Telenetics 56 Manuel D’Utilisation
Page 110
AT&C Controlling Data Carrier Detect
The &C command enables you to control how DCD will operate. DCD is a RS-232 interface
signal from the modem to a remote device, such as a terminal or a computer, indicating that the
modem is receiving a carrier signal from a remote modem. This signal is switched on (asserted)
when your modem is receiving a valid carrier signal from a remote modem. The &C3 option
allows a connection that was commenced as a voice call to switch to fax or data mode without an
interruption to the DCD signal (which might cause the application to think that the line has been
lost).
signal from the modem to a remote device, such as a terminal or a computer, indicating that the
modem is receiving a carrier signal from a remote modem. This signal is switched on (asserted)
when your modem is receiving a valid carrier signal from a remote modem. The &C3 option
allows a connection that was commenced as a voice call to switch to fax or data mode without an
interruption to the DCD signal (which might cause the application to think that the line has been
lost).
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The &C command will only have effect when the DCD option switch is in the UP
position and %T0 is selected. (Refer to the Dumb Mode Section for details.)
Options
AT&C0
DCD signal is always asserted
AT&C1
■
DCD signal responds to remote modem
AT&C2
DCD signal always on, pulses low on disconnect
AT&C3
DCD asserted during voice session
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We recommend &C2 for UNIX computers which require DCD to be asserted when
issuing commands to the modem.
issuing commands to the modem.
Range
0-3
See Also
S Register 9
Carrier Detect Response Time
S Register 10
Lost Carrier/Hang Up Delay
%T
DCD Control
Dumb Mode Switches
%P
Connect Message Timing