IBM 2193 Personal Computer User Manual


 
Modem information
B-5
Modem commands
This section provides information on the modem commands if you operate your
modem from the DOS prompt using the AT command strings.
Executing commands
Your modem is in the Command Mode when powered-on and is ready to receive
and execute AT commands. The modem remains in the Command Mode until it
makes a connection with a remote modem. Commands may be sent to the modem
from an attached terminal or a computer running a communication program.
The modem is designed to operate at common DTE speeds ranging from 300 bps
to 115.2K bps. All commands and data must be issued to the modem using one of
the valid DTE speeds.
Command format
All commands must begin with the
AT
prefix, followed by the command letter and
ended with the
Enter
key. Spaces are allowed in the command string to increase
command readability but are ignored by the modem during command execution. All
commands may be typed in either upper or lower case, but not mixed. A command
issued without any parameters is considered as specifying the same command with
a parameter “0”.
Example:
ATL
[
Enter
]
This command causes your modem to lower its speaker volume.