Black Box MD1641A, MD1640A manual Reliable Mode &E2, Mode Select #L, Originate Mode, Answer Mode

SERIES II INTELLIGENT DATA/FAX MODEMS

Reliable Mode &E2

In Reliable mode, the Series II Modem uses its V.42 error correction capabilities during all transmissions, and must be connected to another modem with a similar protocol activated (MNP or LAP-M).

V.42 Mode Select #L

The V.42 standard implements both MNP Class 3 & 4 and LAP-M error correction methods. The V.42 Mode Select command (#L) selects which type of error correction (MNP or LAP-M) your Series II Modem uses for transmissions.

The various #L command options are as follows.

#L0 Command	The #L0 Command allows a pair of
	modems to negotiate which V.42 mode
	(MNP or LAP-M)will be used in their
	transmissions.
	Originate Mode
	a. If both modems have LAP-M capability,
	the modems use LAP-M mode.
	b. If one or both modems do not have LAP-
	M capability and both have MNP, the
	modems use the MNP mode.
#L0 Command (cont'd)	Answer Mode
	a. The answering modem responds to either
	an MNP Link Request or LAP-M Originator
	Detection Pattern (ODP) signal depending
	on which the originating modem issues.
#L1 Command	The #L1 Command sets your modem to
	MNP error correction and disables LAP-M.
	This command is for Originate mode only.
	In Answer mode, the modem still accepts
	MNP or LAP-M.
#L2 Command	The #L2 Command sets your modem to
	LAP-M error correction, and disables MNP.

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