Specifications

AN93
30 Rev. 0.9
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 dial
tone and dialing any digits.
@ Wait for silence. Returns “No Answer” when call is
terminated without a silent period after ringing.
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 sec-
onds (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 dial-
ing and either report an “OK” if a dial tone is
detected or “NO DIALTONE” if a dial tone is not
detected.
En
Local DTE echo.
E0
Disable.
E1
Enable.
Table 18. Basic AT Command Set (Continued)
Command Action