Elf Qrin's Lair


AT commands
for Hayes compatible modems


Quick Reference Table

AT - ATtention command defines speed and precedes common line
A/ - Re-executes the last command line if modem has not made a
     connection
A  - Modem goes off-hook in answer mode
B0 - Sets CCIT V.22 operation when at 1200bps
B1 - Sets Bell 212A operation when at 1200bps
C0 - Sets transmit carrier off
C1 - Sets transmit carrier on
D  - Dial number following D in command line
E0 - Modem does not echo commands back to the terminal
E1 - Modem echoes commands back to the terminal
F0 - Sets modem to half duplex
F1 - Sets modem to full duplex
H0 - Modem goes on-hook (hangs up)
H1 - Enables switchhook and auxiliary relay
I0 - Displays the product Identification Code
I1 - Performs checksum on firmware ROM and displays the value
I2 - Performs checksum on firmware ROM and returns Error or OK
L1 - Speaker volume low
L2 - Speaker volume medium
L3 - Speaker volume high
M0 - Speaker off
M1 - Speaker on until carrier detected
M2 - Speaker always on
M3 - Speaker on until carrier detected except when dialing
O0 - Return to online
O1 - Return to online with retrain
P  - Pulse (for rotary [dial] telephone service)
Q0 - Modem returns result codes
Q1 - Modem does not display result codes
Sr=n - Set S register r to value n
Sr? - Display contents of S register
T  - Tone (for touch-tone telephone service)
V0 - Short numeric result codes
V1 - Full result codes
X0 - CONNECT, result codes enabled
X1 - CONNECT BBBB result codes enabled, blind dial,
     busy signal not detected
X2 - Modem waits for dial tone before dialing, all CONNECT BBB
     result codes enabled, busy signal not detected
X3 - Modem blind dials, all CONNECT BBBB results codes enabled,
     modem sends BUSY if busy signal is detected
X4 - Modem waits for dial tone before dialing, all CONNECT BBBB
     results codes enabled, modem sends BUSY if busy signal is
     detected
Y0  - Long space disconnect disabled
Y1  - Long space disconnect enabled
Z   - Load stored profile configuration
&C0 - DCD always ON
&C1 - DCD ON if data carrier is present
&D0 - Modem ignores DTR
&D1 - Modem assumes command state with an ON-to-OFF transition on
      DTR
&D2 - Modem hangs up, assumes command state and disables auto
      answer once detecting ON-to-OFF transition on DTR
&D3 - Modem assumes initialization state with an ON-to-OFF
      transition to DTR
&F  - Load factory profile configuration
&G0 - No guard tone
&G1 - 550 Hz guard tone
&G2 - 1800 Hz guard tone
&L0 - Selects dialup line
&L1 - Selects leased line
&P0 - Pulse dial make/break ratio 39/61 (USA/Canada)
&P1 - Pulse dial make/break ratio 33/67 (UK/HK)
&R0 - CTS follows RTS
&R1 - Modem ignores RTS; CTS is always on
&S0 - DSR is always ON
&S1 - DSR is compatible with EIA RS-232C
&T0 - Ends a test in progress
&T1 - Initiate Local Analog Loopback Test
&T2 - RESERVED
&T3 - Initiate Digital Loopback
&T4 - Grants request from remote modem for Digital Loopback
&T5 - Denies request from remote modem for Digital Loopback
&T6 - Initiate Remote Digital Loopback Test
&T7 - Initiate Remote Digital Loopback Test with Self Test
&T8 - Initiate Local Analog Loopback Test with Self Test
&W -  Write present profile configuration to nonvolatile RAM
&Z  - Stores a phone number in nonvolatile RAM

S - Registers:

