INSTALLATION

2

 

2.3.2RS485 Half-Duplex Main Interface

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 Figure 13 and par. 2.6.2).

The following pins of the 25-pin connector are used for RS485 half-duplex communication:

Pin

Name

Function

2

RTX485+

Transmitted/received data (+)

4

RTX485-

Transmitted/received data (-)

7

SGND*

Main reference ground

*SGND is internally connected to the GND through a filtering circuit.

MATRIXMULITPLEXER

2

RTX485+ RTX485+

4

RTX485- RTX485-

7

SGND RS485REF

SHIELD

1

Earth

 

Ground

 

 

 

Figure 13 - RS485 Half-duplex Connections

 

15