “modem language”
supported by a majority of today’s
modems. It consists of short
groupings of keyboard characters,
followed by a carriage return or
enter key. Each character or
character group represents a
command or series of commands.
Pressing the return key initiates the
command you’ve stated to the
modem. This method of telling your
modem to do certain functions is
quick, simple, and easier to use than
command code.
The Tote-A-Fax 542’s built-in
command set is very compatible with
the Standard AT Command Set. It is
an asynchronous commu-nication
program that you can learn with
little effort. It will let you take
control of your modem through
your PC’s keyboard. The commands
are short, simple, and fast.
4.0 OPERATION

9
CHAPTER 4: Operation
4.2.1 T HE AT C OMMAND
Each command in the Standard AT
Command Set is preceded by the
two-character sequence AT. AT is
short for “Attention!”. You control
and command the modem by first
demanding its “attention” and then
dictating your command. When you
press the return or enter key you
officially initiate the command.
Each AT Command consists of the
following elements:
1. The two-character attention
sequence AT
2. A command
3. A command parameter
4. Press the return key
NOTE: There are two exceptions to this
convention: the A/ and the +++
commands. Both commands are
discussed later in this manual.
A command is not initiated until you
press the carriage return key <CR>.
The modm ignores entries
represented as spaces (that is, if you
press the space bar on your keyboard
the modem does not acknowledge
these characters as part of the
commad).
4.2.2 AT C OMMAND P ARAMETERS
Not all commands have command
parameters associated with them. If
a parameter is missing from an AT
command statement, the value of
zero is assigned to it. Sometimes
zero is actually a valid command
parameter.
Summary: The sequence of
characters that follow the AT
sequence constitute the core of the
command. They cause the modem
to enter a command state.
Command parameters give the
modem further details about the
command. Pressing the carriage
return key initiates the command
(that is, the modem goes to work).
If you key in AT without a command,
you are simply sending a “wakeup
call” to the modem, telling it to get
ready to listen to a command.
The modem queues commands in a
40-character command line. The
command line beginning with AT
can have several commands.
NOTE: It is not necessary to have a
separator between the commands.
Here is the command line format:
AT command <parameter>command<parameter>
<CR>
The carriage return <CR> termin-
ates the command line. When the
modem receives the <CR> the
commands are performed in the
order in which they are sent to the
modem. If more than 40 characters
are sent to the modem an error
occurs; all commands must then be
retentered.
4.3 The AT Command Set for the
Data Modem
The following table gives the AT
commands supported by Tote-A-Fax
542 modem, including a description
of each command, its command
“range” and size. Pertinent notes
are included within the table.

10
TOTE-A-FAX 542
COMMAND DESCRIPTION/RANGE —SIZE
A/ Execute previous command, without pressing <CR> key
AT Attention
ATA Answer immediately
ATB0 CCITT V.22 mode
ATB1 Bell 212A mode (default)
ATDP Dial using Pulse Dial
ATD Dial command
ATDT Dial using DTMF Tone Dial Default
ATDL Dial using last number, regardless of last command
Note: The following eight modifiers will dial using the previously used technique (pulse or
tone), or the Tor Pcommand can be added after the D(Dial) command.
ATDW Wait for Dial tone for period set by S7 register
ATD@ Quiet answer: wait for 5 seconds of silence before dialing
ATD! Hookflash: commonly used in PBX systems
ATDR Reverse answer mode
ATDSnDial stored number n=0–3
ATD/ Wait 0.125 seconds
ATD; Return to command mode after dialing
ATD, Pause for amount of time set in Register S8
ATE0 Command echo disabled
ATE1 Command mode echo enabled (default)
ATF0 No echo when connected
ATF1 Echo transmitted characters when connected (default)
ATH0 Go on hook (open relay)
ATH1 Go off hook (close relay)

11
CHAPTER 4: Operation
COMMAND DESCRIPTION/RANGE —SIZE
ATI0 Identification Code
ATI1 Identification Code
ATI2 “OK” response if checksum verifies
ATI3 Revision number
ATL0 Lowest volume setting
ATL1 Same as ATL0
ATL2 Medium volume setting (default)
ATL3 Maximum volume setting
ATM0 Speaker always off
ATM1 Speaker on until carrier is detected (default)
ATM2 Speaker always on
ATM3 DTMF Tones are not heard, but speaker is on until carrier detected
AT0 Originate immediate or return to data mode
ATQ0 Enable result code (default)
ATQ1 Disable result code
ATSn? Provide S Register Value (n=0—27)
ATSn= Set register value (n=0—27)
ATV1 Verbose response (default). See ATV0 for response.
ATW0 Negotiation process result codes not returned (default)
ATW1 Negotiation process result codes returned
ATX0 Enable result codes 0—4
ATX1 Enable result codes 0—5
ATX2 Enable result codes 0—6
ATX3 Enable result codes 0—5, 7, and 10
ATX4 Enable result codes 0—10 (default)
ATY0 Disable long space disconnect (default)
ATY1 Enable long space disconnect
ATZ0 Software reset, restore S Register from Profile Location 0
ATZ1 Restore S Register
AT&C0 EIA carrier line always forced on (default)
AT&D0 DTR always on (default)
AT&D1 Modem goes to command mode when DTR goes Off

