Comtrol AT Commands - Manual (Page 53)

AT Commands for CX81801/CX06833/CX81300/CX06827 Modems Reference Manual
102184B Conexant 3-27
&Q - Sync/Async Mode
This command is an extension of the &M command and is used to control the connection
modes permitted. It is used in conjunction with S36 and S48. (Also, see \N.)
NOTE: When the &Q0 to &Q3 command is issued to select the mode, the subsequent
connect message will report the DCE speed regardless of the W command and S95
settings.
Syntax
&Q<value>
Defined Values
<value> Decimal number corresponding to the selected option.
0 Selects direct asynchronous operation. The value
000b is written to S27 bits 3, 1, and 0,
respectively. See &M0.
1 Selects synchronous connect mode with async
off-line command mode. The value 001b is
written to S27 bits 3, 1, and 0, respectively. See
&M1. (Serial interface operation only.)
2 Selects synchronous connect mode with async
off-line command mode and enables DTR
dialing of directory 0. The value 010b is written
to S27 bits 3, 1, and 0, respectively. See &M2.
(Serial interface operation only.)
3 Selects synchronous connect mode with async
off-line command mode and enables DTR to act
as Talk/Data switch. The value 011b is written to
S27 bits 3, 1, and 0, respectively. See &M3.
(Serial interface operation only.)
5 The modem will try to negotiate an error-
corrected link. The modem can be configured
using S36 to determine whether a failure will
result in the modem returning on-hook or will
result in fallback to an asynchronous connection.
The value 101b is written to S27 bits 3, 1, and 0,
respectively. (Default.)
6 Selects asynchronous operation in normal mode
(speed buffering). The value 110b is written to
S27 bits 3, 1, and 0, respectively.
Result Codes
OK <value> = 0 to 3, 5, or 6
ERROR Otherwise.