Simpletech Communicator Reference guide

Communicator

V.34 Data/Fax Modem

Plug n’ Play PC Card

Reference Guide

(Document Part Number 61600-00005-003)

Outline of Guide By Chapter

1. Using AT Commands
Some Notes About AT Commands
Configuring the Modem

Sample Configuration
Sample Configuration
Sample Configuration

AT Commands

AT& Commands
AT% Commands
AT\ Commands
AT) Commands
AT* Commands
AT: Commands
AT- Commands
AT+ Commands

2. Fax and Voice Commands

3. Result Codes and Messages

4. S-Registers
Example: Writing to an S-Register
Bit-Mapped Options S-Registers
Example: Setting an S-Register
Example: Interpreting an S-Register
Alphanumeric List of S-Registers

1. Using AT Commands

Communications programs control your modem by issuing modem instructions
called AT commands. While it is usually easiest to let the communication
software handle the task of issuing AT commands, there may be occasions
when you will want to control a series of commands yourself. The information
that follows is included to allow you to tailor your modem for specific needs.

If you want to send AT commands to your modem directly, you must be running
a data communication program. (You cannot send AT commands from your
operating system prompt.) Once the communication program is started, you
must put it into terminal mode. Many programs do this automatically. Your
modem must also be in command mode (see Some Notes About AT Commands) to
accept AT command strings. To verify whether your modem is in the proper
mode, type AT <Enter>. If the modem responds with an OK message, you are all
set.

AT commands must:

1. Start with the command string AT

2. Contain one or more of the commands listed in this chapter

3. End with a carriage return (shown in this book as <Enter>).

The following notation conventions are used in this chapter:

• AT commands and messages are shown in italics, like so:

AT &F0 <Enter>.

• Factory default settings for commands are shown in bold. These settings are

in effect until you issue a command altering the setting. For instance, the
default setting for Bn is B1. To return the modem to its factory default
settings at any time, type AT &F0 <Enter>.

• S-registers affected by, or related to, particular AT commands are listed in

brackets at the end of the command descriptions. Similarly, the AT
commands that affect, or are related to, the contents of an S-register are
listed at the end of each S-register description.

Refer to Table 1-1 for a summary of the basic AT commands. Refer to AT
Commands for the complete list of AT commands.

Table 1-1. AT Command Summary

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AT Command prefix used to begin almost all commands.

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Commands preceded by AT and followed by <Enter>:
D Dial the following number using the default or previous method (tone

or pulse).

DT Dial the following number using tones.
DP Dial the following number using pulses.
DS= n Dial stored number n.
W Wait for dial tone before dialing.
H Hang up the phone.
O Go on-line (switch from command mode to data mode). Used to resume

interrupted communications when the remote modem is still on-line.

Sr? Read S-register r.
Sr=n Write value n to S-register r.
Zn Reset and recall saved profile n.
&Fn Recall factory configuration n.
&V Display current configuration and stored profiles.
&Wn Save current configuration as profile n.
&Zn=x Save x as stored telephone number n.

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Command not preceded by AT and not followed by <Enter>:
A/ Repeat the previous command.

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Some Notes About AT Commands

• Some AT commands override other AT commands. For example, issuing AT

&K3 &K4 <Enter> will not enable both hardware flow control (&K3) and

software flow control (&K4), it will only enable software flow control. The
latter command overrides the former.

• If you do not specify a number on commands that end in a number, the

modem will take the number to be 0. So, for example, AT B and AT B0
achieve the same effect: setting communications to the CCITT standard. This
feature can be useful if you wish to save space when issuing commands.

• If your modem is on-line and you want to issue an AT command string to

your modem without disrupting your connection, you can bring your
modem into command mode by typing a special escape sequence. To issue
the escape sequence you must first not transmit any data for a period equal
to the guard time, which by default is one second. Then type +++ quickly. Do
NOT press <Enter>. Instead, wait for another second. The modem will respond
to this step with an OK message. Now your modem is ready to accept AT
command strings. When you want to resume your on-line connection, type
ATO <Enter>.

