Schneider Electric PWRSRV710 CONNECTING 4-WIRE DEVICES AS 2-WIRE, Biasing and Termination

Chapter 4—Connections	63230-216-207/A3
Connecting 4-Wire Devices as 2-Wire	9/2002
Biasing and Termination	Each RS-485 port has built-in communications signal biasing and
	termination circuitry. Thus, a multipoint communications adapter is not
	needed. However, an end-of-line terminator (Square D part no. MCT-485 or
	MCTAS-485) is required on the last device of each daisy chain. Refer to the
	instruction bulletin for the last device on the daisy chain.

CONNECTING 4-WIRE DEVICES AS 2-WIRE

Two DB9-to-terminal block adapters (female) [Square D part no. DB9F2TB] are included with the Power Server. Use an adapter to connect a 4-wire device as 2-wire to the Power Server. Refer to Figure 4–7 and follow these steps:

1.On the DB9F2TB adapter, jumper the Rx+ and Tx+ terminals together, and jumper the Rx– and Tx– terminals together.

2.Connect the Rx+/Tx+ terminals to the L+ line.

3.Connect the Rx–/Tx– terminals to the L– line.

4.Plug the DB9F2TB adapter into the RS-485 port on the Power Server.

DB9F2TB to

Power Server

Typical 2-wire

POWERLOGIC device

L –

L + Shield

1

4

6

9

Tx –

Rx +

Shield

Tx +

Rx –

30703011

Figure 4–7: Typical 2-wire POWERLOGIC device connection to Power Server

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