S0  - Ring to answer         0-255 rings      default:0
S1  - Number of rings        0-255 rings      default:0
S2  - Escape character       0-127 ASCII      default:43(+)
S3  - Carriage Return        0-127 ASCII      default:13(CR)
S4  - Line Feed              0-127 ASCII      default:10(LF)
S5  - Back Space             0-127 ASCII      default:8(BS)
S6  - Wait for dial tone     2-255 seconds    default:2
S7  - Wait for carrier       1-255 seconds    default:30
S8  - Comma pause time       0-255 seconds    default:2
S9  - Carrier response       1-255 .1 sec.    default:6
S10 - Carrier loss delay     1-255 .1 sec.    default:7
S11 - Tone duration          50-255 msec.     default:70
S12 - Escape guard time      20-255 .02 sec   default:50
S13 - Bit mapped UART status register
S14 - Bit mapped Option register
S15 - Bit mapped Flag register
S16 - Bit mapped Test options
S17 - RESERVED
S18 - Test times            1-255 seconds        default:0
S19 - RESERVED
S20 - RESERVED
S21 - Bit mapped
S22 - Bit mapped
S23 - Bit mapped
S24 - RESERVED
S25 - Delay to DTR          0-255 .01 sec.       default:5
S26 - RTS to CTS delay      0-255 .01 sec.       default:1

AT command syntax

All “AT” commands are preceded with the ASCII characters AT (Attention Code) and terminated with a Carriage Return. Prior to terminating the command line, you can edit mistakes by using the Backspace key. This will delete the last character entered, but it will not delete the AT at the beginning of the line. Typing AT on its own will result in the OK message being returned by the modem

The AT characters can be issued using either upper or lower case characters, but not a combination of the two. You are allowed to enter more than one command on a line between the AT and the Carriage Return. Spaces are ignored.

AT commands

ATA Answer

This command causes the modem to pick up the line and go to line in answer mode immediately. An incoming ring signal does not have to be detected by the modem. The modem will issue answer frequencies and attempt to train up to calling modem. If a connection is not established within the time period defined by S register 7, then the NO CARRIER message will be displayed.

A Answer immediately - force modem off-hook and into answer mode.

ATB Mode of operation

This command is used to put the modem into BELL mode or ITU-T (CCITT) mode. Bell modes are American modes of operation at 300bps or 1200bps.

B0 Set to standard ITU-T (CCITT) protocols
B1 Set Bell modes.

ATD Dial command and dial modifiers

ATD causes the modem to dial according to the suffixed modifier. eg. ATDT12345 causes the modem to Tone dial 12345.

Dnnn Dial Telephone number (nnn).

Dial string modifiers:

^ Changes the state of call tone
P Set to pulse dialling
T Set to tone (DTMF) dialling
, Pause (S8) seconds before next digit
W Wait for dial tone
@ Wait for quiet answer
& Wait for credit card (bong) tone before continuing with the dial string
; Return to command mode after dialling
S=n Dial number stored in location n
*#ABCD Additional DTMF tone codes
L Dial last number called

ATE Command echo

The ATE command controls the echoing of commands to the DTE device when in command mode.

E0 Command characters not echoed to the DTE
E1 Command characters echoed to the DTE

ATH Hang up

The ATH command puts the modem into an on-hook or off-hook state eg. when in command mode ATH would disconnect the call by hanging up the line.

H0 Set the modem on-hook
H1 Set the modem off-hook

ATI Interrogate modem

The ATI commands interrogate the modem and returns the relevant information.

I0 Request product code
I1 Request firmware checksum
I2 Validate internal firmware checksum (OK response)
I3 Request software release code
I4 Product identifier.

ATL Speaker volume

The ATL commands are used to set speaker volume where appropriate.

L0 Set lowest speaker volume
L1 Set low speaker volume
L2 Set medium speaker volume
L3 Set high speaker volume

ATM Speaker control

The ATM command controls when a speaker is active.

M0 Turn loudspeaker off at all times
M1 Enable loudspeaker until carrier is detected
M2 Enable loudspeaker whenever modem is off-hook
M3 Enable loudspeaker after dialling and until carrier is detected

ATN Automode detection

The ATN command controls the automode detection.

N0 Automode detection is disabled (equivalent to setting the +MS<automode> subparameter to 0) A subsequent handshake will be conducted according to the value of S37 or, if S37 is set to 0, according to the most recent DTE speed.
N1 Automode detection is enabled. A subsequent handshake will be conducted according to the contents of S37 or, if S37 is 0, starting at V.34 33,600bps.

ATO Modem on-line

The ATO command is to return a modem to data mode when it is on line and in command mode.

O0 Return modem to Data mode
O1 Return modem to Data mode and initiate retrain sequence

ATQ Quiet message control

This command is used to switch result codes from the modem to the DTE device on or off.

Q0 Enable response codes to the DTE
Q1 Disable response codes to the DTE

ATS Set S register

The ATS command is used to either read the value of an S register or set it to another value. See the Special Commands and Features section for more details.

