INSTALLATION
2
DS4600A
USER INTERFACE
7
SGND Main
TX485+
2
TX485-
4
RX485+
3
RX485-
5
RX485
TX485
RS485REF
Earth
Ground
Figure 10 - RS485 Full-Duplex Connections
RS485 Half-Duplex Interface
The RS485 half-duplex (3 wires + shield) interface is used for polled communication
protocols.
It can be used for Multidrop connections in a master/slave layout or with a Datalogic
Multiplexer, (see par. 2.6.4 and 2.6.5).
The following pins of the 25-pin connector are used for RS485 half-duplex
communications:
Pin Name
Function
2
RS485 transmitted/received data +
4
RTX485-
RS485 transmitted/received data -
7
SGND Main
signal ground main interface
DS4600A
MULTIPLEXER
2
RTX485-
4
RTX485-
7
SGND Main
RS485REF
Figure 11 - RS485 Half-Duplex Connections
11