Multi Tech Equipment ISIHI-2S manual Gn Guard Tones, Nn Modulation Handshake, Tn Inactivity Timer

Chapter 4—MODEM AT Commands, S-Registers, Result Codes

&Gn Guard Tones

n = 0, 1, or 2

Default: &G0 (models outside U.K.) or &G2 (U.K. models only)

The &G command 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

This command 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 S3. The \T0 command disables the inactivity timer.

Yn Long Space Disconnect

n = 0 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.

Modem

MultiModemISI Hybrid Series, ISIHI-2S 75