Configuring the Modem

By default, your modem is set up to automatically detect the appropriate line
speed, use hardware flow control, and connect using error correction and data
compression protocols, if possible. These settings are stored in read-only
memory (ROM) at the factory and can be recovered at any time by issuing the
&F0 command, described later in the chapter. If the factory settings do not
meet your needs, (say for instance, your software does not support hardware
flow control), you can define and store your own configurations into
nonvolatile memory using the &Wn command. You can then recover these
configurations at any time with the Zn command. Both &Wn and Zn are
described more fully later in the chapter.

These stored configurations are called profiles. Not all AT command settings
and S-registers can be stored as a part of a profile. The ones that can be stored
are so noted. Several sample modem configurations are shown below. These are
examples of profiles you might store in memory as your user-definable
profiles. You can store two user-defined profiles.

Sample Configuration 1

One useful configuration is obtained by typing AT &F0 &C1 &D2 &W0 <Enter>.
These commands have the following effect:

• &F0 restores the factory default configuration, turning on line speed

detection, hardware flow control, error correction, and data compression.
In other words, if the remote modem will allow it, your modem will use all
of its most advanced features.

• &C1 forces the carrier detect (CD) signal to follow the state of the carrier.

This allows your communications software to properly determine whether
the modem is on-line or off-line.

• &D2 instructs your modem to hang up when the data terminal ready (DTR)

signal drops. This will speed up the hang-up process for most
communications software packages.

• &W0 stores this configuration as profile 0. Now whenever you type ATZ

<Enter>, you will restore this profile.

NOTE: Since your modem will be using hardware flow control,

your communications software must also be set for hardware
flow control. In addition, to take advantage of the possible 4:1
data compression provided by V.42bis, you should set your
communications package to lock the DTE rate to the highest
speed possible: up to 115200 bps.

Sample Configuration 2

If you are using software that does not support hardware flow control, then
you might use the following configuration: AT &F0 &C1 &D2 &K4 <Enter>.

This configuration is identical to that of the previous example, except that &K4
is used to enable software flow control rather than hardware flow control.
Note that software flow control must be used with caution. Do NOT use software
flow control when you are transferring files that might naturally contain XON
and XOFF characters, such as binary files. Also, do not use software flow control
when you are transferring files using protocols like XMODEM or ZMODEM.

NOTE: If your modem is configured to use software flow control,
then you must also set your communications software to use
software flow control.

Sample Configuration 3

If your software does not support hardware flow control, but you would like to
transfer files with a protocol like XMODEM or ZMODEM, you should try
configuring your modem as follows: AT &F0 &C1 &D2 &K0 &Q0 \J1 <Enter>.

The first three commands are the same as described in the first example. &K0
turns off all flow control. &Q0 specifies a direct connection, which is a
connection without flow control, data compression, or error correction. \J1
forces the data terminal equipment (DTE) rate to match the data
communication equipment (DCE) rate, which is required when all flow control
is disabled. In this case, you must set your terminal speed to match the line
speed, e.g., 14.4 Kbps.

This configuration is not reliable for high-speed connections unless
transferring files with newer XMODEM or ZMODEM protocols: XMODEM and
ZMODEM protocols have error correction built into them. Also, to ensure that
file transfer is reliable, make sure that the protocol does not use packet sizes
that are too large.

AT Commands

This section lists the AT commands which the modem uses. This listing is
organized by the nonalphabetic first character after “AT” (i.e., no letter, &, %,
\, ), @, *, :, and -), and then in alphanumeric order. The default settings are
listed in bold.

A Answer Command. This command causes the modem to attempt to answer an

incoming call. The modem will make its attempt regardless of whether the
modem is in auto-answer mode or not. This command should be issued after
the RING result code is seen (when another modem is attempting to
connect).

A/ Re-executes the previous command line. This command is NOT preceded by

AT or followed by <Enter>.

Bn CCITT/Bell Setting. This command selects either the CCITT standard or the

Bell standard for 300 and 1200 bps communications. (See S27.)
B0 CCITT V.22 for 1200bps, CCITT V.21 for 300bps.

B1 BELL 212A FOR 1200BPS, BELL 103 FOR 300BPS.

C1 Carrier Control Command. This command is included for compatibility only

and performs no function other than to return an OK message.