12
TOTE-A-FAX 542
COMMAND DESCRIPTION/RANGE —SIZE
AT&D2 Modem goes On Hook and return to command mode when DTR
goes Off
AT&D3 Modem initializes when DTR goes OFF
AT&F Fetch S Register from EPROM for factory default
AT&G0 No guard tone (default)
AT&G1 500 Hz guard tone enabled
AT&G2 1800 Hz guard tone enabled
AT&J0 RJ-11 select (default)
AT&J1 No function
AT&L0 Switched line select (default)
AT&L1 Leased line select (not supported)
AT&M0 ASynchronouse mode (default)
AT&P0 US Make/Break Ratio for Pulse dialing (default)
AT&P1 UK Make/Break Ratio for Pulse dialing
AT&Q0 Same as AT&M0
AT&R0 Clear to Send (CTS) follows RTS (default)
AT&R1 CTS always On
AT&S0 Data Set Ready (DSR) always On (default)
AT&S1 DSR normal
AT&T0 Terminate test in progress (default)
AT&T1 Initiate local analog loopback for time set by register S18
AT&T2 Not defined
AT&T3 Initiate digital loopback for time set by register
AT&T4 Enable remote digital loopback (RDLB) response
AT&T5 Disable remote digital loopback (RDLB) response
AT&T6 Initiate RDLB
AT&T7 Initiate RDLB with Self Test
AT&T8 Initiate ALB with Self Test
AT&W0 Write S Registers into User Profile Number 0
AT&W1 Write S Registers into User Profile Number 1
AT&X0 Modem provides transmit clock
AT&X1 DTE supplies transmit clock
AT&X2 Slave clock mode (not supported)

13
CHAPTER 4: Operation
COMMAND DESCRIPTION/RANGE —SIZE
AT&Y0 Power up recall User Profile 0
AT&V List configuration both active and stored
AT&7m=An Store telephone numbers into NVRAM (XL93C46) where:
mis the Number Location (0—3)
Ais P or T (Pulse or Tone)
nis the telephone number

14
TOTE-A-FAX 542
4.4 S-Registers for the Data Modem
4.4.1 W HAT IS AN S-R EGISTER ?
A modem holds vital information
about modem configuration and
operation in internal memory
locations called Status (S-) Registers.
Each S-Register is assigned a number
from 0 to 27, and each contains 8
data bits (or, one byte of
information). In some S-Registers
each bit has a different function;
these are termed bit-mapped S-
Registers. The bits are numbered
0—7, with 0 the least significant bit.
Other S-Registers use the total
number of bits (8) to represent a
single value.
One of the functions of an S-Register
is to store modem configuration
information. Thus, commands
which change or alter the
configuration operate by modifying
the corresponding S-Register.
Most S-Registers have a fixed,
predefined meaning to the modem,
and can be read or altered. Others
are read only registers; if you try to
change that particular register, the
modem responds with an error
message. Still other registers are
either destined not to be used or are
reserved for future options for the
modem. A reserved register cannot
be read or changed.
4.4.2 B IT -M APPED S-R EGISTERS
Bit-mapped S-Registers contain
configuration information for more
than one option or modem
function. Each bit is mapped to a
different modem function.
Sometimes a group of bits within a
particular register are mapped to a
function.
4.4.3 D IFFERENT S-R EGISTER S ETS AND
T HEIR P URPOSES
The Tote-A-Fax 542 modem uses
three different sets of S-Register
values to do its various functions and
options. You can alter (modify)
some registers but not others.
Here is a summary of the three types
of S-Reigsters:
• Active (Current) Configuration
S-Registers
These are the S-Register values
that the modem uses to operate.
When you “read from” or “write
to” an S-Register, you are
working with an active (current)
configuration S-Register.

