39
CHAPTER 4: AT Commands, S-Registers, and Result Codes
You can issue several commands in one line, in what is called a command string.
The command string begins with
AT
and ends when you press ENTER. Spaces to
separate the commands are optional; they are ignored by the command
interpreter. The most familiar command string is the
initialization string
, which is
used to configure the modem when it is turned on or reset, or when your
communications software calls another modem.
AT C
OMMAND
S
UMMARY
Command:
AT
Attention Code
Values:
n/a
Description:
The attention code precedes all command lines
except
A/
,
A:
, and escape sequences.
Command:
ENTER Key
Values:
n/a
Description:
Press the Enter (Return) key to execute most
commands.
Command:
A
Answer
Values:
n/a
Description:
Answer call before final ring.
Command:
A/
Repeat Last Command
Values:
n/a
Description:
Repeat the last command string. Do not precede
this command with
AT
. Do not press Enter to
execute.
Command:
B
n
Communication Standard Setting
Values:
n
=0–3, 15, 16
Default:
1 and 16
Description:
B0
Select ITU-T V.22 mode when modem is at
1200 bps.
B1
Select Bell 212A when modem is at 1200 bps.
B2
Deselect V.23 reverse channel (same as
B3
).
B3
Deselect V.23 reverse channel (same as
B2
).
B15
Select V.21 when the modem is at 300 bps.
B16
Select Bell 103J when the modem is at 300 bps.