Dn Dial Command. This command directs the modem to go off-hook, wait for a

dialtone, and dial the number indicated in the dial string, n. The dial string
may contain the characters 0-9 for pulse-mode dialing or 0-9, A-D, *, and #
for touch-tone dialing. Spaces, hyphens, and parentheses can be included
in the command to improve readability. For example, D [phone] and
D1234567890 are equivalent.

In addition, the dial string may contain these dial command modifiers:
L Redial the last valid number entered.
P Pulse-mode dialing. (See S14.)
T Touch-tone dialing. (See S14.)
S=n Dial 1 of 4 stored telephone number, where n is 0, 1, 2, or 3. (See &Zn)
W Wait for a dialtone. (See S7.)
, Pause before dialing the digits that follow. (See S8.)
@ Wait for quiet answer. Wait for one or more rings followed by at least

five seconds of silence before continuing with execution of the dial
string. This is useful for transferring calls on some PBX systems.

; Return the modem to command state. When placed at the end of the dial

string, this puts the modem into command mode. While in command
mode, the modem will not attempt to connect with the remote modem.

! Put the modem briefly on-hook. This can be useful for transferring

calls on some telephone systems. (See S29.)
^ Toggles calling tone for this call only.
J Perform MNP10 link negotiation at 1200 bps for this call only (see *H).
K Enable power level adjustment during MNP 10 link negotiation for this

call only (see “)Mn”).
& Wait for credit card bong before continuing with the dial string. If the

bong is not detected within the time specified in S7, the dial string will

be aborted, dialing terminated, and an error message generated.
R Accepted but causes no action.

En Local Echo Setting. This command determines whether the commands you

type are echoed to the screen. (See S14.)
E0 Disable command echo.

E1 ENABLE COMMAND ECHO.

NOTE: If you see duplicate characters, then both your modem
local echo and your application software local echo are enabled.

Fn Line Connection Speed Setting. This command is not supported in V.34

modems but reports OK for compatability. N0 or +MS, and S37 may be used to
force a particular connect mode.

Hn Hang-up Command.

H0 On-hook (hang up).
H1 Off-hook.

In Identification Command.

I0 Reports product code (e. g. 28800).
I1 Reports read-only memory (ROM) checksum. This number should

always remain the same.

I2 Reports OK.
I3 Reports ROM revision level and model.
I4 Reports modem identifier string.
I5 Reports country code (e.g. 022 for U.S.).
I6 Reports data pump model and code revision.
I7 Reports DAA code for external DAA (if not installed, reports 255)

LnSpeaker Volume Setting. (See also register S22.) On PCMCIA modems, there

may be no discernable difference between some volume levels.
L0 Off.
L1 Low.
L2 Medium.

L3 High.

Mn Speaker Control Setting. This command controls when the speaker will

be on or off. (See also S22.)
M0Always off.

M1 On during call establishment, off after receiving carrier.

M2Always on, even during data transmission.
M3On between dialing and carrier detection.

Nn Automatic Line Speed Detection Setting. (See also S31 and S37.)

N0 Automatic line speed detection disabled. Handshaking will be conducted

according to the contents of S37.

N1Automatic line speed detection enabled.

On On-line Command. This command switches the modem from command mode

to on-line mode. If there is no established connection, ERROR is returned.

O0 Go back on-line without a retrain.
O1 Go back on-line after initiating a retrain.

P Pulse-mode Dial Setting. This setting specifies pulse-mode dialing for all

subsequent connections. (See S14, contrast with T.)

Qn Result Code On/Off Setting. This command determines whether or not the

modem returns result codes such as OK, ERROR, or CONNECT. (See S14, S95,
Vn, Wn, Xn.)

Q0 Display result codes.

Q1 Do not display result codes.

Sn? Read S-register. This command enables you to read the S-register

specified by the number n. For example, typing ATS0? <Enter> will allow

you to view the contents of the S0 register.

Sn=x Write to an S-register. This command allows you to change the contents

of an S-register. For example ATS0=2 <Enter> writes the value 2 to the S0

register. Note: the modem does not perform error checking on values

written to S-registers. It will always return the OK message. (See S-

Registers for details on the contents of each S-register.)

