V.22 bis Modem with AT Commands
CMX866
©
2008 CML Microsystems Plc
23
D/866/5
The CMX866 returns a CONNECT xxxx result code when a connection is
established, where xxxx is the Tx/Rx line speed, otherwise it returns a NO
CARRIER result code (default).
Z Factory
Reload
Reloads the factory default S-Register settings (See S-Register Table).
Syntax:
ATZ<CR>
1.5.4.4 Extended AT Commands
Command Description
&Cn Carrier
Detect
Determines the action of the DCDN pin.
Syntax:
AT&Cn<CR>
Modifier Usage
n=0
DCD is always on (DCDN pin is held permanently low).
n=1
DCD follows the received carrier. If a carrier is present on the line, then DCD
is on (DCDN pin is held low). Otherwise DCD is off (DCDN pin is held high)
(default).
&Dn
Data Terminal Ready
Determines the meaning of the DTRN pin.
Syntax:
AT&Dn<CR>
Modifier Usage
n=0
DTRN pin is ignored
n=1
When an on to off transition of DTR occurs (DTRN pin goes from low to high),
the CMX866 goes into Command mode (if it was in Data Transfer mode), after a
fixed delay of 100ms, during which time the transition is qualified. Whilst in
Command mode, if DTRN remains high for more than 500ms, then the CMX866
goes on-hook.
n=2
Same as above (n=1), except that the CMX866 also goes on-hook when the
DTRN transition is qualified.
&Gn
Guard Tone Select
Selects the Guard tone to be transmitted with highband QAM or DPSK.
Syntax:
AT&Gn<CR>
Modifier Usage
n=0
Disable guard tone (default).
n=1
Enable 550Hz guard tone.
n=2
Enable 1800Hz guard tone.