Basic AT Commands

Command Function

A/      Re-execute command.
A       Go off-hook and attempt to answer a call.
B0      Select V. 22 connection at 1200 bps.
B1      Select Bell 212A connection at 1200 bps.
C1      Return OK message.
Dn      Dial modifier.
E0      Turn off command echo.
E1      Tun on command echo.
H0      Initiate a hang-up sequence.
HI      If on-hook, go off-hook and enter command mode.
I0      Report product code.
I1      Report computed checksum..
I2      Report OK.
I3      Report firmware revision, model, date
I4      Report response programmed by an OEM
I5      Report the country code parameter.
I6      Report modem data pump model and code revision. .
L0      Set low speaker volume
LI      Set low speaker volume
L2      Set medium speaker volume
L3      Set high speaker volume.
M0      Turn speaker off.
M1      Turn speaker on during handshaking and turn speaker off while
        receiving carrier. 
M2      Turn speaker on during handshaking and while receiving carrier
M3      Turn speaker off during dialing and receiving carrier and turn
        speaker during answering. 
N0      Turn off Automode detection. 
N1      Turn on Automode detection.
O0      Go on-line.
O1      Go on-line and initiate a retrain sequence.
P       Force pulse dialing.
Q0      Allow result codes to DTE.
Q1      Inhibit result codes to DTE.

Sn      Select S-Register as default.
Sn?     Return the value of S-Register n.
Sn=v    Set default S-Register to value v.
S=?     Return the value of default S-Register.
T       Force DTMF dialing.
V0      Report short from (terse) result codes.
V1      Report long from (verbose) result codes.
W0      Report DTE speed in Error Correction mode.
W1      Report line speed. Error Correction protocol and DTE speed.
W2      Report DCE speed in Error Correction mode.
X0      Report basic call progress result codes, i.e., OK, CONNECT.
        RING, NO CARRIER (also. for busy, if enabled, and dial tone
        not detected), NO ANSWER and ERROR.
XI      Report basic call progress result codes and connections speeds
        (OK, CONNECT, RING. NO CARRIER (also, for busy, if enabled, and dial
        tone not detected), NO ANSWER, CONNECT, XXXX, and ERROR.
X2      Report basic call progress result codes and connections
        speeds, i.e.. OK,CONNECT. RING, NO CARRIER (also, for busy,
        if enabled, and dial tone not detected), NO ANSWER, CONNECT.
        XXXX, and ERROR.
X3      Report basic call progress result codes and connection rate,
        i. e., OK, CONNECT RING, NO CARRIER, NO ANSWER, CONNECT XXXX,
        BUSY, and ERROR
X4      Report all call progress result codes and connection rate. i. e.,
        OK.CONNECT, RING, NO CARRIER, NO ANSWER,CONNECT XXXX, BUSY,
        NO DIAL TONE and ERROR.
Y0      Disable long space disconnect before on-hook.
Yl      Enable long space disconnect before on-hook.
Z0      Restore stored profile 0 after warm reset.
Z1      Restore stored profile 1 after warm reset.


&C0     Force RLSD (DCD) active regardless of the carrier state.
&C1     Allow RLSD (DCD) to follow the carrier state.
&D0     Interpret DTR ON-to-OFF transition per &Qn.
&D1     Interpret DTR ON-to-OFF transition per &Qn.
&D2     Interpret DTR ON-to-OFF transition per &Qn.
&D3     Interpret DTR ON-to-OFF transition per &Qn.
&FO     Restore factory configuration 0.
&F1     Restore factory configuration 1.
&G0     Disable guard tone.
&G1     Disable guard tone.
&G2     Enable 1800 Hz guard tone.
&K0     Disable DTE/DCE flow control.
&K3     Enable RTS/CTS DTE/DCE flow control.
&K4     Enable XON/XOFF DTE/DCE flow control.
&K5     Enable transparent XON/XOFF flow control.
&K6     Enable both RTS/CTS and XON/XOFF flow control.
&M0     Select direct asynchronous mode.
&M1     Select sync connect with async off-line command mode.*
&M2     Select sync connect with async off-line command mode and
        Enable DTR dialing of directory zero.*
&M3     Select sync connect with async off-line command mode and
        Enable DTR to act as Talk/Data switch.*
&P0     Set 10 pps pulse dial with 39%61% make/break, (country dependent)
&P1     Set 10 pps pulse dial with 33%67% make/break, (country dependent)
&P2     Set 20 pps pulse dial with 39%61% make/break, (country dependent)
&P3     Set 20 pps pulse dial with 33%67% make/break, (country dependent)
&Q0     Select direct asynchronous mode.
&Q1     Select sync connect with async off-line command mode.*
&Q2     Select sync connect with async off-line command mode and
        Enable DTR dialing of directory zero.*
&Q3     Select sync connect with async off-line command mode and
        Enable DTR to act as Talk/Data switch.*
&Q4     Select Hayes  AutoSync mode.
&Q5     Modem negotiates an error corrected link.
&Q6     Select asynchronous operation in normal mode.
&R0     CTS tracks RTS (async) or acts per V. 25 (sync).
&R1     CTS is always active.
&S0     DSR is always active.
&S1     DSR acts per V. 25.
&T0     Terminate any test in progress.
&T1     Initiate local analog loopback.
&T2     Returns ERROR result code.
&T3     Initiate local digital loopback.
&T4     Allow remote digital loopback.
&T5     Disallow remote digital loopback request.
&T6     Request an RDL without self-test.
&T7     Request an RDL with self-test.
&T8     Initiate local analog loop with self-test.
&V      Display current configurations.
&V1     Display the last connection statistics.
&W0     Store the active profile in NVRAM profile 0.
&W1     Store the active profile in NVRAM profile 1.
&X0     Select internal timing for the transmit clock.*
&X1     Select external timing for the transmit clock.*
&X2     Select slave receive timing for the transmit clock.*
&Y0     Recall stored profile 0 upon power up.
&Y1     Recall stored profile 1 upon power up.
&Zn=x   Store dial string x (to 45) to location n (0 to 3).
%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.
%E3     Enable line quality monitor and auto-retrain with Fast hang-up.
%L      Return received line signal level.
%Q      Report the line signal quality.
\Kn     Controls break handing three states.
\N0     Select normal speed buffered mode.
\N1     Select direct mode.
\N2     Select reliable link mode.
\N3     Select auto reliable mode.
\N4     Force LAMP mode.
\N5     Force MNP mode.

