User Manual

Appendix A
Modem AT Commands
21
Xircom Inc. Mini PCI User’s Guide
P Pulse Dialing Method
The P modifier is used with the Dial command to instruct the modem to pulse dial the telephone
number that follows.
S=n Dial a Stored Telephone Number
The S modifier instructs the modem to dial a number that had been previously stored by the use
of the AT&Zn=x command. The command to dial a stored telephone number is ATDS=n, where
n represents telephone number storage location 0 or 1. For example, ATD P S=1 pulse dials the
telephone number written to telephone number storage location 1.
, Delay Processing the Next Character
When the comma (,) modifier is included as part of the dial string following the ATD command,
the modem pauses before processing the next character in the dial string. The duration of the
pause is dictated by the contents of S-Register S8.
The , modifier is frequently inserted after the digit (usually 9) used to obtain an outside line from
a PBX to allow sufficient time for the dial tone to occur before the modem dials the telephone
number. The W modifier can be used in place of the comma.
Some countries place restrictions on the amount of time a modem may delay during dialing.
T Tone Dialing Method
The T modifier is used with the Dial command to instruct the modem to tone dial the telephone
number that follows. See also the ATT command.
W Wait for Second Dial Tone
The W modifier instructs the modem to wait for a dial tone before processing the remaining
characters in the dial string.
! Hook Flash
The ! modifier serves as a switch hook (or hook flash) signal. This causes the modem to hang up
(go on-hook) for about 0.5 seconds then return to off-hook (the actual duration of the hook flash
varies in different countries).
@ Wait for Quiet Answer
The @ modifier in a dial string instructs the modem to wait for five seconds of silence after
dialing the number. If silence is not detected, the modem sends a NO ANSWER result code to
the user.
; Return to Command Mode after Dialing
The semicolon (;) dial modifier can be used only at the end of a command line, immediately
preceding the Enter, and instructs the modem to return to the command mode immediately after
dialing and without breaking the connection with the distant modem.