T Touch-tone Dial Setting. This setting specifies touch-tone

dialing for all subsequent connections. (See S14, contrast with P.)

VnResult Code Format Setting. (See S14, S95, Qn, Wn, Xn.)

V0 Numeric result codes.

V1Verbose result codes.

Wn Connection Message Setting. If you change the value of S95, it may

override the Wn setting. (See S31, Vn, Qn.)
W0 Reports DTE rate only. For example:

CONNECT 57600
W1Reports DCE rate, error correction protocol, and DTE rate. For example:

CARRIER 28800

PROTOCOL: LAPM

CONNECT 57600
W2Reports DCE rate only. For example:

CONNECT 28800

Xn Extended Result Code Setting. This command selects which call progress

result codes are reported. (See S22, S95, Qn, Vn, Wn, and “Result Codes and

Messages.”)
X0 Send basic call progress result codes: OK, CONNECT, RING, NO CARRIER,

ERROR, NO ANSWER.

X1 Same as X0 but also report rate-specific CONNECT messages.
X2 Same as X1 but also report NO DIALTONE detection.
X3 Same as X2 but also report BUSY signal detection.

X4 Send all call progress messages.

YnLong Space Disconnect Setting. This command determines whether the

modem hangs up when it receives a long space signal (greater than 1.6
seconds) from the remote modem. If enabled, the modem will send a 4
second space signal to the remote modem before hanging up. (See S21.)

Y0 Disable long space disconnect.

Y1 Enable long space disconnect.

Zn Modem Reset/Restore Profile Command.

Z0 Perform modem reset and restore configuration profile 0.
Z1 Perform modem reset and restore configuration profile 1.

AT& Commands

&Cn Carrier Detect (CD) Signal Setting. (See S21.)

&C0 CD always on.

&C1 CD follows state of carrier.

&Dn Data Terminal Ready (DTR) Signal Setting. This command affects the

interpretation of the DTR signal. Note: when the modem is on-line, it

ignores a DTR drop that lasts less than the value in S25, .05 seconds by

default. (See S21.)

&D0 DTR is ignored.

&D1 DTR drop causes the modem to go into command mode.

&D2 Auto-answer is inhibited and a DTR drop causes the

modem to hang up.

&D3 DTR drop causes the modem to perform a soft reset.

&Fn Restore Factory Profile Command. This command will restore one of the

two preset factory profiles. These profiles enable automatic line speed

detection, hardware flow control, error correction, and data

compression. You can also define and store your own specialized

profiles. See the &Wn, &Yn, and Zn commands for details.

&Gn Guard Tone Setting. This command sets the guard tone for V.22 and

V.22bis connections. (See S23.)

&G0 No guard tone.

&G1 No guard tone.

&G2 1800 Hz guard tone. Used in the U.K. and some other

Commonwealth countries.

&Jn Telephone Jack Setting. The &J0 and &J1 commands are included for

compatibility only and perform no function other than to return an OK

message.

&Kn Flow Control Setting. If your communications software does not support

hardware flow control, you will need to specify &K0 or &K4 (see below).

(See S39.)

&K0 Disable flow control.

&K3 Enable hardware flow control only.

&K4 Enable software flow control only.

&K5 Enable transparent software flow control.

&K6 Enable both hardware and software flow control.

&L Leased Line Setting. The &L0 command is included for compatibility

only and performs no function other than to return an OK message. This

modem does not support leased line operation.

&M Selects a direct connection. This command is equivalent to &Q0.
&Pn Pulse Dial Make/Break Ratio Setting. Enabled on a per country basis (see

S28). If enabled the dial make/break ratio is as follows:

&P0 39%-61% dial ratio at 10 pulses per second.

&P1 33%-67% dial ratio at 10 pulses per second.

&P2 39%-61% dial ratio at 20 pulses per second.

&P3 33%-67% dial ratio at 20 pulses per second.

&Qn Asynchronous Mode Setting. (See S27 and S36.)

&Q0 Selects a direct connection.

&Q1 Reserved.

&Q2 Reserved.

&Q3 Reserved.

&Q4 Reserved.

