Instruction manual
25-PIN CABLE ELECTRICAL CONNECTIONS 
5
5.3.3 RS485 Half-Duplex Interface 
NOTE 
This interface is provided for backward compatibility. We recommend using 
the more efficient ID-NET™ network for Master/Slave or Multiplexer layouts. 
The RS485 half-duplex (3 wires + shield) interface is available for polled communication 
protocols. 
It can be used for Multidrop connections with a Datalogic Multiplexer, (see par. 
6.5) exploiting 
a proprietary protocol based on polled mode called MUX32 protocol, where a master device 
polls slave devices to collect data. 
The following pins of the 25-pin connector are used for RS485 half-duplex communication: 
Pin Name  Function 
2  RTX+  RS485 Receive/Transmit Data (+) 
4  RTX-  RS485 Receive/Transmit Data (-) 
7 GND  Ground 
RTX+
2
RT
X
-
4
RTX485 + 
RTX485 -
7
GND 
MULTIPLEXER 
RS485REF
Matrix 200™
1
Chassis
Figure 66 - RS485 Half-duplex Connections 
This interface is forced by software when the protocol selected is MUX32 protocol. 
In a Multiplexer layout, the Multidrop address must also be set via serial channel by the 
VisiSet™ utility or by the Host Programming Mode. 
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