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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