&Q5 Selects a reliable connection. The value in S36 will

determine whether or not a failure to establish a
particular error correction link will result in the
modem hanging up or trying to make another type of

connection. (See also \N2, \N3, \N4, and \N5.)

&Q6 Selects normal connection. (Equivalent to \N0.)

&Rn Hardware Flow Control Setting. This command selects how the modem

controls its Clear to Send (CTS) signal if hardware flow control is

selected. (See S21.)

&R0 CTS always on.

&R1 CTS will drop only if required by flow control.

&Sn Data Set Ready (DSR) Signal Setting. (See S21.)

&S0 DSR always on.

&S1 DSR is active after an answer tone has been detected and

inactive after the carrier has been lost. Very few
communications packages require this setting.

&Tn Diagnostic Test Commands. This set of commands provides diagnostic

tests that comply with the CCITT V.54 recommendations. All connections

established during testing must be normal or direct connections. (See

\N0, +Q0, S16, S181.)

&T0 Terminate test in progress. Generally during a test the modem is

on-line. Therefore to issue this command you will need to type
the escape sequence +++ and wait for the OK message. You can
then type AT&T0 <Enter> to terminate the test. Alternatively, if S18
is non-zero, a test will terminate automatically after the number
of seconds specified in S18.

&T1 Local analog loopback test. This test checks the operation of your

modem’s transmitter and receiver.
For example:

1. Your modem should be on-hook and in command mode. Type
AT\N0 <Enter>. This specifies a normal connection.

2. Type AT S18=10 <Enter>. This specifies a test period of 10
seconds.

3. Type AT &T1 <Enter>. This initiates the local analog loopback
test.

4. Type a simple character pattern. If your modem is working
properly, you will see this character pattern echoed to the
screen.

5. The test will end automatically after 10 seconds.

6. Return your modem to its original state by typing ATZ <Enter>.

&T2 Reserved.
&T3 Local digital loopback test. This test verifies the operation of two

connected modems and the phone channel.
For example:

1. Your modem should be on-hook and in command mode. Type
AT\N0 <Enter>. This specifies a normal connection.

2. Type AT S18=10 <Enter>. This specifies a test period of 10
seconds.

3. Establish a connection with the remote modem by typing
ATDnnn-nnnn <Enter>. Wait for the CONNECT message.

4. Issue the escape sequence to put the modem back into
command mode (type +++ without pressing <Enter>). When you
see the OK message, your modem is in command mode.

5. Issue the command AT &T3 <Enter>. This initiates the local
digital loopback test.

6. Have someone at the remote modem type a simple character
pattern. This character pattern then loops through your
modem back to the remote modem. Everything is working
properly if the original character pattern is echoed back to
the remote user’s screen.

7. The test will end automatically after 10 seconds.

8. When your testing is complete, hang up the line and return
your modem to its original state by typing ATHZ <Enter>.

&T4 Allows local modem to accept a request from the remote modem

for a remote digital loopback test. (See S23.)

&T5 Prohibits local modem from accepting a request from

the remote modem for a remote digital loopback test.

(See S23.)

&T6 Remote digital loopback test. This test verifies the operation of

two connected modems and the phone channel.
For example:

1. Your modem should be on-hook and in command mode. Type
AT\N0 <Enter>.

2. Type AT S18=10 <Enter>. This specifies a test period of 10
seconds.

3. Establish a connection with the remote modem by typing AT
Dnnn-nnnn <Enter>. Wait for the CONNECT message.

4. Issue the escape sequence to put the modem back into
command mode (type +++ without pressing <Enter>). When you
see the OK message, your modem is in command mode.

5. Issue the command AT &T6 <Enter>. This initiates the remote
digital loopback test. Note that the remote modem must support
CCITT V.54 and must be prepared to accept the request for this
test. (See &T4.)

