Chapter 2 - AT Commands, S-Registers, and Result Codes
MT3334SMI 21
Command: BnCommunication Standard Setting
Values: n = 0–3, 15, 16
Default: 1 and 16
Description: B0 Select ITU-T V.22 mode when modem is at 1200 bps.
B1 Select Bell 212A when modem is at 1200 bps.
B2 Deselect V.23 reverse channel (same as B3).
B3 Deselect V.23 reverse channel (same as B2).
B15 Select V.21 when the modem is at 300 bps.
B16 Select Bell 103J when the modem is at 300 bps.
Command: DsDial
Values: s = dial string (phone number and dial modifiers)
Default: none
Description: Dial telephone number s, where s may up to 40 characters long and include the 0–9, *, #, A, B, C,
and D characters, and the L, P, T, V, W, S, comma (,), semicolon (;), !, @, ^ and $ dial string
modifiers.
Dial string modifiers:
LRedial last number. (Must be placed immediately after ATD.)
PPulse-dial following numbers in command.
TTone-dial following numbers in command (default).
VSwitch to speakerphone mode and dial the following number. Use ATH command to hang up.
WWait for a new dial tone before continuing to dial. (X2, X4, X5, X6, or X7 must be selected.)
,Pause during dialing for time set in register S8.
;Return to command mode after dialing. (Place at end of dial string.)
!Hook flash. Causes the modem to go on-hook for one-half second, then off-hook again.
@Wait for quiet answer. Causes modem to wait for a ringback, then 5 seconds of silence, before
processing next part of command. If silence is not detected, the modem returns a NO ANSWER
code.
^Disable data calling tone transmission.
$Detect AT&T call card “bong” tone. The character should follow the phone number and precede
the user’s call card number: ATDT1028806127853500$123456789
Command: DS=yDial Stored Telephone Number
Values: n = 0–3
Default: none
Description: Dial a number previously stored in directory number y by the &Zy=x command.
Example: ATDS=3
Command: EnEcho Command Mode Characters
Values: n = 0 or 1
Default: 1
Description: E0 Do not echo keyboard input to the terminal.
E1 Do echo keyboard input to the terminal.
Command: FnEcho Online Data Characters
Values: n = 1
Default: 1
Description: F0 Enable online data character echo. (Not supported.)
F1 Disable online data character echo (included for backward compatibility with some software).
Command: HnHook Control
Values: n = 0 or 1
Default: 0
Description: H0 Go on-hook (hang up).
H1 Go off-hook (make the phone line busy).