User's Manual

Connecting the RS485 Communication Lines

3-4 Exciter EX21 Installation and Connections

To connect RS485 communication lines to the LFA21, refer to Figure 3-2 below.

Figure 3-2: Connections and Jumpers Settings for the RS485 Communication Lines

complete the following steps:

1. Unplug terminal blocks TB4 and TB6 from connectors TB3 and TB5 respectively.

2. Run the RS485 incoming and out going cables through the cable grips into the plastic

enclosure.

3. Connect the RS485_CMD line to pins A1, B1, and RS485_SGN line to the pins A2, B2 on

terminal block TB4 (or TB6). Connect the cable shield to the pin marked G on terminal block

TB4 (or TB6).

Caution Before installing the RFID System, label the 2 wires on the RS485_CMD line A1 and B1; label the

2 wires on the RS485_SGN line A2 and B2. Keep this naming / wire colour convention for all

connections made on these RS-485 communication lines.

4. Set the terminating load for the each RS485 communication line. The ends of a multidrop-

network line could be easily identified, because only one cable is connected to the

equipment.To connect a 100 ohm terminating load to the RS485_CMD line, place the jumper

P2 between pins 1-2 of J4. When connecting any other equipment to this RS485

communication line, place the jumper P2 between pins 2-3 of J4.

To connect a 100 ohm terminating load to the RS485_SGN line, place the jumper P3 between

pins 1-2 of J5 (Load position). When connecting any other equipment to this RS-485

communication line, place the jumper P3 between pins 2-3 of J5 (Open position).

5. Plug terminal blocks TB4 and TB6 into connectors TB3 and TB5 respectively.

Test

S21

S95

1 2 3 4

A B Z Y

TB4

Incoming Cable

Out going Cable

TB6

RS485_ CMD RS485_ SGN RS485_ CMD RS485_ SGN

Load

Open

Load

Open