AT Commands
F-6 AT Commands
&C
nSerial Port DCD Control
&C0
DCD always On.
&C1
DCD follows the state of the carrier from the remote system; DCD turns On after the
connect message.
&C2
DCD On except momentarily at disconnect.
Controls the Carrier Detect (DCD) signal on the serial port. Use this command if your
computer requires DCD to be Off at certain times. See also the \D command
description.
NOTE
The &C and \D settings are ignored while connected in V.23 half-duplex direct
mode (%F3) or ITU-T V.13 (&R2). Hardware flow control overrides the &C and
\D settings for CTS operation. (See also \Q.)
@C
nCTS, DSR, and DCD Connect Message Control
@C0
CTS, DSR, and DCD On after the connect message is sent.
@C1
CTS, DSR, and DCD On before the connect message is sent.
Specifies whether CTS, DSR, and DCD go On before or after a connect message. Use
this command with :T14.
\C
nAuto-Reliable Buffer
\C0
Does not buffer data during link negotiation. Switches to normal or direct mode if no
SYN character detected within 3 seconds.
\C1
Buffers all data on the answering modem until it receives either 200 non-SYN
characters or a SYN character within 3 seconds (this delay is longer for modem speeds
300 or below). If it receives 200 non-SYN characters, the modem switches to normal
mode and passes the data through to the serial port. If it detects a SYN character within
3 seconds, it attempts to establish a reliable connection. Otherwise, it switches to
normal mode.
\C2
Does not buffer data on the answering modem. Switches to normal mode upon receipt
of a character defined by the AT%A command and passes that character to the serial
port.