Sr? Return the contents of Register r to the DTE
Sr=n Set the contents of Register r to n

ATV Result code format

The ATV command determines the format of the result messages returned by the modem.

V0 Send numeric result code set
V1 Send verbose code set

ATW Connect message format

This command determines the format of the messages returned by the modem when it connects in error corrected mode.

W0 Report DTE speed only e.g. CONNECT 57600
W1 Report line speed, EC protocol and DTE speed
W2 Report DCE speed only e.g. CONNECT 33600

ATX Result code set and blind dialling

The ATX command determines which result code set is to be used by the modem and also determines the level of network tone recognition. See the Messages from the Modem section on page XXX for a full listing of the result codes that the modem can generate when in basic or extended mode.

X0 Select basic result code and disable all network tone recognition
X1 Select extended result codes and disable all network tone recognition
X2 Select extended result codes and enable dial tone recognition
X3 Select extended result codes and enable busy tone recognition
X4 Select extended result codes and enable both busy and dial tone recognition

ATY Break disconnect format

This command is used to switch the break disconnect off or on. When the modem is in a non error corrected mode and the long space disconnect is switched on, the modem will transmit a 4 second break before going on hook. In error corrected mode the modem will go on hook if it receives a break of greater than 1.6 seconds.

Y0 Disable long space disconnect
Y1 Enable long space disconnect

ATZ Modem reset

The ATZ command resets the modem to the profile selected. For example, ATZ1 will reset the modem to profile 1. If no profile number is specified, profile 0 will be used.

Zn Reset the modem and load configuration n, where n is 0 or 1.

AT&C Data carrier detect

AT&C controls how the modem presents the DCD signal.

&C0 DCD is always on
&C1 DCD follows carrier

AT&D DTR options

The AT&D command in conjuntion with the AT&Q command determines how the modem will react to a loss of DTR.

&D0 Interpret DTR transition as per &Qn
&Q0, &Q5, &Q6 The modem ignores DTR
&Q1, &Q4 The modem hangs up
&Q2, &Q3 The modem hangs up, auto-answer is inhibited
&D1 Interpret DTR transition as per &Qn
&Q0, &Q1, &Q4, &Q5, &Q6 Asynchronous escape to command state
&Q2, &Q3 The modem hangs up, auto-answer is inhibited
&D2 Interpret DTR transition as per &Qn

The modem hangs up, auto-answer is inhibited

&D3 Interpret DTR transition as per &Qn
&Q0, &Q1, &Q4, &Q5, &Q6 The modem performs soft reset
&Q2, &Q3 The modem hangs up, auto-answer is inhibited

AT&F Restore factory configuration

This command loads the factory default configuration

&F0 Load factory configuration 0
&F1 Load factory configuration 1

AT&K Flow control options

The AT&K command selects the type of flow control to be used by the modem. Flow control is essential when the DTE speed is greater than the actual line speed.

&K0 Disable flow control
&K3 Enable RTS/CTS flow control
&K4 Enable XON/XOFF flow control
&K5 Support transparent XON/XOFF flow control
&K6 Enable RTS/CTS and XON/XOFF flow control

AT&Q Asynchronous/Synchronous operation

The AT&Q command selects the data and transmission mode.

&Q0 Select direct asynchronous mode
&Q4 Selects Autosync operation. Provides synchronous communications capability from an asynchronous terminal when used in conjunction with appropriate software.
&Q5 Modem negotiates an error corrected link
&Q6 Select asynchronous operation in normal mode

AT&R CTS control

AT&R controls the response of the CTS signal. CTS is also affected by the AT&K command.

&R0 CTS operates in accordance with V.25bis handshake
&R1 CTS controlled by flow control

AT&S DSR control

This command determines how the DSR signal operates.

&S0 DSR always ON.
&S1 DSR operates in accordance with V.24 spec.

AT&T Loopback test options

These commands are used to perform V.54 modem self tests. The tests operate for the length of time specified in S register 18. If this is set to 0, tests can be cancelled by AT&T0.

