Appendix A AT Commands
31
parentheses are ignored by the modem and may be included in the dial string
to enhance readability.
Dial Modifiers
Modifier
Function Name
Description
L
Dial the last number Instructs the modem to dial the last
number dialed. This modifier is valid
only if it is the first symbol of the dial
string. All consecutive characters are
discarded.
P
Select pulse dialing —
T
Select tone
dialing(default)
—
W
Wait for dial tone
Instructs the modem to wait for a
second dial tone before processing the
dial string.
,
Dial pause
Instructs the modem to pause before
processing the next character in the dial
string. Register S8 determines the
length of the pause.
!
Hook flash
Instructs the modem to go on-hook for
0.5 s and then return to off-hook.
@
Wait for quiet
answer
Instructs the modem to wait for 5 s of
silence after dialing the number. If
silence is not detected, the modem
sends a NO ANSWER result code back
to the user.
;
Return to command
mode
Instructs the modem to return to
command mode after it has finished
dialing without disconnecting the call.
This modifier must be the last character
in the dial string.
$
Bong tone detection —
S=<location> Dial from register
Instructs the modem to dial a telephone
number previously stored using the
&Z<location>=<dial string>
command. Valid storage locations are
0—3.
