Command

Syntax

Function

Default

+++

+++

Escape to online command mode (not preceded by AT)

/

/

Pause (not preceded by AT)

125 ms

A

ATA

Answer manually

A/

A/

Repeat last command (not preceded by AT)

D

ATD

Dial

 n   Phone #, 0 through 9

DT

ATDT

 T   Tone dial

DP

ATDP

 P   Pulse dial

DR

ATDR

 R   Call an originate-only modem

DTnWn

ATDTnWn

 W   Wait for second dial tone (X2, X4)

DTWn@

ATDTWn@

 @   Wait for answer (X3, X4)

DTn!n

ATDTn!n

 !   Flash switch hook

DTn#n

ATDTn#n

 #   Auxiliary tone dial digit

DTn,n

ATDTn,n

 ,   Pause in dialing (S8)

2 seconds

DTn*n

ATDTn*n

 *   Auxiliary tone dial digit

DTn;n

ATDTn;n

 ;   Stay in command mode after dialing

DTn$n

ATDTn$n

 $   Wait for calling card bong

DTn&n

ATDTn&n

 &   Wait for calling card bong

DTn"n

ATDTn"n

 "   Set quote mode for the following

D$

ATD$

Display a list of dial commands

DL

ATDL

Redial last number

DL?

ATDL?

Display last dialed number

DSn

ATDSn

Dial stored number

E0

ATE0

Turn command echo off

E1

ATE1

Turn command echo on

X

F0

ATF0

Turn online echo on

F1

ATF1

Turn online echo off

X

H0

ATH0

Hang up (go on-hook)

H1

ATH1

Pick up (go off-hook)

I0

ATI0

Display the 4-digit product code

I1

ATI1

Display the checksum

I2

ATI2

Display the RAM test results

I3

ATI3

Display the firmware version

I4

ATI4

Display the current modem settings

I5

ATI5

Display user profiles

I7

ATI7

Display the product configuration

I8

ATI8

Display black list screen

I10

ATI10

Display VXD configuration screen

I11

ATI11

Display V.34 link screen

L0

ATL0

Set modem speaker volume off

L1

ATL1

Set modem speaker volume on (low)

L2

ATL2

Set modem speaker volume on (medium)

X

L3

ATL3

Set modem speaker volume on (high)

M0

ATM0

The modem's speaker is always off

M1

ATM1

The modem's speaker is on until a connection is made

X

M2

ATM2

The modem's speaker is always on

M3

ATM3

The modem's speaker is off during dialing, and on after dialing until the connection is made

O0

ATO0

Return to online mode

O1

ATO1

Return to online mode and retrain (automatically return to the highest speed)

S$

ATS$

Display the list of S-register settings

Sr=n

ATSr=n

Set S-Register "r" to "n"

Sr?

ATSr?

Display the value of S-Register "r"

V0

ATV0

Display result codes in numeric form

V1

ATV1

Display result codes in verbose form (words)

X

X0

ATX0

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

X1

ATX1

Report basic call progress result codes and the connect rates-OK, CONNECT, RING, NO CARRIER (also, for busy, if enabled, and dial tone not detected), NO ANSWER, CONNECT XXXX and ERROR

X2

ATX2

Report basic call progress result codes and the connect rates i.e., OK, CONNECT, RING, NO CARRIER (also, for busy, if enabled), NO DIAL TONE, NO ANSWER, CONNECT XXXX and ERROR

X3

ATX3

Report basic call progress result codes and connection rate i.e., OK, CONNECT, RING, NO CARRIER, NO ANSWER, CONNECT XXXX, BUSY and ERROR

X4

ATX4

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

X

Y0

ATY0

On the next reset, use &W settings

X

Y1

ATY1

On the next reset, use &W1 settings

Y2

ATY2

On the next reset, use &F settings

Y3

ATY3

On the next reset, use &F1 settings

Y4

ATY4

On the next reset, use &F2 settings

Z0

ATZ0

Reset the modem according to the settings of ATY

Z1

ATZ1

Reset the modem and use &W settings

Z2

ATZ2

Reset the modem and use &W1 settings

Z3

ATZ3

Reset the modem using &F settings and load factory default profile 1

Z4

ATZ4

Reset the modem using &F1 settings and load factory default profile

Z5

ATZ5

Reset the modem using &F2 settings and load factory default profile 2

$

AT$

Display the list of AT commands

&$

AT&$

Display the list of ampersand commands

&A0

AT&A0

Disable data compression result codes

&A1

AT&A1

Enable data compression result codes

&A2

AT&A2

Enable modulation result codes

&A3

AT&A3

Enable data compression result codes and add V.42bis and MNP 5 protocol indicators