+ MS    Select modulation, (select data speed)

 Error Correction Commands

%C0     Disable data compression.
%C1     Enable MNP 5 data compression.
%C2     Enable V. 42 bis data compression.
%C3     Enable both V. 42 bis and MNP 5 compression.
\A0     Set maximum block size in MNP to 64.
\A1     Set maximum block size in MNP to 128.
\A2     Set maximum block size in MNP to 192.
\A3     Set maximum block size in MNP to 256.
\Bn     Send break of x 100 ms.
\L0     Use stream mode for MNP.
\L1     Use block mode for MNP.
\N1     Select direct mode.
\N2     Select reliable link mode.
\N3     Select auto reliable mode,
\N4     Force LAMP mode.
\N5     Force MNP mode.
\V0     Single line connect messages are controlled by X, W & S95 commands.
\V1     Connect messages are displayed in single line format.  

Voice Commands

#BDR    Select baud rate (turn off autobaud).
#CLS    Select data, fax. or voice.
#MDL?   Identify model.
#MFR?   Identify manufacturer.
#REV?   Identify revision level.
#TL     Audio output transmit level.
#VBQ?   Query buffer size.
#VBS    Bits per sample.
#VBT    Beep tone timer.
#VCI?   Identify compression method.
#VGT    Set playback volume in the command state.
#VLS    Voice line select.
#VRA    Ringback goes away timer (originate).
#VRN    Ringback never came timer (originate).
#VRX    Voice receive mode.
#VSD    Enable silence deletion (no function; command response only).
#VSK    Buffer skid setting.
#VSP    Silence detection period (voice receive).
#VSR    Sampling rate selection.
#VSS    Silence detection tuner (voice receive).
#VTD    DTMF/tone reporting.
#VTM    Enable timing mark placement.
#VTS    Generate tone signals.
#VTX    Voice transmit mode.

Audio Span Commands

-SMS=X, Y, Z, T SELECT Commands

X=0, DATA MODE             =3, AUTO MODE (default)
 =2, AUDIOSPAN MODE 
Y: Minimum data speed with audio for audiospan 
Z: Maximum data speed with audio for audiospan 
T: Symbol rate
T=0: Auto selection (default) 
T=1: Reserve

Example:

AT-SMS=2, 4800, 9600 selects Audiospan mode, specifies minimum 4800bps and 
maximum 9600bps.

#VLS=   6: speaker phone

The AT#VLS setting must be issue prior to establishing Audio span connection
if a voice line other than the default handset desired.

FAX Class 1 Commands

+FCLASS=n Service class
+FAE=n    Data/fax auto answer
+FRH=n    Receive data with HDLC framing.
+FRM=n    Receive data.
+FRS=n    Receive silence.
+FTH=n    Transmit data with HDLC framing.
+FIM=n    Transmit data.
+FTS=n    Stop transmission and wait.

