AT Command Set and S-Registers
4-2
Issue 2 May 1995
Table 4-1. AT Command Reference (1 of 18)
AT
Command Description
+++
ESCAPE SEQUENCE
The escape sequence allows the modem to exit Data mode
and enter online Command mode. For more information on
using this command, see page 3-9.
A/
REPEAT LAST COMMAND
This command re-executes the last ‘AT’ command string
stored in the command buffer. The A/ command is the only
command not preceded by ‘AT’ and ended by a carriage
return.
A
ANSWER COMMAND
This command allows the modem to go off-hook and answer
an incoming call.
B
n
CCITT/BELL MODE
This command selects a CCITT or Bell communications
standard. When CCITT V.23 is selected, this command also
selects the send and receive data rates.
For more information, refer to the %B command,
S-Registers S76 and S78, and Appendix E,
Advanced
Modem Concepts.
B0
Selects CCITT V.22 when the modem is at
1200 bps, and CCITT V.21 when the modem
is at 300 bps.
B1
Selects Bell
212A when the modem is at
1200 bps, and Bell 103 when the modem is at
300 bps.
B2
Selects CCITT V.23. Modem receives at 1200 bps
and transmit at 75 bps when in originate mode.
Modem receives at 75 bps and transmits at 75 bps
when in answer mode.
B3
Selects CCITT V.23. Modem receives at 75 bps and
transmits at 75 bps when in originate mode. Modem
receives at 1200 bps and transmit at 75 bps when in
answer mode.
