User guide

74
Chapter 5 - AT Commands
to function in the telephone systems. Guard tones are not used in the United States. U.K.
models are locked at &G2 (1800 Hz guard tone).
&G0 disables ITU-T guard tones.
&G1 enables ITU-T 550 Hz guard tone.
&G2 enables ITU-T 1800 Hz guard tone.
Nn Modulation Handshake
n = 0 or 1
Default: N1
Controls whether the local modem performs a negotiated handshake with the remote modem at
connection time when the communication speed of the two modems is different.
N0 enables handshaking only at the communication standard specified by S37 and the ATB
command.
N1 always begins the handshake only at the communication standard specified by S37 and the
ATB command, but allows fallback to a lower speed as the handshake proceeds. This is the
default.
\Tn Inactivity Timer
n = 0
Default: \T0
The inactivity timer specifies the length of time, in minutes, that the modem waits before
disconnecting when no data is sent or received. This timer is specified in register S30. The \T0
command disables the inactivity timer.
Yn Long Space Disconnect
n = 0, 1
Default: Y0
When two modems are connected in reliable mode, a link disconnect request packet is sent to
request a disconnect. In non-error correction mode, there is no polite way to request a
disconnect. As a result, some garbage may be received when a hang-up command is issued.
Y0 disables the modem’s use of the break signal.
Y1 enables long space disconnect.