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Chapter 9, At command set summary – ZyXEL Communications 2864 User Manual

Page 111

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9–1

Chapter 9

AT COMMAND SET SUMMARY

An

AT

command is a command issued by the computer/terminal to the modem

through the asynchronous computer-modem interface in asynchronous data for-
mat.

AT

commands control the modem's behavior and actions. To send an

AT

command from a computer to the modem, you must be running a communication
software and the modem must be in command state.

An

AT

command prefix (ATtention) precedes each command line, except in the

case of

A/

,

A>

, and

+++

.

A/

re-executes the last command once.

A>

re-executes

the last command once, and repeats the last call up to 9 times until aborted by
physically pressing any key on the keyboard or front panel or until a successful con-
nection with a remote modem has been made. These commands are not preceded
by

AT

or followed by more characters. Up to 40 commands can be entered in a

command line with a single

AT

prefix. Be sure to either use all capital letters (AT)

or none at all (at).

+++ is the escape sequence code that is entered in data state to return the modem
to command state. The modem will accept

AT

commands only while it is in com-

mand state.

Basic AT Command Set

A list of the basic AT command set follows. Each command should be entered after
an AT prefix. A plus sign (

+) placed before a command in the list indicates that it is

a default setting.

A

Goes on-line in answer mode. (See also

S39b2

,

S43b6

)

+

B0

Selects ITU-T V.22 for 1200 bps communication. (Default)

B1

Selects Bell 212A for 1200 bps communication.

D

Enters originate mode, dials the number that follows; attempts to go
on-line. (See also

S35b4

,

S38b0

)

Digits and modifiers that can be used with the

D

command:

0-9

,

#

,

*

Digits for dialing.

P

Pulse dial.

T

Tone dial.

W

Wait for a second dial tone. (See also

S6

)