Specifications
AN93
Rev. 0.8 29
Table 20. Basic AT Command Set
Command Action
$
Display Basic AT command mode settings (see text for details).
A
Answer incoming call.
A/
Re-execute last command (executes immediately—not preceded by “AT” or followed by <CR>).
Dn
Dial
The dial command, which may be followed by one or more dial command modifiers, dials a phone
number:
Modifier Function
! or & Flash hook-switch for U4F (FHT) ms (default: 500 ms)
, or < Pause before continuing for S8 seconds (default: 2 seconds)
; Return to AT command mode after verifying dialtone and dialing any
digits.
G Telephone voting mode. This modifier, intended for use in Japan,
enables a special dial-in voting mode that may be used with certain
automated voting systems. When this modifier is placed anywhere in
the dial string (e.g, ATDG), the Si2493/57/34/15/04 dials the phone
number and waits S7 seconds (60 by default) to detect a busy tone.
When the busy tone is detected, the Si2493/57/34/15/04 reports
whether a polarity reversal occurs between the time the last digit is
dialed and the detection of the busy tone. If the S7 timeout occurs
prior to a busy tone detect, “NO CARRIER” will be reported. Polarity
reversal monitoring begins after the last digit is dialed and ends when
a busy tone is detected or S7 times out.
The Si2493/57/34/15/04 reports either “POLARITY REVERSAL” or
“NO POLARITY REVERSAL”. It is not possible to establish a modem
connection when using this command.
L Radial Last Number
P Pulse (rotary) dialing—pulse digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
T Tone (DTMF) dialing—DTMF digits: *, #, A, B, C, D, 0, 1, 2, 3, 4, 5, 6,
7, 8, 9
W Wait for dial tone before continuing for S14 seconds (default:
12 seconds). Blind dialing modes X0, X1, and X3 do not affect the W
command.
If the DOP bit (U7A, bit 7) is set, the “ATDTW” command causes the
Si2457/34/15 to pause dialing and either report an “OK” if a dialtone is
detected or “NO DIALTONE” if a dial tone is not detected.
En
Local DTE echo.
E0
Disable.
E1
Enable.
Hn
Hook-switch.
H0
Go on-hook (hang up modem).
H1
Go off-hook.
In
Identification and checksum.