AT Commands F-17
AT Commands
\E
n Data Echo
\E0
Does not echo data sent by the local computer.
\E1
Echoes data sent by the local computer.
When operating in connect state, determines whether the modem echoes characters
sent from the local computer. \E1 functions only during normal mode connections.
%F
n V.23 Mode
%F0
Allows multi-protocol answering; disables V.23 mode on originating modem.
%F1
75 bps transmit, 1200 bps receive (split speed) V.23 operation.
%F2
1200 bps transmit, 75 bps receive (split speed) V.23 operation.
%F3
1200 bps transmit, 1200 bps receive (half duplex) V.23 operation.
Determines the V.23 mode used at 1200 bps. You can configure either channel with
the %Fn command for transmitting or receiving data. For split-speed operation, the
originating and answering modems must be set to opposite V.23 split-speed mode
command settings: set %F1 on the modem transmitting at 75 bps and %F2 on the
modem transmitting at 1200 bps. For example, if you set your modem to transmit data
at 1200 bps and receive data at 75 bps, it can establish a V.23 connection only with a
remote modem that transmits data at 75 bps and receives data at 1200 bps.
NOTE
Typing AT%Fn (where n=1, 2, or 3) disables all protocols except V.23. Typing
AT%Bn forces the %F0 setting.
During normal split-speed connections:
•
Set \J0 to operate at the speed of the serial port prior to the connection.
•
Set \J1 for a 1200 bps constant speed.
During direct connections, the computer must also be able to accommodate split
transmit and receive speeds. For other connections, you can use \Wn to control serial
port speed.
V.23 half-duplex operation is available only for direct and normal connections. V.23
half-duplex connections should have %F3 set on both modems.
