Rs485 half-duplex interface, 3 rs485 half-duplex interface – Datalogic Scanning Compact 2D Reader Matrix-2000 User Manual

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MATRIX-2000™ REFERENCE MANUAL

5

5.5.3 RS485

Half-Duplex

Interface


The opto-isolated 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 70 and par.
6.4) 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_ISO

Main opto-isolated reference ground



MATRIX

RTX-

RTX+

MULITPLEXER

RTX485-

RTX485+

GND_ISO

RS485REF

SHIELD

4

2

7

1

Earth Ground

Earth Ground

Chassis

Figure 69 - 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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