User's Manual

Extended MNP- and V.42bis-Commands
AT\T Set Inactivity Timer
AT\X Set XON/XOFF Pass-Through
AT-J Set V.42 Detect Phase
AT%C MNP 5 Data Compression Control
AT%E Auto Retrain Control
AT%G Rate Renegotiations
AT"H V.42 bis Compression Control
AT"O V.42 bis String Length
AT - Attention Code
The AT (Attention) Code, which introduces each command line, can be
entered in upper-case or lower-case characters. Several commands
(separated by spaces if desired) can be positioned one after another, in one
line. A command line must end with the ASCII character which is stored in the
S3 or S4 Register (or with both together). The standard value for S3 is
Carriage Return (<CR>=13 decimal) and Line Feed (<LF>=10 decimal) for S4.
A command line without <CR>,<LF> will remain in the command buffer until
<CR>,<LF> is entered, or until the action is broken off with <Cntrl-X>. Once
<CR>,<LF> has been received, the modem carries out the commands
following the AT and answers with an appropriate modem message.
The maximum length of a command line is 40 characters. If the capacity of the
command buffer is exceeded, the modem issues an Error message.
=> The AT code enables the modem to recognize the speed, parity and
character length of the communication program
The ESC Sequence
If the modem has established a data connection, you can enter more
commands at any time, without breaking off the connection. This is achieved
by sending three ASCII characters (S2 Register) from the computer to the
modem. The standard setting is the “+” character. In order for this to be
interpreted as the ESC sequence, certain time limits must be observed in
entering the plus-characters. Before the first and after the last character, a
Guard time is required (the standard is 1 second) and the individual characters
must not be separated from each other by longer than this time period.
AT COMMANDS: DATA MODEM 2-3