X

&B0

AT&B0

Use a floating DTE speed

X

&B1

AT&B1

Use a fixed DTE speed

&B2

AT&B2

Use a fixed DTE speed when using data compression

&C0

AT&C0

Carrier detect is always on

&C1

AT&C1

Carrier detect is controlled by the modem

X

&D0

AT&D0

Ignore DTR

&D1

AT&D1

Use online command mode

&D2

AT&D2

DTE controls DTR

X

&D3

AT&D3

DTE controls DTR and reset

&F0

AT&F0

Set the factory profile that uses hardware (RTS/CTS) flow control (this is the active profile when the modem is shipped)

&F1

AT&F1

Set the factory profile that uses hardware (RTS/CTS) flow control

&F2

AT&F2

Set the factory profile that uses software (XON/XOFF) flow control

&G0

AT&G0

No guard tone

X

&G1

AT&G1

Use 550 Hz guard tone

&G2

AT&G2

Use 1800 Hz guard tone

&H0

AT&H0

Flow control for transmitted data - Disable flow control

&H1

AT&H1

Flow control for transmitted data - Enable hardware flow control (RTS/CTS)

X

&H2

AT&H2

Flow control for transmitted data - Enable software (XON/XOFF)

&H3

AT&H3

Flow control for transmitted data - Enable both software and hardware flow control

&I0

AT&I0

Flow control for received data - Disable flow control

X

&I1

AT&I1

Flow control for received data - send XON/XOFF signals to modems on both ends

&I2

AT&I2

Flow control for received data - send XON/XOFF signals to your modem only

&I3

AT&I3

HP Eng/Ack in Host mode

&I4

AT&I4

HP Eng/Ack in Terminal Mode

&I5

AT&I5

Flow control for received data - If error correction is used, send XON/XOFF signals to your modem only; if data compression is not used, look for incoming XON/XOFF

&K0

AT&K0

Disable data compression

&K1

AT&K1

Enable data compression (V.42bis, MNP 5, NONE)

X

&K2

AT&K2

Enable data compression (forces V.42bis)

