Rs485 Half-Duplex Interface - Datalogic DS6300 Reference Manual

CUSTOM CABLE ELECTRICAL CONNECTIONS

4.2.3 RS485 Half-Duplex Interface

This interface is provided for backward compatibility. We recommend using
the more efficient Lonworks network for Master/Slave or Multiplexer layouts.
NOTE
The RS485 half-duplex (3 wires + shield) interface can be used for polled communication
protocols.
It can be used for Multidrop connections with a Datalogic Multiplexer, (see par. "Multiplexer"
in Appendix A) exploiting a proprietary protocol based on polled mode called MUX32
protocol, where a master device polls slave devices to collect data. The overall maximum
cable length should not exceed 1200 m (3940 ft).
The following pins of the 25/26-pin connector are used for RS485 half-duplex interface
connection:
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
Genius™ utility or by the Host Programming Mode.
Figure 59 shows a multidrop configuration with DS6300 scanners connected to a Multiplexer.
This is an example of multidrop wiring. Consult the multiplexer manual for
complete wiring instructions.
CAUTION
Pin Name
2 RTX+
4 RTX-
7 GND_ISO
DS6300
2
4
7
1
Figure 58 – RS485 Half-Duplex Interface Connections
Function
RS485 input/output (+)
RS485 input/output (-)
Main signal ground
MULTIPLEXER
RTX+
RTX485+
RTX-
RTX485-
GND_ISO
RS485REF
CHASSIS
Earth
Ground
4
41