6. Type a simple character pattern and verify that what you type
is echoed correctly to your screen.

7. The test will end automatically after 10 seconds.

8. When your testing is complete, hang up the line and return
your modem to its original state by typing ATHZ <Enter>.

&T7 Remote digital loopback with self-test. This test verifies the

operation of two connected modems and the phone channel. It
sends an internal test pattern through the loop and returns a
numeric message that indicates the number of errors that were
counted during the test period. (See &T6.)
For example:

1. Your modem should be on-hook and in command mode. Type
AT \N0 <Enter>.

2. Type AT S18=10 <Enter>. This specifies a test period of 10
seconds.

3. Establish a connection with the remote modem by typing AT
Dnnn-nnnn <Enter>. Wait for the CONNECT message.

4. Issue the escape sequence to put the modem back into
command mode (type +++ without pressing <Enter>). When you
see the OK message, your modem is in command mode.

5. Issue the command AT &T7 <Enter>. This initiates the remote
digital loopback with self-test. Note that the remote modem
must support CCITT V.54 and must be prepared to accept the
request for this test. (See &T4.)

6. The test will end automatically after 10 seconds. The number

of errors that were counted are displayed on your screen at
the end of the test. 000 means that there were no errors. 255
means that there were 255 or more errors.

7. When your testing is complete, hang up the line and return
your modem to its original state by typing ATHZ <Enter>.

&T8 Local analog loopback with self-test. This test checks the

operation of your modem’s transmitter and receiver. It sends an
internal test pattern through the loop and returns a numeric
message that indicates the number of errors that were counted
during the test period. (See &T1.)
For example:

1. Your modem should be on-hook and in command mode. Type
AT\N0 <Enter>. This specifies a normal connection.

2. Type AT S18=10 <Enter>. This specifies a test period of 10
seconds.

3. Type AT &T8 <Enter>. This initiates the local analog loopback
with self-test.

4. The test will end automatically after 10 seconds. When the test
is ended, the modem will display the number of errors
detected. 000 means that there were no errors. 255 means that
there were 255 or more errors.

5. Return your modem to its original state by typing ATZ <Enter>.

&V View Profiles Command. This command displays the active modem

profile, the user-defined profiles, and the stored telephone numbers.
(See &Wn and Zn.)

&Wn Store Current Profile Command. This command stores the active modem

configuration into nonvolatile memory (NVRAM) as user-defined
profile 0 or 1. Storable parameters can be viewed with the &V command
and recalled with the Zn command. To return to the factory defaults,
type AT& F0 <Enter>.

&W0 Store the current profile as profile 0.
&W1 Store the current profile as profile 1.

&Yn Default Reset Profile Setting. This command determines which user-

defined profile will be used after a power-on reset.

&Y0 Select user-defined stored profile 0.

&Y1 Select user-defined stored profile 1.

&Zn=X Store Telephone Number Command. This command stores a phone

number, X, to phone number entry n, where n is 0, 1, 2, or 3. Each
phone number can be up to 34 digits long. Spaces, hyphens, and
parentheses are not saved. The purpose of this command is to allow
you to abbreviate dial commands. For example, you can store the dial
string 9,[phone] by typing: AT&Z3=9,[phone] <Enter>.
Subsequent calls to this number can be issued with the command
ATDS=3 <Enter>. (See Dn, dial modifier S.

AT% Commands

%Cn Compression Control Setting. (See S41 and S46.)

%C0 Disable data compression.
%C1 Enable MNP 5 data compression only.

%C2 Enable V.42bis data compression only.

%C3 Enable both V.42bis and MNP 5 data compression.

%En Line Quality Monitor Setting. (See S41.)

%E0 Disable line quality monitoring and auto-retrain.
%E1 Enable line quality monitor and auto-retrain.

%E2 Enable line quality monitor and fallback/fall forward.

%L Line Signal Level Command. This command reports a value which

indicates the received signal level. For example, 004 = -4dBm, 043 = ­43dBm, etc.

%Q Line Signal Quality Command. This command reports the line signal

quality. Typical values are in the range from 0 to 2 and increase as the
signal quality degrades. Based on this value, retrain or fallback/fall
forward may be initiated if enabled by the %E1 or %E2 commands. The
command reports an ERROR if the modem is not connected, or is
connected at 300bps, V.23, or fax modes. In V.34, the symbol rate, SNR,
THD, TX level and pre-emphasis are also reported.