&T0 Terminate any test in progress.
&T1 Initiate Local Analogue Loop-back Test.
&T3 Initiate Local Digital Loop-back Test.
&T4 Accept requests for remote Digital Loop-back.
&T5 Deny requests for remote Digital Loop-back.
&T6 Initiate remote Digital Loop-back Test (V.54) without self test.
&T7 Initiate remote Digital Loop-back Test with self test.
&T8 Initiate local analogue loop back with self test

AT&V Display modem configuration

AT&V displays the current configurations and the other stored profiles.

&V Display current configuration.

AT&W Save to non-volatile memory

This command saves the current configuraion into non-volatile memory.

&Wn Write active configuration to stored profile n where n is 0 or 1.

AT&Y Set power on default

AT&Y determines which profile is to be loaded when the modem is powered on e.g.
AT&Y1
means that the profile stored in location 1 is loaded on power up.
&Yn Load configuration profile n at power-up, where n is 0 or 1.

AT&Z Store telephone numbers

The AT&Z command stores a telephone number into the modems telephone directory. There are 15 telephone locations available, each containing up to 24 digits. eg. AT&Z2=12345 stores the telephone number 12345 in location 2.

&Z=n Store first telephone number.
&Z1=n Store second telephone number.
&Z14=n Store fifteenth telephone number.

AT\A Set MNP packet sizes

The AT\A command sets the maximum block size used during an MNP connection. This command is only used when the phone line is very noisy.

\A0 Set max. packet size to 60
\A1 Set max. packet size to 128
\A2 Set max. packet size to 192
\A3 Set max. packet size to 256

AT\B Set Transmit break

The AT\B command is used to transmit a break from the local modem to the remote modem.

\Bn Send break of n (n = 1-9) durations of 100ms.

AT\F Display telephone directory

AT\F displays the telephone numbers stored in the modem's directory.

\F Display telephone directory.

AT\K Break control

The AT\K command determines how the modem will react when a break is received. A break can be received by the modem from the remote modem, or the DTE device, or from the local modem with the AT\B command. This command only affects the modem in non-error corrected links.

\K0 Break from DTE causes the modem to enter command mode and not transmit break.

Break command causes the modem to purge its' buffers and transmit break to line
Break from remote modem causes the modem to purge its' buffers and transmit break to DTE

\K1 Break from DTE causes the modem to purge its' buffers and transmit break to line.

Break command causes the modem to purge its' buffers and transmit break to line.
Break from line causes the modem to purge its' buffers and transmit break to DTE.

\K2 Break from DTE causes modem to enter command mode and not transmit break.

Break command causes modem to transmit break to line immediately.
Break from line causes modem to transmit break to DTE immediately.

\K3 Break from DTE causes modem to transmit break to line immediately.

Break command causes the modem to transmit break to line immediately.
Break from line causes modem to transmit break to the DTE immediately.

\K4 Break from DTE causes modem to enter command mode and not transmit break.

Break command causes modem to transmit break to line in sequence with the data
Break from line causes modem to transmit break to the DTE in sequence with the data.

\K5 Break from DTE causes modem to transmit break to line in sequence with the data.

Break command causes modem to transmit break to line in sequence with the data.
Break from line causes modem transmit break to DTE in sequence with the data.

AT\N Error correction protocol

AT\N selects the error correction protocol to be used by the modem. Both LAPM and MNP4 are supported. eg. AT\N4 will cause the modem to establish a LAPM error corrected link only, if an error corrected link cannot be established the call is dropped. In reliable or auto-reliable V.42 mode, LAPM takes precedence over MNP.

\N0 Disable MNP and LAPM operation
\N1 Disable MNP and LAPM operation.
\N2 Enable reliable V.42 operation.
\N3 Enable auto-reliable V.42 operation (fallback to normal).
\N4 Enable reliable LAPM.
\N5 Enable reliable MNP operation .

AT+MS Select line modulation

This extended format command selects the modulation, enables or disables automode, and specifies the lowest and highest connection rates using one to four subparameters. The command format is AT+MS= <mode>,<automode>,<min-rate>,<max-rate>

Example : to force the modem to use V.34 line modulation, autodetect line speed, and accept a minimum connection of 300bps and a maximum connection of 33600bps, use the command :

AT+MS= 11,1,300,33600 this is the default setting.

Example : to force the modem to use V.32bis line modulation with the data rate fixed to 4800bps, use the command :

AT+MS= 10,0,4800,4800

To determine what options are currently selected, use the command:

AT+MS?

This command returns the current selected parameters e.g. 11,1,300,33600.

