Allied Data Technologies TRON SECURE 33.6, Руководство пользователя

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3 MODEM COMMANDS
In this chapter, the commands of the TRON SECURE 33.6 are discussed. Most modems and
communication software make use of the AT command set. Modem manufacturers have added
their own comman-ds to the AT command set. Through this, we cannot speak of a standard
anymore. A distinction is made between the Standard AT”and the Extended AT”command set.
A number of reasons can be given for the differences between modem commands. By different
inspection requirements, certain commands or settings are not allowed in some countries. There
are also differences between American and European transmission standards (Bell versus
CCITT).
The TRON SECURE 33.6 accepts both the Standard and the Extended AT command set. Apart from
that, a number of specific commands were added.
Moreover, for the use of a fax the modem knows the AT+F commands. These commands are not
discussed in the manual, since they work together with specific software only.
In the first paragraph of this chapter it is explained when the modem is in the command mode.
After that, the structure of a command line is discussed. Then, an enumeration of the AT
commands follows, after which each command is clarified. A separate chapter is devoted to the
S registers.
3.1 Command mode and data mode
The modem knows two modes:
1. Command mode
In this mode, the modem executes commands that are typed in through the terminal.
The modem is in the command mode when it is not on-line or, in case of a data
connection, when it was switched to the command mode through the escape
sequence.
2. Data mode
The modem is transparent, which means that information being exchanged through
both modems remains unchanged. With a data connection, the modem is in the data
mode most of the time. If the modem has to execute a command, this can only be done
from the command mode. During a connection, the modem can be switched to the
command mode through the escape sequence.
Escape sequence: wait 1 second
type: +++
after 1 second: OK
The modem is now in the command mode.
With ATO, the modem returns to the data mode.
TRON SECURE 33.6
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