3 AT Commands
CommPlete Communications Server 25
%DCnAT Command Control
n
= 0 or 1
Default: %DC0
The %DC command allows you to disable the modem’s ability to respond to AT commands. It can be used
with auto answer applications in which no call origination is required, with some UNIX applications, and
with other applications that require you to disable the modem’s command mode.
%DC0 enables command mode.
%DC1 disables command mode.
Note: If you save %DC1 as part of your default configuration, you can re-enable command mode by typing
AT%DC0 and pressing ENTER in the first ten seconds after you power up the modem.
&CDnCleardown at Disconnect
n
= 0 or 1
Default: &CD0
In the V.32, V.32bis, and V.34 protocols, a cleardown is sent by one of the modems to si gnal the other
modem that it is going to hang up. A cleardown is rate renegotiation in which the modem that is hanging
up tells the other modem that it has no speeds that it can connect at. It is designed to help the remote
modem detect a hang-up. However, it does take a second or two to send the cleardown. If you find this
delay unacceptable, you can disable cleardown by using the &CD command.
&CD0 enables cleardown at disconnect.
&CD1 disables cleardown at disconnect.
>DTnDTMF Detection
n
= 0 or 1
Default: >DT0
Normally, when it goes off-hook, a fax modem ignores tones from the other end of the connection unless
they are fax or modem handshake tones, in which case it responds in kind. The >DT1 command causes
the modem to report DTMF (touch-tone) tones and fax calling tones to software for further processing. A
typical use would be for a program that routes calls to specific communications applications depending on
the type of call or upon a DTMF tone added to a dialing string.
>DT0 disables DTMF detection.
>DT1 enables DTMF detection when the modem goes off-hook.