A-1
APPENDIX A. "AT" COMMAND SUMMARY
This manual does not attempt to be a primer on
the "AT" command set. The commands are
therefore only summarized below. For most
applications, the modem commands are issued
automatically by the PC208 software. The
commands apply only when the modem is used
as an originate modem, which is not the primary
use of this modem. Except as noted, all
commands begin with "AT" and end with
carriage return. As an example, the command
ATDT5551212 followed by carriage return will
tone dial the number that follows the ATDT,
then go on-line and wait up to 30 seconds for
the remote modem carrier. If the carrier is
detected, the result code 1 will be returned,
otherwise the result code 3 will be returned, and
the modem will return to the command mode.
COMMANDS:
AT
Prefix to all commands (except /A)
A/
Repeat last command (not followed by
carriage return)
D
Dial
P
Pulse
T
Tone
0..9
Telephone number digits
W
Wait for another dial tone
;
Return to command state after dialing
,
Pause
Z
Reset to default settings
A
Answer without ring
H
Hang up
O
Go to on-line state
COMMANDS TO CHANGE DEFAULT MODES:
R
Call an originate modem
B
CCITT mode
B1
BELL 212A mode
C
Carrier off
C1
Carrier on
E
Commands not echoed
E1
Commands echoed
F
Half duplex
F1
Full duplex
Q
Return result codes
Q1
Disable result codes
Sr?
What is the value in register r
Sr=n Set register r to value n
V
Digit result codes
V1
Word result codes
RESULT CODES:
0
OK
1
Connect
2
Ring
3
No Carrier
4
Error
REGISTERS:
S0
Rings before auto-answer (0..255)
S6
Wait for dial tone (2..255 seconds)
S7
Wait for remote carrier (1..255 seconds)
S8
Comma pause time (0..255 seconds)
S10
Delay time between loss of carrier and
hang up (1..255 in 10th of seconds)
