Specifications
76 MultiModemISI Hybrid Series, ISIHI-2S/2U
Chapter 4—MODEM AT Commands, S-Registers, Result Codes
F Dummy command
&Gn Guard Tones
n = 0, 1, or 2
Default: &G0 (models outside U.K.) or &G2 (U.K. models only)
Controls the presence or absence of guard tones from the transmitter when in answer
mode at either 1200 or 2400 bps. Guard tones are used in Europe and other areas to allow
the modem 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 modems use of the break signal.
Y1 enables long space disconnect.