&K3

AT&K3

Use selective data compression

&M0

AT&M0

Disable error correction in 1200 bps and faster transfers

&M4

AT&M4

Allow V.42 or MNP error correction in 1200 bps and faster transfers

X

&M5

AT&M5

Allow either V.42 or MNP error correction in 1200 bps and faster transfers

&N0

AT&N0

Highest link speed

X

&N1

AT&N1

Link Speed - 300 bps

&N2

AT&N2

Link Speed - 1200 bps

&N3

AT&N3

Link Speed - 2400 bps

&N4

AT&N4

Link Speed - 4800 bps

&N5

AT&N5

Link Speed - 7200 bps

&N6

AT&N6

Link Speed - 9600 bps

&N7

AT&N7

Link Speed - 12000 bps

&N8

AT&N8

Link Speed - 14400 bps

&N9

AT&N9

Link Speed - 16800 bps

&N10

AT&N10

Link Speed - 19200 bps

&N11

AT&N11

Link Speed - 21600 bps

&N12

AT&N12

Link Speed - 24000 bps

&N13

AT&N13

Link Speed - 26400 bps

&N14

AT&N14

Link Speed - 28800 bps

&N15

AT&N15

Link Speed - 31200 bps

&N16

AT&N16

Link Speed - 33600 bps

&N17

AT&N17

Link Speed - 33333 bps

&N18

AT&N18

Link Speed - 37333 bps

&N19

AT&N19

Link Speed - 41333 bps

&N20

AT&N20

Link Speed - 42666 bps

&N21

AT&N21

Link Speed - 44000 bps

&N22

AT&N22

Link Speed - 45333 bps

&N23

AT&N23

Link Speed - 46666 bps

&N24

AT&N24

Link Speed - 48000 bps

&N25

AT&N25

Link Speed - 49333 bps

&N26

AT&N26

Link Speed - 50666 bps

&N27

AT&N27

Link Speed - 52000 bps

&N28

AT&N28

Link Speed - 53333 bps

&N29

AT&N29

Link Speed - 54666 bps

&N30

AT&N30

Link Speed - 56000 bps

&R1

AT&R1

Ignore RTS

&R2

AT&R2

Receive to DTE/RTS high

X

&S0

AT&S0

Data Set Ready (DSR) is always on

X

&S1

AT&S1

Data Set Ready (DSR) signals that the modem is ready to send data

&U0

AT&U0

Variable link rate floor

X

&U1

AT&U1

Minimum link rate-300 bps

&U2

AT&U2

Minimum link rate-1200 bps

&U3

AT&U3

Minimum link rate-2400 bps

&U4

AT&U4

Minimum link rate-4800 bps

&U5

AT&U5

Minimum link rate-7200 bps

&U6

AT&U6

Minimum link rate-9600 bps

&U7

AT&U7

Minimum link rate-12000 bps

&U8

AT&U8

Minimum link rate-14400 bps

&U9

AT&U9

Minimum link rate-16800 bps

&U10

AT&U10

Minimum link rate-19200 bps

&U11

AT&U11

Minimum link rate-21600 bps

&U12

AT&U12

Minimum link rate-24000 bps

&U13

AT&U13

Minimum link rate-26400 bps

&U14

AT&U14

Minimum link rate-28800 bps

&U15

AT&U15

Minimum link rate-31200 bps

&U16

AT&U16

Minimum link rate-33600 bps

&U17

AT&U17

Minimum link rate-33333 bps

&U18

AT&U18

Minimum link rate-37333 bps

&U19

AT&U19

Minimum link rate-41333 bps

&U20

AT&U20

Minimum link rate-42666 bps

&U21

AT&U21

Minimum link rate-44000 bps

&U22

AT&U22

Minimum link rate-45333 bps

&U23

AT&U23

Minimum link rate-46666 bps

&U24

AT&U24

Minimum link rate-48000 bps

&U25

AT&U25

Minimum link rate-49333 bps

&U26

AT&U26

Minimum link rate-50666 bps

&U27

AT&U27

Minimum link rate-52000 bps

&U28

AT&U28

Minimum link rate-53333 bps

&U29

AT&U29

Minimum link rate-54666 bps

&U30

AT&U30

Minimum link rate-56000 bps

&W0

AT&W0

Write (store) user profile 0 to memory

&W1

AT&W1

Write (store) user profile 1 to memory

&Zn=s

AT&Zn=s

Store phone number

&Zn?

AT&Zn?

Display phone number

Register

Function

Range

Default

S0

Number of rings before the modem auto-answers a call. If set to 0, auto-answer is disabled and manual answer is in effect

0-255

0 rings

S1

Counts and logs the number of rings

0-255

0 rings

S2

Designates the ASCII character used to indicate an escape character (refer to an ASCII character conversion chart)

0-127

ASCII 43

S3

Designates the ASCII character used for carriage returns (refer to an ASCII character conversion chart)

0-127

ASCII 13

S4

Designates the ASCII character used for line feeds (refer to an ASCII character conversion chart)

0-127

ASCII 1

S5

Designates the ASCII character used for backspaces

0-127

ASCII 8

S6

Dial tone wait time; if AT command X is set to X2 or X4, the modem ignores this register and dials as soon as it detects a dial tone

2-255

2 seconds

S7

Carrier wait time

1-255

60 seconds

S8

Pause in dialing time (comma in dialing string)

0-255

2 seconds

S9

Carrier detect validation time (1/10 second)

1-255

6

S10

Delay time between lost carrier and hangup; if S1=255, the modem will not hang up when the carrier is lost; dropping DTR hangs up the modem (1/10 second)

1-255

7

S11

Duration of the touchtone dialing tone spacing

50-255

70 ms

S12

Guard time for the escape code (1/50 second)

0-255

50

S13

Bitmapped register. Selects the bit(s) you want on and sets S13 to the total of the values in the Value column. For example, ATS13.0=17 enables bit 0 (value 1) and bit 4 (value 16)

0-255

0

1 = Reset on DTR loss

2 = Reduced non-ARQ transmit buffer

4 = Set DEL=backspace

8 = Do DS0 on DTR

16 = Do DS0 on Reset

128 = Escape code hangup

S15

Bitmapped register.

