Chapter 5 – AT Commands, S-Registers, and Result Codes
SocketModem Global MT5634SMI Developer’s Guide 29
Command: &Sn Data Set Ready (DSR) Control
Values: n = 0 or 1
Default: 0
Description: &S0 DSR is always high (on).
&S1 DSR goes high only during a connection.
Command: &Tn Loopback Test (V.54 Test) Commands
Values: n = 0, 1, 3, 6
Default: None
Description: The modem can perform selected test and diagnostic functions. A test can be run only when
the modem is operating in non-error-correction mode (normal or direct mode). For tests 3
and 6, a connection between the two modems must be established. To terminate a test in
progress, the escape sequence (+++AT) must be entered.
&T0 Stops any test in progress.
&T1 Starts a local analog loopback, V.54 Loop 3, test. If a connection exists when this
command is issued, the modem hangs up. When the test starts, a CONNECT
message is displayed.
&T3 Starts local digital loopback, V.54 Loop 2, test. If no connection exists, ERROR is
returned.
&T6 Initiates a remote digital loopback, V.54 Loop 2, test without self-test. If no connection
exists, ERROR is returned.
Command: &V Display Current Settings
Values: n/a
Description: Displays the active modem settings.
Command: &Wn Store Current Configuration
Values: n = 0 or 1
Default: 1
Description: &W0 Stores current modem settings in non-volatile memory and causes them to be loaded
at power-on
or following the ATZ command instead of the factory defaults. See also the &F
command.
&W1 Clears user default settings from non-volatile memory and causes the factory defaults
to be loaded at power-on or following the ATZ command.
Command: &Zy=x Store Dialing Command
Values: y = 0–2
x = Dialing command
Default: None
Description: Stores dialing command x in memory location y. Dial the stored number using the command
ATDS=y. See Also the #CBS command, a callback security command.
Command: \An Select Maximum MNP Block Size
Values: n = 0, 1, 2, or 3
Default: 3
Description: \A0 64-character maximum.
\A1 128-character maximum.
\A2 192-character maximum.
\A3 256-character maximum.
Command: \Bn Transmit Break
Values: n = 0–9 in 100 ms units
Default: 3
Description: In non-error-correction mode only, sends a break signal of the specified length to a remote
modem. Works in conjunction with the \K command.