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Software Usage and Examples
switching to pulse dialing will not correct. The program should ask the user what action to take if
condition
(2)
occurs. If the program finds either
BAD ANS
or
NO ANS
while it is pulse dialing, it should
ask the user what action to take, regardless of condition,
Dial Strings for Adaptive Dialing
Here is a more detailed explanation of the special characters that can be used in a dial string:
1)
The special character P means wait for dial tone, then dial the next digits adaptively. If no dial
tone is heard within
3-4.5
s, the
NO DIAL
response is reported. The first digit
(only
the first digit)
after the P will be dialed using tones. If no dial tone is heard, the remaining digits will be dialed
using tones. If a dial tone is heard, the en tire string after the P will be dialed using pulses.
Normally, the 0 command places an implied P at the beginning of the dial string. This causes any
dial string to be dialed adaptively. If P is the first character of a dial string, it will override the
implied P and force adaptive dialing. The modem will wait 3 s for a dial tone for the implied P,
and
4.5
s for a P in the dial string.
2) The special character W means wait 5 s, then dial the next digits using tones (until the next special
character is encountered). If W is the first character of a dial string, it will override the implied P
and force tone dialing,
3) The special character I means dial the next digits using pulses (until the next special character is
encountered). The
I
does not cause a wait. If
I
is the first character of a dial string, it will not
override the implied P-it will force pulse dialing after the implied P.
Examples of different dial strings are illustrated below.
TONE DIAL STRING. A dial string that dials a phone number using only tones starts with Wand has W
between the access codes:
W 9 W 1(800)555-1212
U
Lwait 5 s to attain
acces~
then force tone dialing
Dial access code
verride implied P, wait
5
s, then force tone dialing
With this dial string, the modem will not report the
NO DIAL
response. The implied P waits for a dial
tone and reports
NO
DIAL
if one is not heard, but the
W
overrides the implied P. The modem will
eventually report
NO ANS,
but it takes
50
s to report this condition. To allow
NO DIAL
to be reported
earlier (within
5
s), build the tone dial string starting with PW and placing W between the access codes:
37
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