User's Manual
V34bis Fax-modem - AJ 2885 P
AJ 2885 P - Page 28
CONFIGURATION PARAMETER (38,400 BPS)
CONNECTION RESULT
Autobaud
Async / Sync
Mode
DCE sped
DCE speed
DTE speed
@A1 : ON
&M1 : Sync
Do not care
Do not care
33600
33600 (1)
@A2 : DTE
@A0 : OFF
&M1 : Sync
Do not care
@M15: 28800
28800
28800 (1)
@A1 : ON
&M0 : Async
*M1 : normal
*M2 : auto
*M3 :
exclusive
Do not care
33600
38400 (2)
@A1 : ON
&M0 : Async
*M0 : direct
Do not care
33600
33600 (3)
@A2 : DTE
@A0 : OFF
&M0 : Async
*M1 : normal
*M2 : auto
*M3 :
exclusive
@M4 : 9600
9600
38400 (4)
@A2 : DTE
@A0 : OFF
&M0 : Async
*M0 : direct
@M4 : 9600
9600
9600 (5)
Remark :
(1) The synchronous mode parameter &M1 is dominating : DTE speed depends on the
connection speed. It may also vary during connection in case of retrain or fall back
negotiated with the remote modem for example.
(2) Except for direct mode (*M0), Autobauding (@A1) is dominating : DCE speed
depends on the terminal DTE speed. The default factory configuration is based on
this configuration.
(3) Direct mode parameter (*M0) is dominating : DTE speed change to the DCE speed
upon connection. Any speed change should be avoided in asynchronous mode since
the DTE terminal could not adapt to any further speed change.
(4) Autobauding is either limited to the DTE speed detection (@A2) or disabled (@A0) :
DCE connection speed can be set up independently thanks to the @M parameter.
DTE terminal speed remains unchanged in asynchronous mode (constant DTE
speed).
(5) Again Autobauding is either limited to the DTE speed detection (@A2) or disabled
(@A0) : the @M parameter sets the DCE connection speed independently from the
DTE speed. But, DTE terminal speed becomes the DCE speed upon connection
because of direct mode (*M0). Again, any speed change should be avoided in
asynchronous mode since the DTE terminal could not adapt to any further speed
change.
5.3.
Rate and connection mode selection
The AJ 2885 provides several solutions to determine the mode of connection.
Selecting connection mode for speeds of 2400 to 19200 BPS : the modem can connect
these speeds in V34 mode or in older V22, V22Bis, V32Bis or V32 is modes. The AT
@OM command selects the wanted mode of connection This command should be left as
@OM3 for automatic mode adaptation since the V34 mode is designed to recognise V32 /
V32Bis remote modems during the handshake.
Autobaud
: the modem recognises automatically the speed and the data format of the
terminal when it sends an AT command. If the 'full' autobaud is active - AT @A1 - then the
modem will adapt the connection rate to the nearest lower connection speed. This is the