15
CHAPTER 4: Operation
• Stored Configuration S-Registers
Stored configuration S-Registers
are kept in nonvolatile memory;
the register values are stored in a
semiconductor random access
memory (RAM) chip that retains
the informa-tion even when the
modem loses power. So if the
modem’s batteries wear down,
the power adapter is unplugged,
or the power outlet fails, the
stored configuation S-Registers
remember their contents.
When the modem powers up it
loads the current S-Register
configuration with the stored
configuration.
Use the AT commands discussed
at the beginning of this chapter
to store your current
configuration to the stored
configuation, or to load the
current configuration with the
stored configuration.
• Factory Configuration S-
Registers
These registers are factory-set
choices for the modem; they
form a “default” configuration.
These values are permanently
stored in a “read only memory”
(ROM) semiconductor chip.

16
TOTE-A-FAX 542
This configuration can be used to reset your S-Registers with known
default values—a home-base for the modem to return to should you want
to reset your modem configuration.
4.4.4 S-R EGISTER N UMBERS AND THE R EGISTER F UNCTIONS
The table on the following pages lists all 27 S-Register numbers and includes
a description of each register’s function.
Refer to the Software User’s Manual for instuctions on how to change the
S-Registers for the Tote-A-Fax 542 modem.
S-Registers for the Data Modem

17
CHAPTER 4: Operation
REGISTER
NUMBER REGISTER FUNCTION
S0 Number of rings to answer: default = 0 (no answer) (stored)
S1 Ring count: Stores number of rings
S2 Escape code character; default = 043 (ASCII character is + )
S3 Carriage return charactere; default = 013
S4 Line feed character; default = 043 (ASCII character is + )
S5 Back space character; default = 003
S6 Wait for dial tone; default = 002 (seconds) (minimum setting)
S7 Wait for carrier after dial; default = 030 seconds
S8 Duration for delay after comma; default = 002 (seconds)
S9 Carrier detect response time; default = 0.6 (seconds)
S10 Lost carrier to hang up delay; default = 1.4 (seconds)
S11 Touch tone duration; default = 095 (milliseconds)
S12 Escape code guard time; default = 1 (seconds)
S13 Bit mapped register
S14 Bit mapped register: stored in nonvolatile RAM (XL93C46)
Bit 0 Reserved
Bit 1 Echo
Bit 2 Result codes
Bit 3 Numeric result codes
Bit 4 Always 0
Bit 5 Tone/Pulse dialing
Bit 6 Reserved
Bit 7 Answer/Originate
S15 Reserved
S16 Test Register
Bit 0 ALB
Bit 1 Reserved
Bit 2 Local Digital Loopback
Bit 3 Remote Digital Loopback

18
TOTE-A-FAX 542
REGISTER
NUMBER REGISTER FUNCTION
S16 Test Register (continued)
Bit 4 Initiate Remote Test
Bit 5 Initiate Remote Test with Self Test
Bit 6 Analog Loopback with Self Test
Bit 7 Reserved
S17 Reserved
S18 Test time stored in nonvolatile RAM (XL93C46);
default = 000 (seconds)
S19 Reserved
S20 Reserved
S21 Bit mapped register: stored in nonvolatile ROM (XL93C46)
READ ONLY MEMORY
Bit 0 0 = RJ11 Jack
Bit 1 Reserved
Bit 2 CTS/RTS Function
Bit 3 DTR Function
Bit 4 DTR Function
Bit 4 Bit 3 Function
0 0 DTR always true — default
0 1 DTR Off, forces command state
1 0 DTR Off, forces modem offline
1 1 Modem initializes with DTR Off (ATZ)
Bit 5 EIA carrier status
Bit 6 Guard tone select
Bit 7 Guard tone select
Bit 7 Bit 6 Function
0 0 No guard tone — default
0 1 550 Hz guard tone
1 0 1800 Hz guard tone
1 1 Reserved

19
CHAPTER 4: Operation
REGISTER
NUMBER REGISTER FUNCTION
S22 Option bit mapped register
Bit 0 Determines speaker volume
Bit 1 Determines speaker volume
Bit 1 Bit 0 Function
0 0 Low speaker volume
0 1 Low speaker volume
1 0 Medium speaker volume — default
1 1 High speaker volume
Bit 2 Determines speaker status
Bit 3 Determines speaker status
Bit 3 Bit 2 Function
0 0 Speaker always off
0 1 On until carrier is detected — default
1 0 Speaker always on
1 1 Same as “01”, except off for dialing
Bits 4-6 Determines response messages
Bit 6 Bit 5 Bit 6 Function
000
Basic message set
100
Extended with connect 1200, connect 2400
101
Extended with “No dial tone”
110
Extended with “Busy”
111
Extended with all messages — default
Bit 7 Determines Off Hook/On Hook (Make/Break) Ratio for
Pulse dialing
Bit 7 Ration
0 39/61 (USA and Canada); default
1 33/67 (UK and Hong Kong)