User's Manual

LF Antenna Connections
Exciter EX21 Installation and Connections 3-3
LF Antenna Connections
The LF antenna is a 7-turn loop coil with the tap at the first turn. To create this multiturn loop and
the proper tap connection, complete the following steps:
1. Position the antenna cable inside the plastic box as shown in EX21 Assembly. Cut the end
closest to the terminal block - 110mm long, and the other - 360mm long.
2. Remove 80mm of the outside cable jacket, and strip about 8mm from each conductor isolation.
3. Use a crimping tool to connect cable conductors in the butt splices as shown in Figure 3-1.
Figure 3-1: LF Antenna Connections
Connecting the RS485 Communication Lines
The RS485 connectors and jumpers are located on the LFA21 assembly placed inside the plastic
enclosure (see the assembly drawing 900061). Two separate RS485 two-wire lines are used to
transmit data from/to the Reader. For detailed information on the RS485 two-wires interface (half-
duplex), see the RFID System S21 Technical Guide.
Notes 1. For the RS485 line, use specially designed cables only, such as BELDEN type 9842, or similar.
For more information, see the RFID System S21 Technical Guide.
2. To simplify the RS485 multidrop-type connection, the two RS485 connectors, TB4 and TB6
are wired in parallel on the LFA21 board. Connect the RS485 incoming cable to one connector
and the RS485 out going cable to the other.
From Exciter
LFA21
Assembly
7 Conductors
Antenna Cable
Ends
Butt Splices
1
2
3
4
5
6
7
8
Black
Red
Brown
Green
Orange
Blue
White
Black
Red
Brown
Green
Orange
Blue
White
7 Conductors
Antenna Cable
Ends
White
Red
Black
Ant Tap Gnd