750 CHAPTER 52: CONFIGURING MODEM
Syntax description of modem script
The modem script format in common use is as follow:
receive-string1 send-string1 receive-string2 send-string2......
Where:
■Normally, receive-string and send-string appear in pairs, and the script must
begin with a receive-string. For example, “receive-string1 send-string1”
represents the execution flow: Expect to receive receive-string1, and send
send-string1 to the modem if the received string matches receive-string1
before timing out. Otherwise, the execution of the subsequent script will be
terminated.
■If the last string is a send-string, it indicates that the execution of the script will
be terminated after the string is sent without waiting for any receive-string.
■If it is unnecessary to receive a string at the beginning of a script, and the
system can directly wait for the send-string, then the user can set the first
receive string to "", which will be explained later.
■Except for ending with “\c”, the send-string will be automatically added with
an additional return character to its end when it is sent.
■A receive-string is matched via the location-independent matching method.
That is, the match is considered successful as long as the received contents
contain the expected string.
■The match operation on a receive-string will be considered successful if the
receive-string is matched with any expected receive-strings which are separated
with “-“.
■The default timeout time waiting for a receive-string is 5 seconds. TIMEOUT
seconds can be inserted into the script anytime to adjust the timeout time
waiting for the receive-string, which is valid till a new TIMEOUT is set in the
same script.
■All the strings and keywords in a script are case sensitive.
■Both the strings and keywords are separated by spaces. If a space is contained
in a string, it should be put in the double quotation marks (" "). A pair of
empty quotation marks (that is, "") have two meanings. Being a leading "" in
a script, it means that no string is expected from the modem and the system
will directly send the strings to the modem. If "" locates in any other locations,
the string content will be regarded to be "".
■ABORT receive-string can be inserted at any point in a script to change the
script execution flow. Its presence in the script indicates that the script
execution will be terminated if a received string is fully matched the
receive-string set by ABORT receive-string. Multiple ABORT entries can be
defined in a script, and they will take effect concurrently. Once a received string
matches any of them, the script execution will be terminated. Regardless of
where the ABORT receive-string is placed, it will take effect in the whole script
execution process.
■Escape characters can be inserted in a script for the purpose of better
controlling the script and increasing its flexibility. In addition, all the escape
characters are the delimiters in the string at the same time.