AT\ Commands

\An Maximum MNP Block Size Setting. This sets the maximum allowable

MNP block size. Block size is negotiated during the MNP handshaking.
In general, the better the line quality, the larger the blocks. (See S40.)
\A0 64 characters.

\A1 128 characters.

\A2 192 characters.
\A3 256 characters.

\Bn Break Command. In reliable mode, the modem will signal a BREAK

through the active error correction protocol. In non-error correction
mode, the modem will transmit a BREAK signal to the remote modem that
is a length n times 100 ms, where n is between 1 and 9 (the default for n
is 3). When the modem receives a break from the remote modem, the
break is passed as follows: 1) For non-corrected modes, the break length
is passed; 2) For error-corrected modes a 300mS break is passed. (See

\Kn.)

\Gn Modem-to-Modem Software Flow Control Setting. This command

enables or disables software flow control between the local and remote
modem. During a reliable connection, this setting is ignored. (See S41.)

\G0 Disable modem-to-modem software flow control.

\G1 Enable modem-to-modem software flow control.

\Kn Break Control Setting. This command allows you to send a BREAK to

stop data transfer without disconnecting. (See S40.) The resulting
behavior depends on the state of the modem:

1. Modem receives a BREAK from the computer while operating in data
mode.
\K0 Modem enters on-line command mode. No BREAK is sent to

remote modem.

\K1 Modem clears data buffers and sends BREAK to remote

modem.

\K2 Same as \K0.
\K3 Sends BREAK to remote modem immediately.
\K4 Same as \K0.

\K5 Sends break in sequence with transmitted data.

2. Modem receives a BREAK from the computer while operating in
command mode. (See \B.)

\K0 Clears data buffers and sends BREAK to remote modem.
\K1 Same as \K0.
\K2 Sends BREAK to remote modem immediately.
\K3 Same as \K2.
\K4 Sends BREAK to remote modem in sequence with data.

\K5 Same as \K4.

3. Modem receives BREAK from remote modem during non-error
corrected connection:

\K0 Clears data buffers and sends BREAK to computer.
\K1 Same as \K0.
\K2 Sends a BREAK immediately to computer.
\K3 Same as \K2.
\K4 Sends a BREAK in sequence with received data to computer.

\K5 Same as \K4

4. Modem receives BREAK from remote modem during reliable
connection: the modem passes a 300 mS BREAK to the host.

\Nn Error correction Mode Setting. This command selects the error

correction mode to be negotiated in subsequent connections. (See &Qn,

S36, and S48.)
\N0 Selects a normal connection. A normal connection is a

connection with flow control, but no error correction or data
compression. (Equivalent to &Q6.)

\N1 Same as &Q0.
\N2 Selects a reliable connection (a connection that uses error

correction). In this mode the modem will try to establish a V.42
(LAPM) or MNP connection. If the attempt fails, the modem will
hang up. (Equivalent to &Q5 S36=4 S48=7.)

\N3 Selects an auto-reliable connection. In this mode the

modem will first try to establish a reliable connection.
If it fails, it will try to establish a normal connection.

(Equivalent to &Q5 S36=7 S48=7.)

\N4 Selects LAPM error correction. If the attempt to make a LAPM

connection fails, the modem will hang up the line. -K1 may
override this command (Equivalent to &Q5 S48=0.)

\N5 Selects MNP error correction. If an attempt to make an MNP

connection fails, the modem will hang up the line. (Equivalent to
&Q5 S36=4 S48=128.)

AT) Commands

)Mn Cellular Power Level Setting. This command enables or disables the

automatic transmit power level adjustment during MNP 10 link
negotiation. The @Mn command sets the initial modem transmit level.
(See S40.)

)M0 Disable power level adjustment.

)M1 Enable power level adjustment.
)M2 Enable power level adjustment during MNP10 link

negotiation. After connection, the power level
remains fixed.

AT* Commands

*Hn Link Negotiation Speed Setting. This command controls the initial

connection speed for MNP 10 link negotiations. (See S28.)

*H0 Link negotiation at highest speed supported.

*H1 Link negotiation at 1200 bps.
*H2 Link negotiation at 4800 bps.

