Computers : Fixes & Help : Modem

AT Commands

Basic, Diagnostics and Main AT Commands

Note : - This is only a brief outline of AT Commands and may not work for all manufacturers, please refer to your modem manual for further information.

Basic

Command  

Command function

%C0

Data compression disable

%C1

MNP5 enable

&C0

DCD Always On

&C1

Modem Controls DCD

&D0

Ignore DTR

&D1

On-Line Command Mode

&D2

DTE Controls DTR

&D3

Reset modem

&F

Load Factory Defaults

&F0

Load Factory 0, no FC

&F1

Load Factory 1, HW FC

&F2

Load Factory 2, SW FC

&Q1

Synch mode 1

&Q2

Synch mode 2, dial stored number when DTR makes transition

&Q3

Synch mode 3, manual dialing

&Q4

Reserved

&Q5

Reliable Asynch mode

&Q6

Normal Asynch mode

&S0

DSR Always On

&S1

Modem Controls DSR

X1

Dial straight through without waiting for dial tone.

X2

Wait for tone before dialing

X3

Ignore dial tone

X4

Wait for tone, detect dialtone and report busy

Diagnostics

Command  

Command function

ATQ0V1E0

Initializes the query.

AT+GMM

Model identification (ITU V.250 recommendation is not supported by all modems).

AT+FCLASS=?

Fax classes supported by the modem, if any.

AT#CLS=?

Shows whether the modem supports the Rockwell voice command set.

ATIn

Displays manufacturer's information for n = 1 through 7.
This provides information such as the port speed, the result of a checksum test, and the model information.
Check the manufacturer's documentation for the expected results.

Main

Command  

Command function

ATA

Answer

ATD

Dial

ATH

Hang up

ATZ

Reset