To determine what options the modem supports, use the command:

AT+MS=?

This command returns the available parameter values:

(0,1,2,3,9,10,11,64,69,74),(0,1),(300-33600),(300-33600)

The parameters for the AT+MS command are as follows :-

<mode> Modulation <min-rate> <max - rate>

0 V.21 300
1 V.22 1200
2 V.22bis 2400
3 V.23 1200
9 V.32 9600, 4800
10 V.32bis 14400, 12000, 9600, 7200, 4800
11 V.34 33600, 31200, 28800, 26400, 24000, 21600, 19200, 16800, 14400, 12000, 9600, 7200, 4800, 2400
64 Bell 103 300
69 Bell 212 1200
74 V.FC 28800, 26400, 24000, 21600, 19200, 16800, 14400

<automode>Option

0 Automode disabled
1 Automode enabled (default)

AT%C Data compression options

The AT%C command is used to select the data compression mode. The modem supports both MNP5 and V.42bis.

%C0 Disable MNP5 and V.42bis data compression.
%C1 Enable MNP class 5 data compression only.
%C2 Enable V.42bis and disable MNP5
%C3 Enable V.42bis and MNP5

AT%E Auto retrain options

This command selects the auto-retrain facility. When enabled, the modem monitors the line quality and performs a retrain when the line deteriorates. If retraining is unsuccessful, the modem disconnects the call.

%E0 Disable line quality monitor and auto retrain
%E1 Enable line quality monitor and auto retrain
%E2 Enable line quality monitor and fallback/fall forward

AT%L Receive line signal level

The AT%L command reports the receive line signal level. This command is used when the modem is on line but in command mode. A value of 009 indicates a receive line of -9dBm.

%L Return received line signal level

AT%Q Receive line noise level

The AT%Q command reports signal quality. This command is used when the modem is on line but in command mode. The higher the returned value, the noisier the line.

%Q Report line signal quality

AT-K MNP10 options

This command enables or disables conversion of a V.42 LAPM connection to an MNP10 connection.

-K0 Disable MNP10 extended services
-K1 Enable MNP10 extended services

Factory defaults

The factory default modem configuration corresponds to the following commands:

B0 E1 F0 L3 M1 N1 Q0 T V1 W1 X4 Y0
&C1 &D2 &K3 &Q5 &R1 &S0
\A1 \B3 \K5 \N3 %C3 %E2

Special commands and features

A/ and +++ commands

There are two modem configuration commands that must not be preceded by the AT attention code:

1) A/

Typing A/ in the terminal emulation window causes the modem to re-execute the command previously entered. Note that it is not necessary to follow A/ with a carriage return.

2) +++

When in Data mode, if the string +++ is sent to the modem preceded and followed by a pause (which by default is one second), the modem will exit from Data mode and enter command mode. Meanwhile, the call is not automatically disconnected; data mode can be resumed by issuing the ATO command, or the call manually disconnected by issuing ATH command.

Hayes autosync mode

Your modem implements the Hayes Autosync protocol. This allows the modem to connect to synchronous devices such as AS400's and mainframe computers. The Autosync feature is enabled by optional software you may have purchased .

Fax mode

Your modem is capable of sending and receiving faxes. Fax operation is controlled automatically by the software which may have been supplied with your modem.

Your modem can send and receive faxes at up to 14400bps. The fax feature is compatible with Group 3 fax machines and fully compliant with the Class 1 and Class 2 control standards.

Messages from the modem

Your modem responds to commands and events by sending Result Codes. Result codes can be verbal (the default setting) or numeric, or can be turned off entirely. You can easily understand the verbal form, but your computer may find it easier to handle the numeric form. The table below lists the Hayes digital codes and their verbal equivalents.