** Download to Flash Memory. A flash programming algorithm must first

be loaded into RAM, then the Flash PROM may be loaded. The terminal
program must be set to accept hardware and software flow control and
should be set to 8 bits, no parity, 1 stop bit. DTE speeds to 115 Kbps are
supported. Turn off character and line spacing options. You must have
both the Flash loading file and the modem hex code. WARNING: Do not
stop once the modem code is loading. The modem will be irrepairably
damaged. Before attempting this procedure, contact the factory for the
latest object code and instructions. Procedure: 1) Issue the AT**
command. Response: "Downloading initiated..." 2) Perform an ASCII file
transfer of the flash code. Response: "Downloading flash file..." 3)
Perform an ASCII file transfer of the modem hex code. Response:
"Download successful." 4) Issue the ATZ command.

AT: Commands

:En Compromise Equalizer Setting. By default, the compromise equalizer is

turned on. However, with some cellular lines, connections may be more
reliable with the compromise equalizer turned off. (See S201.)
:E0 Disable equalizer.

:E1 Enable equalizer.

AT- Commands

-Kn MNP Extended Services Setting. This command enables or disables
conversion of a V.42 LAPM connection to an MNP 10 connection. (See
S40.)

-K0 Disable conversion.

-K1 Enable conversion.

-K2 Enable conversion, except during V.42 LAPM answer

detection.

-Qn V.22bis/V.22 Fallback Setting. This command enables or disables
fallback to V.22bis or V.22. (See S41.)

-Q0 Disable fallback so that it is limited to 4800 bps.

-Q1 Enable fallback.

-SEC=X,Y MNP 10EC Cellular Protocol Settings. This command enables or

disables MNP 10EC and selects initial transmit level. Saved in
nonvolatile memory.
X=0 Disable MNP 10EC mode.
X=1 Enable MNP 10EC mode.
Y=-10 to -30 Initial transmit level in dBm. Overwritten with S91 on
factory default.

-SEC? Display MNP 10EC parameters.

-SDRnDistinctive Ring. This command permits reporting of distinctive
ringing cadences. There are three ring types: 1) 2 seconds on, 4 seconds
off; 2) 0.8 seconds on, 0.4 seconds off, 0.8 seconds on, 4.0 seconds off; 3)

0.4 seconds on, 0.2 seconds off, 0.4 seconds on, 0.2 seconds off, 0.8 seconds
on, 4.0 seconds off.
n=0 Disable distinctive ring. Any valid ring is reported as RING.
n=1 Enable Type 1 ring detection (RING1).
n=2 Enable Type 2 ring detection (RING2).
n=3 Enable Type 1 and Type 2 ring detection.
n=4 Enable Type 3 ring detection (RING3).
n=5 Enable Type 1 and Type 3 ring detection.
n=6 Enable Type 2 and Type 3 ring detection.
n=7 Enable Type 1, Type 2, and Type 3 ring detection.

AT+ Commands

+MS=X,Y,MINRATE,MAXRATE Sets protocol, automode, and speed range. Saved

in nonvolatile memory.

X=0 V.21
X=1 V.22
X=2 V.22bis
X=3 V.23
X=9 V.32
X=10 V.32bis
X=11 V.34
X=64 B103
X=69 B212
X=74 V.FC
Y=0 Fixed mode
Y=1 Automode
MINRATE and MAXRATE equals one of the following: 300, 600, 1200, 2400,

4800, 7200, 9600, 12000, 14400, 16800, 19200, 24000, 26400, 28800, 33600

2. Fax and Voice Commands

The modem supports the CCITT Group 3, and Class 1 and 2 fax command sets. We
suggest that you use your fax software to issue all the necessary fax commands
to your modem. Programmers should refer to the CCITT specification.

This modem also supports voice functions. The supplied software is designed to
work with the voice functions in this product. For further instructions on the
use of the voice features, refer to the software User Guide.

3. Result Codes and Messages

The modem responds to most AT commands with a numeric result code (0, for
example) or a verbose message (OK, for example). By default, the modem will
respond with verbose messages. A description of all of the result codes and
corresponding messages are shown in Table 3-1. The Qn, Vn, Wn, and Xn
commands and the S95 register can be used to change which result codes or
messages are displayed.