Standard Hayes Compatible AT Command Set

Section 3

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Bolded text indicates default setting (&F)

%C0

%C1

%C1

%C3
Disables data compression

Enables MNP5 compression

Enables V.42bis compression

Enables both MNP5 and V.42bis compression

%E0

%E1

%E2

%E3
Disables line-quality monitoring and auto-retraining

Enables monitoring and retraining

Enables monitoring and fallback/fall forward

Enables monitoring, retraining and fast hang up

%L
Reports received signal level in -DBm
%Q
Reports line signal quality
\A0

\A1

\A2

\A3
64 character maximum MNP block size

128 character maximum MNP block size

192 character maximum MNP block size

256 character maximum MNP block size

\Bn
In non-error correction mode, transmits line break to remote modem in 100ms units (1-9 with 3 as default)
\G0

\G1
Disables XON/XOFF (modem to modem) flow control

Enables XON/XOFF (modem to modem) flow control

\Kn
Defines break type
\N0

\N1

\N2

\N3

\N4

\N5
Normal data link with speed buffering; no error correction

Selects serial interface; same as &Q0

Selects reliable (error correction) mode (first LAPM, then MNP)

Selects auto-reliable mode (LAPM, MNP, Normal)

LAPM error correction only

MNP error correction only

\V=0

\V=1

.
Disables Single Line Connect Message

Enables Single Line Connect Message, where the format is: CONNECT <DTE speed></Modulation></Protocol></Compression></Line speed>

-SDR=0

-SDR=1

-SDR=2

-SDR=3

-SDR=4

-SDR=5

-SDR=6

-SDR=7
Disables Distinctive rings Ring Cadence

Enables Type 1, 2 secs ON, 4 secs OFF

Enables Type 2, 0.8 sec ON, 0.4 sec OFF, 0.8 sec ON, 4.0 sec OFF

Enables Type 1 & 2, 0.4 sec ON, 0.2 sec OFF, 0.4 sec ON, 0.2 sec ON

Enables Type 3. 0.8 sec ON 4.0 sec OFF

Enables Type 1 & 3

Enables Type 2 & 3

Enables Type 1, 2 & 3

$$RO

$$R1
.

.

.

.
Disables Distinctive Ring

Enables Distinctive Ring, Cadences are:

A = 2.0 secs ON, 4.0 secs OFF

B = 0.8 sec ON, 0.4 sec OFF, 0.8 sec ON, 4.0 secs ON

C = 0.4 sec ON, 0.2 sec OFF, 0.4 sec ON, 0.2 sec OFF, 0.8 sec ON, 4.0 secs OFF

D = 0.3 sec ON, 0.2 sec OFF, 1.0 sec ON, 0.2 sec OFF, 0.3 sec ON, 4.0 secs OFF

-K0

-K1

-K2
Disables V.42 LAPM to MNP10 conversion

Enables V.42 LAPM to MNP10 conversion

Enables V.42 LAPM to MNP10 conversion: inhibits MNP Extended Services initiation during V.42 LAPM anser mode detection

-Q0

-Q1
Disables MNP10 fallback to 2400 bps.

Enables MNP10 fallback to 2400 bps

-SEC=0

-SEC=1
Disables MNP10-EC operation

Enables MNP10-EC operation

:E0

:E1
Disables V.32 compromise equalizer

Enables V.32 compromise equalizer

+MS=<mod>,<automode>,<min_rate>,<max_rate>

Selects modulation: optionally enables or disables automatic modulation negotiation with the remote modem or faxmodem; optionally sets minimum and/or maximum rates

<mod>

0

1

2

3

9

10

11

.

56

.

.

64

69
Selects Modulation

V.21

V.22

V.22bis

V.23

V.32

V.32bis

V.34

.

K56Flex

.

.

Bell 103

Bell 212
Possible speeds

300

1200

2400, 1200

1200

9600, 4800

14400, 12000, 9600, 7200, 4800

33600,31200,28800,26400,24000,19200,

16800,14400,12000,9600,7200,4800,2400

56000,54000,52000,50000,48000,46000,

44000,42000,40000,38000,36000,34000,

32000, (downstream speed only)

300

1200

<automode>

1

0
Enables or disables automatic modulation negotiation with the remote modem

Enables (equivalent to N1 command)

Disables (equivalent to N0 command)

.

.

.

<min_rate>
300
(See possible rates above)
<max_rate>
33600
(See possible rates above)
Example
+MS=11,1,300,28800
Sets mode 11, enables auto modulation and sets the min/max baud rate to 300 and 28800.