AT Commands
102906_01_en
PHOENIX CONTACT
6-1
6
AT Commands
Your modem stores its operating characteristics in a non-volatile memory (EEPROM). You
can overwrite these characteristics using commands and can thus modify the method of
operation of the device. The modem executes commands as long as it is in command
mode. Your modem is automatically in command mode until you dial a number and
establish a connection. You can enter commands for your modem using appropriate
communication software (e.g., HyperTerminal). The device supports data transmission
speeds of 300, 1200, 2400, 4800, 9600, 19,200, 38,400, 57,600, and 115,200 bps.
Modes
The modem can be operated in two modes:
–
Command mode:
The modem can be configured and controlled via AT commands.
As soon as a connection is established, the modem automatically switches to data
mode.
–
Data mode:
In this mode, the modem transmits data to the partner.
Command Structure
All commands transmitted to the modem must start with
AT
and must be confirmed by
pressing ENTER. The commands can be entered in either upper or lowercase, but not a
mixture of the two. Spaces may be inserted between the commands so that the command
lines are easier to read.
Correct a Typing Error
If you make a mistake when entering a command, you can correct it using the backspace
key. Pressing the backspace key deletes the last character entered. The
AT
at the start of
the command line is not deleted.
Repeat the Previous Command
You can instruct your modem to repeat the previous command by entering
A/
in command
mode.
AT
is not entered for this command and it does not have to be confirmed by pressing
ENTER, i.e., the command is repeated as soon as
A/
is entered.
Make sure that the baud rate setting for your COM port in your communication software
corresponds to one of these speeds.
AT
deletes the last command line executed by your modem (if present) and prepares
your modem for the new command line. In addition,
AT
informs your modem of the
transmission speed, parity, and character length.
For commands that must be specified by a parameter, a missing parameter corresponds
to parameter 0, e.g.,
ATM
=
ATM0
.
