INSTALLATION 2
RS485 Full-Duplex Interface
The RS485 full-duplex interface is used for non-polled communication protocols in
point-to-point connections over longer distances than those acceptable for RS232
communications or in electrically noisy environments. The overall maximum cable length
should not exceed 1200 m (3937 ft).
The following pins of the 26-pin connector are used for RS485 full-duplex interface connection:
Pin Name Function
2 TX485 + RS485 output (+)
3 RX485 + RS485 input (+)
4 TX485 - RS485 output (-)
5 RX485 - RS485 input (-)
7 GND-ISO Main signal ground
DS8100A
7GND_ISO
TX485+
2
RX485+
3
TX485-
4
RX485-
5
TX485+
TX485-
SGND Main Isolated
USER INTERFACE
RX485-
RX485+
1
Earth
Ground
CHASSIS
Figure 11 - RS485 Full-Duplex Interface Connections
RS485 Half-Duplex Interface
The RS485 half-duplex interface can be used for multidrop connections with a Datalogic
multiplexer or it can also be used for a master/slave layout. The overall maximum cable
length should not exceed 1200 m (3937 ft).
The following pins of the 26-pin connector are used for RS485 half-duplex interface
connection:
Pin Name Function
2 RTX485 + RS485 input/output (+)
4 RTX485 - RS485 input/output (-)
7 GND-ISO Main signal ground
DS8100A
7 GND_ISO
RTX485+
2
RTX485-
4
RS485REF
MULTIPLEXER
RTX485-
RTX485+
1
Earth
Ground
CHASSIS
Figure 12 – RS485 Half-Duplex Interface Connections
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