Atdt – Multi-Tech Systems BL-Series User Manual

Page 52

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52

MultiModemBL User Guide

"Calling Card" Detect Tones $

The modem has the capability to detect AT&T "calling card" tones for the purpose of utilizing the
user's calling card number to originate an on-line connection. An $ symbol placed in the dialing string
causes the modem to pause and wait for an AT&T "calling card" or a 1600 Hz tone (prevalent in the
United Kingdom). When the tone is detected, the rest of the dialing string is processed. If no tones
are detected within the time period set by S-Register S7 (default 45 seconds), the modem will abort
by indicating a NO CARRIER message. Hitting any key also aborts the $ command.

The following is an example of this command:

ATDT

1028806127853500

$

123456789

(access/phone number) (credit card number)

Quiet Answer @

The @ command causes the modem to wait before processing the next symbol in the dialing string.
The wait is for one or more ringbacks followed by 5 seconds of silence. If the time specified by S-
Register S7 passes before the rings and silence, a NO ANSWER (R) result code is processed. The
@ command is used for accessing a system that does not provide a dial tone.

For example, ATDT5551212@6313550 causes the modem to dial the first number (555-1212) and
wait for the time specified in S7 for at least one ringback and 5 seconds of silence. If a busy signal is
detected, the modem hangs up and generates a BUSY result code. If it does not detect 5 seconds of
silence, a NO ANSWER result code is generated after hanging up. If 5 seconds of silence is
detected, the second number (631-3550) is then dialed.

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