S-Register Summary

Register  Function                      Range   Units   Saved   Default

S0      Rings to Auto-Answer            0-255   rings   *       0
S1      Rings Counter                   0-255   rings           0
S2      Escape Character                0-255   ASCII   *       43
S3      Carriage Return Character       0-127   ASCII           13
S4      Line Feed Character             0-127   ASCII           10
S5      Backspace Character             0-255   ASCII           8
S6      Wait Time for Dial Tone         2-255   s       *       2
S7      Wait Time for Carrier           1-255   s       *       50
S8      Pause Time Dial Delay Modifier  0-255   s       *       2
S9      Carrier Detect Response Time    1-255   0.1s    *       6
S10     Carrier Loss Disconnect Time    1-255   0.1s    *       14
S11     DTMF Tone Duration              50-255  0.001s  *       95
S12     Escape Prompt Delay             0-255   0.02s   *       50
S13     Reserved
S14     General Bit Mapped Options Status -     -       *       138(8Ah)
S15     Reserved
S16     Test Mode Bit Mapped Options Status (&T) -              0
S17     Reserved
S18     Test Timer                      0-255   s       *       0
S19     Auto Sync Options               -       -               0
S20     Auto Sync HDLC Address          0-255   -       *       0
        or BSC Sync Character
S21     V.24/General Bit Mapped Options Status  -       *       4(04h)
S22     Speaker/Result Bit Mapped Options Status-       *       117
S23     General Bit Mapped                      -       *
S24     Sleep Inactivity Timer          0-255   s       *       0
S25     Delay to DTR Off                0-255  s or0.01s        5
S26     RTS-to-CTS Delay                0-255   0.01s           1
S27     General Bit Mapped              -       -       *
S28     General Bit-Mapped Options Status -     -       *       0
S29     Flash Dial Modifier Timer       0-255   10ms            0
S30     Disconnect Inactivity           0-255   10s             0
S31     General Bit-Mapped Options Status -     -       *       2
S32     XON Character                   0-255   ASCII           17(11h)
S33     XOFF Character                  0-255   ASCII           19(13h)
S34     Reserved                        -               -
S36     LAPM Failure Control            -       -       *       7
S37     Line Connection Speed           -       -       *       0
S38     Delay Before Forced Hang up     0-255   s               20
S39     Flow Control Bit Mapped Options Status  -       *       3
S40     General Bit-Mapped              -       -       *
S41     General Bit-Mapped Options Status -     -       *       3
S42-S45 Reserved
S46     Data Compression Control        -       -       *       138
S48     V.42 Negotiation Control        -       -       *       7
S80     Reserved
S82     Reserved
S86     Call Failure Reason Code        0-255   -               -
S91     PSTN Transmit Attenuation       0-15    dBm             11#
S92     Fax Transmit Attenuation Level  0-15    dBm             11#
S95     Result Code Message Control     -       -       *       0

* Register value may be stored in one of two user profile with the &W command.

# country independent


+MS -Select Modulation

This extended format command selects the modulation and, optionally, enables
or disables auto mode, specifies the lowest and highest connection rates,
selects m-law or A-law codec type, and enables or disables robbed bit
signaling generation (server modem) or detection (client modem)
using one to five sub parameters. The command format is:

+MS=<mode>[,[< auto mode >][,<min rate>][,<x_law>][,<rb_signaling>]]]]]]<CR>

NOTES:

1.  For 14400bps and lower speeds, the Nn command and S37 register can
alternatively be used,in which case the +MS sub parameters will modified
to reflect the Nn and S37=x settings.
Use of the Nn and S37=x commands is not recommended but is provided
for compatibility with existing communication software. (S37 is not updated
by the+ MS command.)

2.  Sub parameters not entered (enter a comma only or <CR> to skip the last
sub parameters remain at their current values.

Reporting Selected Options

The modem can send a string of information to the DTE consisting of selected
options using the following command:

+MS?

The response is:

+MS:<mod>,<automode>,<min_rate>,<max_rate>,<x_law>,<rb_signaling>

For example:

+MS:56,1,300,56000,0,0 (56k modem default values)
+MS:11,1,300,33600,0,0 (33.6k modem default values)


Reporting Supported Options

The modem can send a string of information to the DTE consisting of supported
options using the following command:

+MS=?

The response is:

+MS:(list of supported <mode> values),(list of supported <automode> values),
(list of supported<mim_rate>values),(list of supported <max_rate> values),
(list of supported<x_law>values),(list of supported<rb_signaling>values)

For example:

+MS:(0,1,2,3,9,10,11,56,64,69),(0,1),(300-33600),(300-56000),(0,1),(0,1) [56k]
+MS:(0,1,2,3,9,10,11,64,69),(0, 1),(300-33600),(300-33600),(0,1),(0,1)   [33.6k]


