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6178-2203
&Qn – Asynchronous/Synchronous Mode
This command is an extension of the &M command and is used for controlling permitted connection
modes. It is used together with S36 and S48.
When the &Q0 to &Q4 command is issued, the subsequent connect message will report the line
speed regardless of the W command and S95 settings.
&Q0
Selects direct asynchronous mode. (See &M0)
&Q1
Selects synchronous communication mode and asynchronous command mode.
(See &M1)
&Q2
Selects synchronous communication mode and asynchronous command mode.
(See &M2)
&Q3
Selects synchronous communication mode with DTR as ”VOICE/DATA” switch.
(See &M3)
&Q4
Selects AutoSync mode. The value 100 is written to S27 bit 3, 1 and 0.
This mode enables synchronous communication from an asynchronous terminal.
Starting AutoSync.
Set registers S19, S20 and S25 to the right values before starting
AutoSync with &Q4. After the CONNECT message is issued, the modem waits for the
period of time specified by S25 before examining the DTR signal. If DTR is on the
modem enters the synchronous communication mode. If DTR is off the modem termi-
nates the line connection and returns to asynchronous command mode.
Stopping AutoSync.
If carrier is lost or if the DTR signal drops the modem will return
to the usual asynchronous mode. If &D1 is also set, the line connection will not be
terminated. (Other values for &D will cause this)
&Q5
The modem will try to negotiate an error-corrected link. The modem can be configured
using S36 to determine if the modem will go on-hook or decrease in speed. The value
101 is written to S27 bit 3, 1 and 0. (Default)
&Q6Selects normal asynchronous connection with speed buffering.
The value 110 is written to S7 bit 3, 1 and 0.
Please also refer to AT\N
%Q – Line Signal Quality
This command reports a numerical value for the line signal quality at V.22, V.22bis, V.32 and V.32bis.
This value should be as low as possible. Zero is best. The value varies however depending on the
type of modulation selected.
Please also refer to AT%L
&Rn – RTS/CTS Options
This command determines how the modem will handle CTS.
The CTS function changes if hardware handshake is set with &K3.
&R0
In synchronous mode the CTS signal follows the status of RTS. The delay between RTS
and CTS is set in register S26. In asynchronous mode the CTS function acts according to
V.25bis handshake.
&R1
In synchronous mode CTS is always on. In asynchronous mode CTS will only drop if
required by handshake. (Default)