Numeric Long form

00 OK
01 CONNECT
02 RING
03 NO CARRIER
04 ERROR
05 CONNECT 1200
06 NO DIALTONE
07 BUSY
08 NO ANSWER
09 CONNECT 0600
10 CONNECT 2400
11 CONNECT 4800
12 CONNECT 9600
13 CONNECT 7200
14 CONNECT 12000
15 CONNECT 14400
16 CONNECT 19200
17 CONNECT 38400
18 CONNECT 57600
19 CONNECT 115200
22 CONNECT 75TX/1200RX
23 CONNECT 1200TX/75RX
24 DELAYED
32 BLACKLISTED
33 FAX
35 DATA
40 CARRIER 300
44 CARRIER 1200/75
45 CARRIER 75/1200
46 CARRIER 1200
47 CARRIER 2400
48 CARRIER 4800
49 CARRIER 7200
50 CARRIER 9600
51 CARRIER 12000
52 CARRIER 14400
53 CARRIER 16800
54 CARRIER 19200
55 CARRIER 21600
56 CARRIER 24000
57 CARRIER 26400
58 CARRIER 28800
59 CONNECT 16800
61 CONNECT 21600
62 CONNECT 24000
63 CONNECT 26400
64 CONNECT 28800
66 COMPRESSION : CLASS5
67 COMPRESSION :V42BIS
69 COMPRESSION : NONE
70 PROTOCOL : NONE
77 PROTOCOL : LAPM
78 CARRIER 31200
79 CARRIER 33600
80 PROTOCOL : ALT
81 PROTOCOL : ALT-CELLULAR
83 CONNECT 31200
84 CONNECT 33600

The result codes shown comprise the Extended Command set. Result codes 0-4, 6-8 and 16-18 comprise the Basic Command set.

You can disable or enable result codes using the ATQ command. Numeric or verbal result codes are selected using the ATV command. The ATX command is used to determine whether the Extended or Basic result code set is used.

S Registers

Your Gold Card Global Modem has a set of internal registers, known as “S” registers, which are used to control the fine details of its operation. Most of the “S” registers are not applicable to every day usage of your Gold Card Global Modem and can be ignored.

Notes:

1) The number in brackets following the S register number is the default factory setting.
2) When specifying bit-mapped registers with multiple options, the bit pattern is displayed in binary format starting with the most significant bit to the left.
3) Modifying the contents of bit-mapped S registers is not recommended.
4) All S Register values must be input as 8-bit decimal numbers.

S0 (0) Auto Answer Ring Number.

Units: Rings Range: 0 - 255
Defines the number of ring bursts before the modem automatically answers an incoming call. When set to zero, auto-answer is disabled.

S1 (0) Incoming Ring Count (read only register).

Units: Rings Range: 0 - 255
Counts the number of ring bursts received. Reset to zero after 8 seconds of no ring.

S2 (43) Escape Character.

Units: ASCII Range: 0 - 127
Defines the ASCII character used to exit into command mode from data mode. A value greater than 127 disables escape code detection.

S3 (13) Carriage Return Character.

Units: ASCII Range: 0 - 127
Specifies the ASCII code to be used as carriage return.

S4 (10) Line Feed Character.

Units: ASCII Range: 0 - 127
Specifies the ASCII code to be used as line feed.

S5 (8) Backspace Character.

Units: ASCII Range: 0 - 127
Specifies the ASCII character to be used to erase the last command character entered.

S6 (4) Wait time for dial tone before blind dialling.

Units: Seconds Range: 4-7
Determines the period of time that the modem waits after connecting to line before commencing blind-dialling of the telephone number specified. The W modifier in the dial string will override this and cause the modem to wait for a dial tone before commencing dialling.

S7 (40) Wait for carrier or Silence after dialling.

Units: Seconds Range: 1 - 58
Determines the period of time that the modem waits for carrier from the remote modem before hanging up.

S8 (4) Pause time for the comma (,) dial modifier.

Units : seconds - Range : 4- 11
This register contains the pause time of the (,) dial modifier used in the dial string. Consecutive commas will invalidate the modem's approval if the total pause period exceeds 12 seconds.

S9 (6) Carrier detect response time.

Units : tenths of a second - Range : 1-255
This register contains the time period that a received carrier signal must be present for the modem to recognise it and turn on the DCD signal.

S10 (14) Loss of carrier to hang up delay time.

Units : tenths of a second - Range : 1 - 255
This register contains the time period that the modem takes to disconnect from the telephone line upon detection of loss of carrier. If S10 is set to a value less than S9 any loss of carrier will result in disconnection. The loss of carrier time period that can be tolerated is the difference between S9 and S10.

S11 (95) Duration and spacing of DTMF tones.

Units: milliseconds - range:50-255
This register contains the time period of the duration and inter-digital pause of the DTMF dialling tones. This is a read only register.

S12 (50) Escape code guard time.

