General DataComm SpectraComm V.34 Installation & Operation Manual page 84

AT Command Set Operation
Character length
\B n
&C n DCD operation
%C n Data compression
Fallback selection and
\C n
pre-link data buffer
4-4
Sets up the character length and format used by the modem in data mode for front
ends that do not send AT commands. The character length includes start, data,
parity, and stop bits.
\B0 6N1; Character length = 8 bits (6 data)
7N1; Character length = 9 bits (7 data)
\B1
7P1; DEFAULT Character length = 10 bits (7 data, 1 parity). With automatic parity
\B2
enabled (\P4), this also accommodates 8 data bits with no parity.
\B3 8N1; Character length = 10 bits (8 data)
7P2; Character length = 11 bits (7 data, parity, 2 stop)
\B4
Not supported by the V.42 and MNP protocols (\N2 through \N5).
\B5 8P1; Character length = 11 bits (8 data, parity).
Not supported by the V.42 and MNP protocols (\N2 through \N5).
Controls the EIA Data Carrier Detect signal.
Selects DCD to be forced On.
&C0
&C1 Selects DCD to be On after link established.
Selects DCD to be forced On; Toggle Carrier On disconnect.
&C2
Selects Real mode (follows modem energy detection.
&C3
Controls the selection of data compression for MNP-5 reliable, V.42 bis reliable, and
synchronous data links.
Disables data compression.
%C0
Enables data compression in both directions.
%C1
In V.42 bis or synchronous, enables data compression in the transmitter path.
%C2
In MNP 5, enables data compression in both directions.
In V.42 bis or synchronous, enables data compression in the receiver path.
%C3
In MNP 5, enables data compression in both directions.
Determines fallback selection. If an error correcting protocol is enabled, this
command determines whether incoming data from the remote modem will be
buffered while the receiver modem waits for establishment of the error correction link.
Receiver modem discards all incoming VF data from the remote modem until it has
\C0
PROTOCOL: NONE
sent a
data through.
\C1 Receiver modem buffers incoming VF data (up to 200 characters) until it has sent a
PROTOCOL: NONE
to the DTE. The modem will fall back to wire mode if more than 200 characters are
received before an error correction link is established.
Receiver modem discards all incoming VF data until it detects two consecutive
\C2
%A n
fallback characters (
passes one fallback character through to its DTE as data.
\C3 \C1
Same as , except that with no link the modem falls back to V.14 (direct) mode.
\C4 \C2
Same as , except that with no link the modem falls back to V.14 (direct) mode.
SpectraComm Dual V.34 Modem
Installation and Operation
AT Command Reference Tables
message to its DTE. Receiver modem then passes
message to its DTE. It then passes the buffered data through
), and then falls back to wire mode. The receiver modem
060R122-000
Issue 15