B-2 APPENDIX B: AT COMMANDS, REGISTERS, AND RESULT CODES
&D DTR control (AT &D0) &D0 causes digital modem to ignore DTR
from host.
&D1 causes digital modem to enter
command state on detecting on-off
transition of DTR.
&D2 causes digital modem to hang up
current calls upon on-off transition of DTR
and prepares serial port to accept AT
command at any speed (default).
E AT command echo (AT E0) E0 disables the echo of AT commands
back to the host computer.
E1 enables the echo of AT commands to
the host computer (default).
&F Restore factory defaults (AT &F) Restores all factory default settings.
H Hang up (AT H) Hangs up the current connections.
I Identification (AT I0) I0 displays the product and options ID.
I1 displays the flash memory checksum.
I4 displays the modem product code,
precomputed checksum, firmware
revision number, model, interface type,
country code, and data pump model.
O Enter connect state (AT O) Causes the digital modem to go out of
command mode into on-line mode.
Q Result code control (AT Q0) Q0 enables the output of result codes
(default).
Q1 disables the output of result codes.
Q2 disables the output of result codes in
answer mode only.
\Q Serial port flow control (AT \Q1) \Q0 disables flow control.
\Q1 enables bidirectional XON/XOFF
software flow control.
\Q3 enables bidirectional RTS/CTS
hardware flow control (default).
%R Read all S registers (AT %R) Provides an output list of all S registers.
SN? Read configuration register
(AT S60?)
Reads a specific S register setting.
SN= Write configuration register
(AT S60=64)
Writes to a specific S register.
(continued)
Table B-1 AT Command Set Summary (continued)
Command Function (Example) Description