Units : fiftieths of a second - range: 0-255
This register contains the time period of the escape code guard time. The escape code guard time is the delay required prior to and immediately succeeding the escape code. If the guard time is defined as 0, there will be no guard time and 3 consecutive escape characters will cause the modem to enter the command mode.

S14 (138) Bit mapped register.

Bit 0 Reserved
Bit 1 0 Disable command echo.
1 Enable command echo.
Bit 2 0 Enable result codes.
1 Disable result codes.
Bit 3 0 Short form result codes.
1 Long form result codes.
Bit 4 Reserved
Bit 5 0 DTMF dial.
1 Pulse dial.
Bit 6 Reserved.
Bit 7 0 Answer
1 Originate

S16 (0) Test options, bit mapped (read only register).

Bit 0 0 Local analogue loop-back inactive.

1 Local analogue loop-back active.

Bit 1 Reserved

Bit 2 0 Local digital loop-back inactive.

1 Local digital loop-back active.

Bit 3 0 Remote digital loop-back requested from remote modem active.

1 Remote digital loop-back requested from remote modem active.

Bit 4 0 Status bit, remote digital loop-back inactive.

1 Status bit, remote digital loop-back active.

Bit 5 0 Remote digital loop back disabled

1 Remote digital loop back enabled

Bit 6 0 Local analogue loop back disabled

1 Local analogue loopback enabled

Bit 7 Not used.

S18 (0) Test timer.

Units : seconds - Range 0-255

This register defines the time period (in seconds) of the modems diagnostic tests. When a test has been active for a period given by the register then the modem will automatically cancel the test. A value of 0 will disable the test timer and any test will remain active until cancelled by the user.

S21 (52) Bit mapped register.

Bit 0 0 &J0

1 &J1

Bit 1 Reserved

Bit 2 0 CTS always on.

1 CTS tracks RTS.

Bits 4,3 00 DTR is ignored.

01 Enter command state when DTR inactive.

10 Clear down call when DTR inactive.

11 Clear down call and reset when DTR inactive.

Bit 5 0 DCD always active.

1 DCD is active when carrier present.

Bit 6 0 DSR always active.

1 DSR active in data mode only.

Bit 7 0 Long space disconnect disabled.

1 Long space disconnect enabled.

S22 (119) Bit mapped register.

Bits 1,0 00 Speaker off

01 Speaker low

10 Speaker medium

11 Speaker high

Bits 3,2 00 Speaker disabled.

01 Speaker on until carrier.

10 Speaker always on.

11 Speaker on until carrier, off when dialling.

Bit 6,5,4 000 Basic result codes, no busy, blind dials.

100 Extended result codes, no busy, blind dials.
101 Extended result codes, no busy, detects dialtone.
110 Extended result codes, detects busy, blind dials.
111Extended result codes, detects busy and dialtone.

Bit 7 Reserved

S23 (182) Bit mapped register.

Bit 0 0 disable remote request for remote digital loop-back.

1 enable remote request for remote digital loop-back.

Bit 3,2,1 000 DTE baud rate = 300

010 DTE baud rate = 1200
011 DTE baud rate = 2400
100 DTE baud rate = 4800
101 DTE baud rate = 9600
111 DTE baud rate = 19200

Bit 5,4 00 parity even

01 not used
10 odd parity
11 no parity

Bit 7,6 Reserved

S25 (5) Delay to DTR

Units : seconds - Range 0-255

Sets the length of time that the modem will ignore DTR before hanging up.

S26 (1) RTS to CTS delay

Units : hundredths of a second - Range : 0-255

Sets the time delay before the modem turns CTS on after detecting an off-to-on transition on RTS when &R0 is commanded.

S27 (9) Bit mapped

Bit 0,1,3 0,0 &M0 or &Q0

1,0 &M1 or &Q1
2,0 &M2 or &Q2
3,0 &M3 or &Q3
0,1 &Q4
1,1 &Q5
2,1 &Q6

Bit2,4,5 Reserved

Bit 6 0 CCITT mode

1 Bell mode

Bit 7 Reserved

S29 (0) Flash dial modifier

Units : 10 milli seconds - Range : 0-255

Sets the length in time, in units of 10ms, that the modem will go on-hook when it encounters the flash (!) dial modifier in the dialstring.

S30 (0) Disconnect inactivity timer.

