Standard Hayes Compatible AT Command Set

Section 1

On to section 2

On to section 3

Bolded text indicates default setting (&F)

A
Answers incoming calls immediately
B0

B1
Uses V.22 Connection at 1200 BPS

Uses Bell 212A connection at 1200BPS

Dn

DL

DP

DT

DR

S=0-3
Dials telephone number n (Commonly called dial string)

Dials last number dialed.

Uses pulse dialing

Uses tone dialing

Command accepted but no action taken

Dial one of four numbers stored with command &Zn

!

W
Goes on hook (hangs up, time specified in S29)

Waits for dial tone

@

&

,(comma)

; (semi colon)

^
Waits for at least 5 seconds of silence

Waits for credit card dialing tone (bong tone)

Pauses during dial as specified in register S8 (default = 2 secs)

Returns to command mode after dialing (put after dial string)

Turn on calling tone (data only)

E0

E1
Command characters not echoed

Command characters echoed

H0

H1
Forces modem to hang up

Forces modem off hook

I0

I1

I2

I3

I4

I5

I6

I98

I99
Returns product code (for example 33600)

Returns ROM checksum

Computes checksum, compares value in ROM and returns OK or ERROR

Returns firmware revision code

Returns modem identifier strings

Returns country code

Returns data pump model and revision code

Returns modem features description

Returns modem features in hex bitmap

L1

L2

L3
Low speaker volume

Medium speaker volume

High speaker volume

M0

M1

M2

M3
Speaker always off

Speaker on until carrier detected

Speaker always on

Speaker off during dialing and then on until carrier detected

N0

N1
Disables auto-mode (automatic modulation negotiation), uses connection speed specified in S37. (Equivalent to +MS <automode> set to 0)

Enables auto mode. (Equivalent to +MS <automode> set to 1)

O0

O1
Enters data mode

Enters data mode and retrains modem to phone line condition

P
Pulse dialing until T command
Q0

Q1
Enables responses to computer (DTE)

Disables responses to computer

Sn

Sn=v

Sn?
Establishes S register n as the default register

Sets register n to value v

Returns the value of register n

T
Tone dialing until P command
V0

V1
Send numeric (terse) response

Send word (verbose) responses

W0

W1

W2
Reports DTE (computer to modem) speed only

Reports DCE (modem to modem) , error correction protocol and DTE speed

Reports DCE (modem to modem) speed only

X0

X1

X2

X3

X4
Sends OK, CONNECT, RING, NO CARRIER, ERROR and NO ANSWER

Sends X0 messages plus CONNECT speed

Sends X1 messages plus NO DIALTONE

Sends X1 messages plus BUSY

Sends all responses

Y0

Y1
Disables long space disconnect

Enables long space disconnect; with error correction, hangs up after 1.6 second signal break; without error correction, sends 4 second space before hanging up.

Z0

Z1
Resets modem to profile 0 (see &W0)

Resets modem to profile 1 (see &*W1)