CBX800 INSTALLATION MANUAL
17
Host 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 CBX800 pinout follows:
Pinout
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-
CBX800
Figure 17 - 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-
CBX800
Figure 18 - RS485 Full-duplex Connections using Only TX Signals