CBX ELECTRICAL CONNECTIONS
47
4
4.2.2 RS485 Full-Duplex Interface The RS485 full-duplex (5 wires + shield) interface is used for non-polled communication
protocols in point-to-point connections over longer distances (max 1200 m / 3940 ft) than
those acceptable for RS232 communications or in electrically noisy environments.
The CBX pinout follows:
CBX100/500 Function
TX+ RS485 Transmit Data +
RX+ RS485 Receive Data +
TX- RS485 Transmit Data -
RX- RS485 Receive Data -
SGND Signal Ground
RX485+ TX485+
SGND RX485- TX485-
USER INTERFACE
SGND TX+ RX+
TX- RX-
READER
Figure 52 - RS485 Full-duplex Connections
NOTE
For applications that do not use RX485 signals, do not leave these lines
floating but connect them to SGND as shown below.
RX485+
SGND RX485-
USER INTERFACE
SGND TX+
TX-
READER
Figure 53 - RS485 Full-duplex Connections using Only TX Signals