0-255

0

1 = MNP/V.42 disabled in V.22

2 = MNP/V.42 disabled in V.22bis

4 = MNP/V.42 disabled V.32, V.34

8 = Disable MNP handshake

16 = Disable MNP level 4

32 = Disable MNP level 3

64 = Unusual MNP incompatibility

128 = Disable V.42

136 = Disable V.42 detection phase

S16

Bitmapped test register. 2 = Dial test

2

0

S18

Test timer for AT command &T; when AT&T=0 the timer is disabled.

0-255

0 sec

S19

Duration for inactivity timer; S19=0 disables the timer

0-255

0

S21

Sets error correction break length (1/100 second)

0-255

10

S22

Designates the ASCII character code for XON

0-127

ASCII 17

S23

Designates the ASCII character code for XOFF

0-127

ASCII 19

S25

DTR debounce time indicator (1/100 second)

0-255

5

S27

Bitmapped register.

-

0

1 = V.21 mode

2 = Disable TCM

4 = Disable V.32

8 = Disable 21Hz

16 = Enable V.23 fallback

32 = Disable V.32bis

128 = Software compatibility mode

S28

V.32 Handshake Time (1/10 second)

0-255

8

S29

V.21 Answer Mode Fallback Timer

0-255

20

S32

Connection bitmapped operations.

-

2

1 = V.8 call indicate enable

2 = Enable V.8 mode*

8 = Disable V.34 modulation

16 = Disable V.34+ modulation

32 = Disable X2 modulation*

64 = Disable V.90 modulation

* Be sure to enable V.8 mode when disabling X2

S33

V.34 and V.34+ connection setup bitmapped control flags.

-

32

1 = Disable 24 symbol rate

2 = Disable 2743 symbol rate

4 = Disable 28 symbol rate

8 = Disable 3 symbol rate

16 = Disable 32 symbol rate

32 = Disable 3429 symbol rate

128 = Disable shaping

S34

V.34 and V.34+ connection setup bitmapped control flags

-

0

16 = Disable nonlinear coding

32 = Disable transmit level deviation

64 = Disable preemphasis

128 = Disable precoding

S38

Delay before forced hangup (optional)

0-255

0

Numeric

Verbose

X0

X1

X2

X3

X4

0

OK

X

X

X

X

X

1

CONNECT

X

X

X

X

X

2

RING

X

X

X

X

X

3

NO CARRIER

X

X

X

X

X

4

ERROR

X

X

X

X

X

5

CONNECT 1200

X

X

X

X

6

NO DIAL TONE

X

X

7

BUSY

X

X

8

NO ANSWER

X

X

(requires @ in dial string; replaces NO CARRIER)

10

CONNECT 2400

X

X

X

X

11

RINGING

X

X

X

X

13

CONNECT 9600

X

X

X

X

15

CONNECT 1200

X

X

X

X

18

CONNECT 4800

X

X

X

X

20

CONNECT 7200

X

X

X

X

21

CONNECT 12000

X

X

X

X

25

CONNECT 14400

X

X

X

X

43

CONNECT 16800

X

X

X

X

85

CONNECT 19200

X

X

X

X

91

CONNECT 21600

X

X

X

X

99

CONNECT 24000

X

X

X

X

103

CONNECT 26400

X

X

X

X

107

CONNECT 28800

X

X

X

X

151

CONNECT 31200

X

X

X

X

155

CONNECT 33600

X

X

X

X

180

CONNECT 33333

X

X

X

X

184

CONNECT 37333

X

X

X

X

188

CONNECT 41333

X

X

X

X

192

CONNECT 42666

X

X

X

X

196

CONNECT 44000

X

X

X

X

200

CONNECT 45333

X

X

X

X

204

CONNECT 46666

X

X

X

X

208

CONNECT 48000

X

X

X

X

212

CONNECT 49333

X

X

X

X

216

CONNECT 50666

X

X

X

X

220

CONNECT 52000

X

X

X

X

224

CONNECT 53333

X

X

X

X

228

CONNECT 54666

X

X

X

X

232

CONNECT 56000

X

X

X

X

Adaptive dialing

X

X

X

Wait for 2nd Dial Tone (W)

X

X

Wait for Answer (@)

X

X

Fast Dial

X

X