Multi-Tech Systems MT5600DSVD User Manual
Page 36
MultiModemDSVD User Guide
4 AT Commands, S-Registers, and Result Codes
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Command:
&M
n Communications Mode
Values:
n = 0
Default:
0
Description:
This command determines the DTR operating mode. The mo-
dem treats the &M command as a subset of the &Q command.
&M0 Selects direct asynchronous operation. Note that the command
sequence &M0\N0 selects normal buffered mode, but the
command sequence \N0&M0 selects direct mode. This is be-
cause the \N0 command is analogous to the &Q6 command.
Command:
&P
n
Pulse Dial Make/Break Ratio
Values:
n = 0
Default:
0
Description:
&P0
Selects a make/break dial ratio of 39:61 at 10 pulses per sec-
ond.
Command:
&Q
n Asynchronous Communications Mode
Values:
n = 0, 5, 6
Default:
5
Description:
This command is an extension of the &M command, 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.
&Q5 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 disconnecting or falling back
to a non-error-correction connection. See also \N3.
&Q6 Selects asynchronous operation with speed buffering and no
error correction. Same as \N0.
Command:
&S
n
Data Set Ready (DSR) Control
Values:
n = 0 or 1
Default:
0
Description:
&S0
Force DSR high (on) at all times.
&S1
Let DSR go high only during a connection.
Command:
&T
n
V.54 Test Commands
Values:
n = 0, 1, 3, 4, 5, 6, 7, or 8
Default:
None
Description:
The modem can perform selected test and diagnostic functions.
A test can be run only when the modem is in asynchronous
operation in non-error-correction mode (normal or direct mode).
For tests 3, 6, and 7, a connection between the two modems
must first be established. To terminate a test in progress, the
escape sequence (+++) must be entered first, except for param-
eters 7 and 8. If S18 is non-zero, a test terminates automatically
after the time specified by S18 and displays the OK message.
&T0
Abort. Stop any test in progress.
&T1
Start local analog loopback, V.54 Loop 3. If a connection exists
when this command is issued, the modem hangs up. The CON-
NECT XXXX message is displayed upon the start of the test.