AT&T System 85 manual 286

8434 and 8434DX Voice Terminal

Wiring Information

The 8434 and 8434DX voice terminals work in both 4-wire and 2-wire DCP configurations. The table below describes the pins on an 8400-Series voice terminal LINE jack.

		LINE INTERFACE
PIN	PAIR	NAME	DESCRIPTION
1	2	OD1	4-Wire Output
2	2	OD2	4-Wire Output
3	3	ID1	4-Wire Input
4	1	U-T	2-Wire (Tip)
5	1	U-R	2-Wire (Ring)
6	3	ID2	4-Wire Input
7	4	P1-	Adjunct Power -48V
8	4	P2+	Adjunct Power Common

Notes: Regardless of which configuration is in use, ALL wiring between the PBX and the terminal MUST consist of twisted-pairs, including the modular line cord. The line cord must be a D8W, which consists of 4 twisted-pairs, or an AT&T approved equivalent.

Twisted-pair wiring is used to make lines less sensitive to crosstalk. Therefore, failure to use twisted pair wiring may result in less-than-optimum performance of the terminal and may also contribute to problems with the line.

An 8-wire modular cord MUST be used for all 4-wire and any 2-wire installations requiring auxiliary power.

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