Suparameter Definitions

1.  <mode>= A decimal number which specifies the preferred modulation (auto mode
enabled) or the modulation (auto mode disabled) to use in originating or answering
a connection. The options are:
------------------------------------------------------------------------------
<mode>  Modulation      Possible Rates(bps)                    Notes
------------------------------------------------------------------------------
 0       V.21           300
 1       V.22           1200
 2       V.22 bis       2400 or 1200
 3       V.23           1200
 9       V.32           9600 or 4800
 10      V.32 bis       14400,12000,96000, 7200, or 4800
 11      V.34           33600,31200,28800,26400,24000,21600,
                        19200,16800,14400,12000,9600,7200,4800,
                        or 2400                                 Default 33.6k
 56      K56flex        56000,54000,52000,50000,48000,46000,
                        44000,42000,40000,3 8000,36000,34000,
                        32000                                   [56k only]
 64      Bell 103       300
 69      Bell212        1200
------------------------------------------------------------------------------
 NOTES:
 1. See optional <auto mode>,<mim rate>,and <maxrate> sub parameters.
 2. For V.23, originating modes transmit at 75 bps and receive at 1200 bps;
 answering modes transmit at 1200 bps and receive at 75 bps.
 The rate is always specified as 1200 bps.
------------------------------------------------------------------------------
The mode may also automatically switch to another modulation (auto mode),
subject to the following constraints:

    a.  The modem may not be able to automatically switch from the current
        modulation( specified by <mod>) to some other modulation.
        For example, there is no standard way to auto mode from Bell 103
        to V.23.

    b.  The DTE may disable auto mode operation (see<automode> below).
    c.  Tne DTE may constrain the range of modulations available by specifying
        the lowest and highest rates (see<min__rate> and <max_rate> below).

        2. <automode> is an optional numeric value which enables or disables
        automatic modulation negotiation using V. 8 bis /V. 8 or V. 32 bis
        Annex A.

        The options are:

<auto mode>          Option Selected                            Notes

         0           Automode disabled
         1           Automode enabled using V.8 bis/v.8
                     or V.32 Annex A                            Default 


 The default values is 1,which enables automode. Note, however, there are
 modulations for which there is no automatic negotiation, e. g.. Bell 212
 (<mode>=69).
 For <automode>=0 (autornode disabled, i.e., fixed modulation):

 a.     If<max_rate> is within the rates supported by the selected rate is
        that specified by <max_rate>, For example:

        + MS=10,0,0,1200,4800  selects V.32 bis 4800 bps fixed rate.

 b.     If<max_rate> is greater than the highest speed supported by the
        modulation specified by <mode>, the starting rate is the highest rate
        supported by the selected modulation. For example:

        + MS=10,0,2400,14400  selects V.32 bis 14400, 12000, 9600, 7200, or 4800 bps.

 c.     To emulate issuance of the NOS37=x command sequence to select fixed
        mode operation,specify the <max_rate> and <mim rate> both to be the
        (same) requested speed, and <mod> to be the modulation for that speed.
        For example:

        +MS=11,0,16800,16800  selects V.34 16800 bps fixed mode (no comparable
        S37 command).

        + MS=10, 0, 12000 selects V. 32 bis 12000 bps fixed mode (same as
        NOS37=10)

        For <automode>=1 (automode enabled, i.e., automatically selected speed
        and modulation):
        The modem connects at the highest possible rate in accordance with
        V. 8 bis/V. 8, or V. 32 bis
        Annex A If V. 8 bis/V. 8 is not supported by the remote modem.


 a.     If <max_rate> is greater than the highest rate supported by the
        modulation specified by <mode>, the modem automodes down from the
        highest rate of the selected modulation. For example:
        +MS=10,1,1200,24000 selects automoding Down from V.32 bis 14400bps.

 b.     To emulate issuance of the N1S37=x sequence command, specify the
 modulation

        +MS=11,1,1200,24000 selects automode starting at V.34 168000 bps
        (no comparable S37 command).

        +MS=9,1,300,12000 selects automode starting at V.32 bis 12000 bps
        (same as NS37=10).

 3.     <min_rate> is an optional number which specifies the lowest rate at
        which the modem may establish a connection. The value is decimal
        coded, in units of bps, e.g., 2400 bps. The default is 300 for 300 bps.

 4.     <max_rate> is an optional number which specifies the highest rate at
        which the modem may establish a connection. The value is decimal
        coded, in units of bps, e. g., 14400 bps.
        The default is 28800 for 28800 bps.

 5.     <x-law> is an optional number which specifies the codec type.
        The options are:

        0=m-Law

        1=A-Law

 6.     <rb_signaling> is an optional number which enables or disables
        robbed bit signaling generation in a sever modem or enables or
        disables robbed bit signaling detection in a client modem.
        The options are:

        0=Robbed bit signaling generation (server modem) or detection
        (client modem) disabled (default)
        1=Robbed bit signaling generation (server modem) or detection
        (client modem) enabled                                                                        

        Note that ATZ will reset the <rb_signaing> selection to 0 (disabled)

        Result Codes:

        OK      Valid subparameter string
        ERROR   Otherwise
