User's Manual

Connecting the RS485 Four-Wire Communication Line
Reader RD21 Installation and Connections 2-3
Connecting the RS485 Four-Wire Communication Line
The four-wire RS485 data-communication line must be used for connecting the Readers to the
main system PC. For detailed information regarding the four-wire RS485 interface (full-duplex),
see the RFID System S21 Technical Guide. The RS485 connectors and jumper are located on the
Motherboard MBD21. The MBD21 is the bottom board of the Reader Module Assembly.
Notes 1. For RS485 line, use a specially designed cable only
, such as, BELDEN type 9842, or similar.
An alternate approved list of cable can be obtained from Lyngso industri A/S. 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 MBD21. Connect the incoming RS485 cable to one connector and
the out going RS485 cable to the other.
Figure 2-2: Connections and Jumper Settings for the RS485 Four-Wire Communication Line
To connect the RS485 communication lines to the Reader, refer to Figure 2-2 and:
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 Reader’s enclosure.
3. Connect the four-wire communication line to the corresponding pins A, B, Z and Y on terminal
block TB4 (or TB6). Connect the cable shield to the pin indicated by the ground symbol on
terminal block TB4 (or TB6).
Interface
Selection
J3
RS485
RS232
RESET
CNO CO M C NC
A B Z Y
A B Z Y
+ - OS I/0
+ 8V DTA PWR
J1
Load
Open
J2
Load
Open
DATA
POWER
A B Z Y
A B Z Y
TB4
Incoming Cable
Outgoing Cable
TB6
P3
1
P1
J1
Load
Open
P2
J1
Load
Open
Controller CTL21
J2
S95
S21
J3
J1
Load
Open
Load
Open