87
Appendix C - AT Command Summary
Apendix C - AT Command Summary
Command Values Description
AT
Attention Code that precedes most command strings
except A/, A: and Escape Codes.
RETURN
Pressing RETURN key executes most commands.
$
This symbol placed in dialing string enables the
modem to detect AT&T's "call card" tones for
accessing user's calling card to originate an on-line
connection.
A
Answer call, even if no ring present. Repeat last
command. (Do not precede this command with AT.
Do not hit RETURN to execute.)
A:
Continuous redial (10 redials in DOC units) of last
number until answered. (Not used Internationally.)
$A
n n = 0 or 1 * $A0 discards data during auto-reliable time period.
$A1 buffers data during auto-reliable time period.
#A
n n = 0 thru 3 * #A0 selects initial handshake at:33,600 to 31,200 to
28,800 to 24000 to 21,600 to 19,200 to 16,800 to
14,400 to 12,000 to 9600 to 4800 to 2400 to 1200 to
300 bps.
#A1 selects initial handshake at 33,600 bps only.
#A2 selects initial handshake at 33,600 to 31,200 to
28,800 to 24000 to 21600 to 19,200 to 16,800
19,200 to 14,400 to 9600 to 4800 bps.
#A3 selects initial handshake at 2400 to 1200 to 300
bps.
* Factory Default Setting
B
n n = 0 or 1 * B0 selects V.21 answer tone.
B1 selects Bell answer tone.
&B
n n = 0 or 1 * &B0 means normal transmit buffer size.
&B1 means reduced transmit buffer size.
&BS
n n = 0 or 1 &BS0 means maximum transmit block size of 64
characters.
* &BS1 means maximum transmit block size of 256
characters.
$BA
n n = 0 or 1 * $BA0 means speed conversion is on.
$BA1 means speed conversion is off.
&C
n n = 0,1,2,4 &C0 forces Carrier Detect on.
* &C1 lets Carrier Detect act normally.
&C2 lets Carrier Detect drop S24 time on
disconnect.
&C4 resets modem when Carrier Detect drops.
&CD
n n = 0 or 1 * &CD0 execute cleardown on disconnect.
&CD1 do not execute cleardown on disconnect.
D
s s = phone # Dial a telephone number “s,” where s may include
up to 60 digits or T, P, R, comma and ; characters.