25
C
HAPTER
5
C
OMMAND
R
EFERENCE
This chapter includes all commands, S-Registers supported by the modem. Before using the
commands, make sure your communications software package provides the function of
operating the modem through its interna1 commands. If your software does not support the
function, ignore this chapter.
More than one command can be placed on a single line and, if desired, separated with spaces
for readability. Once the carriage return (
Enter
) key is pressed, the command line will be
executed. A line with no carriage return is ignored. If you come across terms that you don't
understand, consult the glossary. Words in
boldface type
are command names, commands, or
default settings. Carriage returns (Enter) are noted with <CR> or [ENTER]; this does not mean
to enter these characters literally; but instead to press the
Enter
key.
The modem accepts either upper or lower case characters in the command line and ignores any
space within or between commands. Typing errors can be corrected with the
Backspace
key.
Exceptions are noted in the description of specific commands.
Variables (r and x) are listed in italics. Punctuation symbols (
, ; ! @
) use as dial modifiers are
listed alphabetically according to their English names at the beginning of Section 5.2 where
two commands are separated by a slash, either command will have the same effect. For
example, if the command is listed as
B0/B
, issuing either
B0
or
B
will have the same effect.
Note:
Except for the
A
/ command and the
+ + +
escape command described in Section 5.3, all
commands must be prefixed with the attention code
AT
. For instance, the
A
command (below)
would be entered as: "
AT A <CR>
". Without the
AT
prefix, the command line cannot be
executed. Once entered, AT cannot be deleted with the
Backspace
or
Delete
keys.
5.1 AT Commands
5.1.1 Basic Command Set
A
Go On-line in Answer Mode (For FAX Mode)
This command instructs the modem to go off-hook immediately and then make a handshake with the
remote modem. Handshaking is not available during leased line operation.
Bn
Select Protocol to ITU-V.22 or Bell 212A
B0/B
Selects ITU-V.22 protocol once the command line prefix
AT
has been entered at the 1200 bps
data rate.
B1
Selects BELL 212A protocol once the command line prefix
AT
has been entered at the 1200 bps
data rate. (Default)
D
Go On-line in Originate Mode
D
instructs the modem to go off-hook immediately and automatically dial the number contained in the
dial string following
D
. The dial string may contain any of the dial modifiers contained in the following
section. The
D
command without a dial string is usually used to switch from voice conversation to data
communication or to call a remote modem in leased-line operation mode.
En
Command Echo
