15
AT COMMANDS
Bold text indicates Async Dial factory defaults.
AT
Attention Command Prefix/Autobaud
Rate. Indicates a command string has
started and determines the DTE’s data
rate and parity.
A/
Repeat Last Command. Reexecutes last
command string. (Not to be preceded
with AT or followed by pressing the
Return key.)
A
Answer Mode. Goes off-hook and
attempts to establish a connection
without waiting for a ring.
B0
ITU-T V.21 or V.22 (300 or 1200 bps)
B1
Bell 103 or 212A (300 or 1200 bps)
Dn
Dial. Dials the telephone number n with
optional modifiers:
T
Tone Dial (DTMF)
P Pulse
Dial
,
Pause
W
Wait for Dial Tone
R
Reverse Dial
@
Quiet Answer
!
Hook Flash
;
Return to Command Mode
DS=n
Dial Stored Number. Dials the number
stored in location n (1–10).
En
Command Character Echo
E0
Disables echo to the DTE.
E1
Enables echo to the DTE.
H0
Modem goes on-hook.
H1
Modem goes off-hook.
I
0
Displays product code–144.
I
1
Displays 3-digit firmware revision
number.
I
2
Performs an EPROM check.
I
3
Displays modem’s serial number.
I
4
Displays modem’s model number.
I
5
Displays part number of circuit card.
I
6
Displays firmware release number.
I
9
(same as
I
1)
I
10=n
Changes value of product code (0=144,
1=240, 2=480, 3=960, 4=120).
I
11
Firmware checksum.
I
19
Displays entire firmware revision number.
Ln
Speaker Volume
L0,L1
Selects low volume.
L2
Selects medium volume.
L3
Selects high volume.
AT COMMANDS (continued)
Mn
Speaker ON/Off Control
M0
Speaker always Off.
M1
Speaker ON until carrier signal
becomes active.
M2
Speaker always ON.
O
Returns modem to Data mode from
online Command mode.
P
Enables Pulse Dial mode.
Qn
Result Codes
Q0
Enables result codes. Refer to Result
Codes section.
Q1
Disables result codes.
Q2
Enables originate modem to send result
codes to the DTE. Required for most
UNIX applications.
Sn?
Displays value of S-Register (where n is
the register number).
Sn=r
Change S-Register. Changes the
contents of the S-Register (where n is the
register number and r is the assigned
value).
T
Enables Tone Dial mode.
Vn
Result Code Format
V0
Displays as digits (Numbers 1).
V1
Displays as text.
V2
Displays as digits (Numbers 2).
Xn
Extended Result Codes; Dial Tone
Detect; Busy Tone Detect
X0
Disables extended result codes 5–16,
dial tone detect, and busy tone.
X1
Enables extended result codes 5–16,
disables dial tone detect and busy tone
detect. Refer to Result Codes section.
X2
Enables extended result codes 5–16, dial
tone detect, and disables busy tone
detect.
X3
Enables extended result codes 5–16,
disables dial tone detect and enables
busy tone detect. Refer to Result Codes
section.
X4
Enables extended result codes 5–16,
dial tone detect, and busy tone detect.
Refer to Result Codes section.
X5
Adds EC suffix to extended result codes
(20–27) if error control is used, enables
dial tone detect and busy tone detect.
X6
Adds either V.42 or MNP suffix to
extended result codes (20–27) if data
compression is used, enables dial tone
detect, and busy tone detect.
X7
DTE rate appears in CONNECT
message instead of line rate, enables dial
tone detect and busy tone detect. Refer
to Result Codes section.