19-PIN CONNECTOR ELECTRICAL CONNECTIONS
5
5.5.2 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 following pins of the 25-pin connector are used for RS485 full-duplex communication:
Pin Name Function
2 TX+ RS485 Transmit Data (+)
4 TX- RS485 Transmit Data (-)
3 RX+ RS485 Receive Data (+)
5 RX- RS485 Receive Data (-)
7 GND_ISO Main opto-isolated reference ground
MATRI
GND_ISO
RX+
RX-
TX-
TX+
USER INTERFACE
TX485
RX485
SHIELD
Reference Ground
7
3
5
4
2
+
1
-
+
-
Earth Ground Earth Ground
Chassis
Figure 67 - RS485 Full-duplex Connections
NOTE
For applications that do not use RX485 signals, do not leave these lines
floating but connect them to GND_ISO as shown below.
MATRI
GND_ISO
RX+
RX-
TX-
TX+
USER INTERFACE
RX485
SHIELD
Reference Ground
7
3
5
4
2
+
1
-
Earth Ground Earth Ground
Chassis
Figure 68 - RS485 Full-duplex Connections using Only TX Signals
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