Black Box MD1641A, MD1640A manual 122

SERIES II INTELLIGENT DATA/FAX MODEMS

6.Set DIP-Switch # 3 UP on both local and remote modems. This changes the transmit level to -15dB and this change is necessary to operate in back-to-back mode

7.Turn on both units and wait for carrier detect (CD).

8.Short out pins 2 and 3 on the RS-232C interface on the remote modem (with a paper clip or some other metal device, for example).

Remote sites:

Short Pins 2 and 3

of the RS-232

interface

PHONE	LINE	INTERFACE
		ON
	VOLUME	OFF
		POWER

PHONE	LINE	INTERFACE
		ON
	VOLUME	OFF
		POWER

PHONE	PSTN	LEASE	INTERFACE
			ON
		VOLUME	OFF
			POWER

PHONE	PSTN	LEASE	INTERFACE
			ON
		VOLUME	OFF
			POWER

Figure 8-4A. Back-to-Back Test Cabling

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