Units : tens of seconds - Range : 0-255

Sets the length of time that the modem will stay on line before disconnecting when no data is sent or received. In error correction mode, any data transmitted or received will reset the timer. In other modes, any data transmitted will reset the timer.

S31 (194) Modem modes.

Bit 0 Reserved

Bit1 0 line speed detection disabled

1 line speed detection enabled

Bit 2,3 00 Error correction progress messages report DTE speed only

01Full report given

10 DCE speed only reported

Bit 4,5,6,7 Reserved

S32 (17) XON character.

Units : ASCII - Range 0-255

Sets the value of the XON character.

S33 (19) XOFF character

Units : ASCII - Range : 0-255

Sets the value of the XOFF character.

S36 (7) LAPM failure control.

This value indicates what should happen upon a LAPM failure. These fallback options are initiated upon connection if S48=128.

Bit 0,1,2 000 Modem disconnects

001 Modem stays on line and a direct mode connection is established
010 Reserved
011 Modem stays on line and a normal mode connection is established
100 An MNP connection is attempted and if it fails the modem disconnects
101 An MNP connection is attempted and if it fails a direct mode connection is established
110 Reserved
111 An MNP connection is attempted and if it fails a normal mode connection is established

Bit 3,4,5,6,7 Reserved

S37(0) Desired line connection speed

Bit 4, 3,2,1,0 00000 Attempt auto mode connection

00010 Attempt to connect at 300bps
00100 Attempt to connect at 300bps
00110 Attempt to connect at 300bps
00100 Reserved
00101Attempt V32bis/V32 4800bps
0110 Attempt to connect at 2400bps
11000 Attempt to connect at V23
11100 Attempt V32bis/V32 9600bps
11110 Attempt V32bis 12000bps

S38 (20) Delay before hanging up.

Units : seconds - Range 0-255

This register determines the time period that the modem waits before dropping the line when in error correction mode.

S39 (3) Flow control

Bits 2,1,0 000 No flow control

011 RTS/CTS

100 XON/XOFF
101 Transparent XON
110 Both methods

Bits 7,6,5,4,3 Reserved

S40 (104) Bit mapped

Bit 0 0 Disable extended MNP services

1 Enable extended MNP services

Bit 1 Reserved

Bit 2 0 MNP link negotiation at highest speed

1 MNP link negotiation at 1200bps

Bit 5,4,3 000 \K0

001 \K1
010 \K2
011 \K3
100 \K4
101 \K5

Bit 7,6 00 MNP block size 64 characters

01 128 characters
10 192 characters
11 256 characters

S41 (195) Bit mapped

Bit 1,0 00 Compression disabled

01 MNP5

10 V42bis

11 MNP5 and V42bis

Bit 2 0 Retrain disabled

1 Retrain enabled

Bit 3 0 Modem to modem flow control disabled

1 Enabled

Bit 4 0 Stream mode

1 Block mode

Bit 7,6,5 Reserved

S46 (138) Data compression control.

Range : 136 or 138

136 Execute error correction protocol with no compression

138 Execute error correction protocol with compression

S48 (0) V.42 negotiation action

Range : 0, 7 or 128

The V.42 negotiation process determines the capabilities of the remote modem. However, when the capabilities of the remote modem are known and the negotiation is unnecessary, this process can be bypassed if so desired.

If an invalid number is entered, it is accepted but S48 will act as if 128 has been entered.

7 Enable negotiation

0 Disable negotiation

128 Disable negotiation; bypass detection and proceed with LAPM

S86 (0) Connection failure identification (read only register).

This register gives diagnostic information regarding why the modem failed to connect.

0 Normal disconnection, no error occurred

4 Loss of carrier

5 V.42 failed to detect an error corrected modem at the other end

9 The modems could not find a common protocol

12 Normal disconnect initiated by the remote modem

13 Remote modem does not respond after 10 re-transmissions

14 protocol violation

S95 (44) Extended result codes

Bit 0 Connect result code indicates DCE speed instead of DTE speed

Bit 1 Append /ARQ to connect XXX result code if error correction is on

Bit 2 Enable carrier XXX result code

Bit3 Enable protocol XXX result code

Bit 4 Reserved

Bit 5 Enable compression result code

Bit 6,7 Reserved



Issued on Elf Qrin's Hacking Lab
Legal notices and disclaimer