D-Link DirectPort DMF-560TXD, Руководство пользователя

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3. MODEM BASICS
This chapter covers the basic commands and
techniques involved in modem operation. In many
cases, this is the only information you will need in
order to get your DirectPort PC Card up and running
with communication software, and to start making
connections with your PC Card.
3.1 Understanding AT Commands
The DirectPort PC Card communicates
asynchronously with computers using AT commands.
AT commands are used to configure and control the
PC Card. Commands are usually sent to the modem in
way of communication software, but can also be
entered manually with the computer keyboard.
Command statements must be written in a specific
form in order for the DirectPort PC Card to
recognize them. A command statement always begins
with the letters
AT or at . It is then followed by one or
more commands and the <Enter> key.
AT commands can only be issued when the
DirectPort PC Card is in ”Command mode” or ”off-
line.” Once the PC Card has established a connection
with another modem, it is said to be ”on-line” or in
”Data mode.” In this mode, the characters sent to the
E 56K Fax/Modem PC Card by your
computer are transmitted to the remote modem rather
than being interpreted by the PC Card as commands.
Using the Windows 95/98 Hyper Terminal Program
To issue an AT command statement, you first need to
run a communication program such as the Microsoft