Black Box MD1650A-JP, Reference Manual

Page: 13 / 56

CHAPTER 2: AT Commands
11
Description (continued): &M3 Selects synchronous connect mode. This mode allows DTR to
act as a talk/data switch. A call is manually initiated while DTR
is inactive; when it becomes active, the handshake proceeds in
originate or answer mode according to S14 bit 7.
Command: &P n Make/Break Dial Ratio
Values: n = 0, 1, 2, or 3
Default: Varies by country/region
Description: &P0 Make/Break dial ratio of 39/61 at 10 pps
&P1 Make/Break dial ratio of 33/67 at 10 pps
&P2 Make/Break dial ratio of 39/61 at 20 pps
&P3 Make/Break dial ratio of 33/67 at 20 pps
Command: &Q n Sync/Async Mode
Values: n = 0–3, 5, 6
Default: 5
Description: This command is an extension of &M and is used to control which
connection modes are permitted. It is used in conjunction with S36
and S48. (See also the \N command.)
&Q0
Selects direct asynchronous operation. See &M0.
&Q1 Selects synchronous connect mode with asynchronous offline
command mode. See &M1. Serial interface operation only.
&Q2 Selects synchronous connect mode with asynchronous offline
command mode; enables DTR dialing of directory 0. See &M2.
Serial only.
&Q3 Selects synchronous connect mode with asynchronous offline
command mode; enables DTR to act as a talk/data switch. See
&M3. Serial only.
&Q5 The modem will try to negotiate an error-corrected link. It can
be configured using non-error-correction connection. See also
\N3.
&Q6 Selects asynchronous operation with speed buffering and no
error correction. Same as \N0.
Command: &R n Clear to Send (CTS) Control
Values: n = 0 or 1
Default: &R0 Lets the CTS state follow the RTS state when online.
&R1 Forces CTS high (ON).
NOTE
This command applies only in synchronous mode.
Command: &S n Data Set Ready (DSR) Control
Values: n = 0 or 1
Default: 0
Description: &S0 Forces DSR high (on) at all times.
&S1 Lets DSR go high only during a connection.