User's Manual

Connecting the Exciter Communication Line
2-4 Reader RD21 Installation and Connections
Caution Before installing the RFID System, label the 4 wires on the RS485 line as A, B, Z and Y. Keep this
naming convention for all connections made on this RS485 communication line.
4. Set the termination load for the RS485 communication line. The ends of a multidrop network
line can be easily identified, because only one RS485 cable is connected to that equipment. To
connect a 120 ohm terminating load, place the jumper P1 between pins 1-2 of J1(load
position). For any other equipment connected to this RS485 communication line, place the
jumper P1 between pins 2-3 of J1 (Open position).
5. To select the RS485 interface, place the jumper P2 between pins 2-3 of J2.
6. Plug terminal blocks TB4 and TB6 into connectors TB3 and TB5 respectively.
Connecting the Exciter Communication Line
Two separate RS485 two-wire interfaces are used to communicate between Readers and Exciters.
For more information regarding the communication link, see the RFID System S21 Technical
Guide. The RS485 connectors and jumpers for these lines are located on the Controller Board
CTL21. The CTL21 is the top board of the Reader Module Assembly.
Notes 1. For the RS485 line, use specially designed cables only, such as, BELDEN type 9842, or
similar.
2. To simplify the RS485 multidrop-type connection, the two RS485 connectors, TB4 and TB6,
are wired in parallel on the MBD21. Connect the incoming RS485 cable to one connector and
the out going RS485 cable to the other.
To connect Exciter communication lines to the Reader, refer to Figure 2-3 and:
Complete the following steps:
1. Unplug terminal blocks TB2 and TB4 from connectors TB1 and TB3 respectively.
2. Run the RS485 incoming and out going cables through the cable grips into the Reader’s
enclosure.
3. Connect the four-wire communication line to the corresponding pins A1, B1, A2, and B2 on
terminal block TB2 (or TB4). Connect the cable shield to the pin marked G on terminal block
TB2 (or TB4).
Figure 2-3: Connections and Jumper Settings for the Exciter Communication Line