Filter
Top Products
Appendix F - Modem AT Commands
RF300E/RF310E 173
&D1 causes the modem, if in online data mode, to enter command mode, issue an OK and remain
connected when the DTR drops.
&D2 causes the modem to hang up when DTR drops while the modem is in online data mode.
&D3 causes the modem to reset when DTR drops . It will also hang up if it is online.
&Sn Data Set Ready Control
n = 0 or 1
Default: &S0
Controls the state of the Data Set Ready (DSR) signal on the RS-232/V.24 interface. Normally, DSR
follows CD. You can force the signal high or allow it to act normally.
&S0 forces DSR high (on).
&S1 allows DSR to act normally, that is, to follow CD.
Error Correction and Data Compression Commands
You can configure modems to any of three different V.42 modes of operation (with or without
compression): non-error correction, auto-reliable, and reliable modes. You also can turn data
compression on or off.
\Nn Error Correction Modes
n = 0, 1, 2, 3, 4, 5, or 7
Default: \N3
Select the modem’s error correction mode using the \N command.
\N0 disables the modem’s V.42 error correction capabilities, and the modem functions as a non-error
correction modem with data buffering. This is the same as &Q6, described earlier in this chapter.
\N1 causes the modem to function in direct mode.
\N2 enables reliable mode, in which the modem uses its V.42 error correction capabilities for all
transmissions. In reliable mode, the modem must be connected to a modem with the V.42 MNP
protocol.
\N3 enables auto-reliable mode. During the handshaking procedures at the start of the online
connection, the modem queries whether the other modem is using V.42 error correction. If the
modem determines that the other modem is using V.42, it switches itself into reliable (V.42) mode and
enables error correction. If it determines that the other modem is not using V.42, the modem remains
in non-error correction mode. (This is the same as \N5 and \N7.)
\N4 enables reliable mode, in which the modem uses its V.42 error correction capabilities for all
transmissions. In reliable mode, the modem must be connected to a modem with a V.42 protocol
(MNP or LAP-M).
The V.42 standard includes MNP Class 3 and 4 and LAP-M error correction methods.
\N5 enables auto-reliable mode. During the handshaking procedures at the start of the online
connection, the modem queries whether the other modem is using V.42 error correction. If the
modem determines that the other modem is using V.42, it switches itself into reliable (V.42) mode and
enables error correction. If it determines that the other modem is not using V.42, the modem remains
in non-error correction mode. (This is the same as \N3 and \N7).
\N7 enables auto-reliable mode. During the handshaking procedures at the start of the online
connection, the modem queries whether the other modem is using V.42 error correction. If the
modem determines that the other modem is using V.42, it switches itself into reliable (V.42) mode and
enables error correction. If it determines that the other modem is not using V.42, the modem remains
in non-error correction mode. (This is the same as \N3 and \N5).