📄 ppp-chat-abort.html
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> Many modems will report the status of the call as a
string. These strings may be CONNECTED or NO CARRIER or
BUSY. It is often desirable to terminate the script should the
modem fail to connect to the remote. The difficulty is that a
script would not know exactly which modem string it may
receive. On one attempt, it may receive BUSY while the next
time it may receive NO CARRIER.</P
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> These "abort" strings may be specified in the script using
the ABORT sequence. It is written in the script as in the
following example:</P
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> "ABORT" , "BUSY" ,
"ABORT" , "NO CARRIER" ,
"" , "ATZ" ,
"OK" , "ATDT5551212" ,
"CONNECT" , ... </PRE
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> This sequence will expect nothing; and then send the string
ATZ. The expected response to this is the string OK. When it
receives OK, it sends the string ATDT5551212 to dial the
telephone. The expected string is CONNECT. If the string
CONNECT is received the remainder of the script is
executed. However, should the modem find a busy telephone, it
will send the string BUSY. This will cause the string to match
the abort character sequence. The script will then fail because
it found a match to the abort string. If it received the string
NO CARRIER, it will abort for the same reason. Either string
may be received. Either string will terminate the chat script.</P
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