57
Command
Function/Options
&J
n
Telephone jack control.
*&J0
No function. Included for compatibility.
&J1
No function. Included for compatibility.
&K
n
DTE/Modem flow control.
&K0
Disable flow control.
*&K3
Enable RTS/CTS.
&K4
Enable X-ON/X-OFF.
&K5
Enable transparent X-ON/X-OFF.
&K6
Enable both RTS/CTS and X-ON/X-OFF.
&P
n
Select pulse dial make/break ratio.
*&P0
USA/Canada ratio (39/61 at 10 pps).
&P1
UK/Hong Kong ratio (33/67 at 10 pps).
&P2
Same as &P0, except at 20 pps.
&P3
Same as &P1, except at 20 pps.
&Q
n
Asynchronous mode.
&Q0
Direct asynchronous mode. All error correction
and compression protocols are disabled. This
requires that the software’s baud rate matches
modem baud rate.
*&Q5
Modem negotiates an error correction link.
&Q6
Selects asynchronous operation in normal
mode. (Speed buffering allows software baud
rate to be fixed.)
&R
n
RTS/CTS option.
&R0
In sync mode, CTS tracks the state of the RTS
signal; the RTS-to-CTS delay is defined by
register S26. In async mode, the CTS signal
acts according to V.25bis handshake.
*&R1
In sync mode, CTS is always ON (RTS transition
is ignored). In async mode, CTS will only drop if
required by flow control.
&S
n
Data Set Ready (DSR) signal.
*&S0
DSR override; always ON.
&S1
DSR signal ON after answer tone is detected,
and OFF after the carrier is lost.
CHAPTER 9: Modem Command Set (AT Commands)