Using Your Modem
3-6
Issue 2 May 1995
W – Wait for Dial Tone. The modem waits for a specified time
before expecting a second dial tone, then begins processing the
dial string. For example, if you must dial a 9 to reach an outside
telephone line, the W modifier delays the modem from dialing
until it receives a second dial tone for the outside line. The
amount of time the modem waits is determined by the setting of
S-Register S6. Once a dial tone is detected, or if the time period
runs out, the modem then processes the next command in the
dial string. If a busy signal is detected, the modem responds with
a busy response code and then goes into off-line command
mode.
R – Reverse Originate Mode. Places the modem in answer
mode. This modifier is used when calling an ‘originate-only’
modem. This modifier is the last character in the dialing string
(e.g., ATDT 123-4567R).
S=
n – Dial Stored Telephone Number. Causes the modem to
dial the telephone number which was previously stored in
memory by an &Z command.
@ – Wait for Quiet Answer. The modem will wait for a specified
amount of time (determined by S-Register S7), followed by five
seconds of silence before processing the next dial modifier. If
the silence is not detected, the modem sends a NO ANSWER
result to the computer.
! – Hook Flash. Causes the modem to go on-hook for
0.5 seconds. This modifier inserts a short on-hook time, typically
used for transferring a call.
; – Return to Command Mode. Modem returns to Command
mode after dialing a number without disconnecting the call. This
allows AT command strings that exceed the 60 character limit to
be linked together and is useful when using a calling card
number or an international telephone number.
