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A.1.2
Bidirectional Data Ports
The schematic of bidirectional data port is shown in Figure A2. The schematics includes an
isolated full duplex RS-485 transceiver IC (Texas Instrument ISO3080) which is used as the main
component to handle both data input and output from external data source. The transceiver IC is
isolated from external input. To avoid signal reflection, the transceiver IC has an optional built-in
120Ω loop termination, which is selectable by the dip-switch on the junction box and the switch
should be set to on position when connecting external data source with long cable. All bidirectional
data ports are isolated from one another and are also isolated from internal power supply. The
transceiver internal power supply is fully isolated from the external power supply.
Figure A2 Schematic of bidirectional data port.
The output driver capability of bidirectional data port can provide a maximum of 60mA, and the
minimum differential output swing under 100 Ω load can be 2.3V.
A.1.3
A and B Signal Lines
Refer to sections A.1.1 and A.1.2.
A.1.4
Output Driver
The output driver capability of bi-direction data port can provide maximum 60mA, and the
minimum differential output swing under 100 ohm load can be 2.3V.
A.1.5
Input Load
Refer to sections A.1.1 and A.1.2.
A.1.6
Hardware Input/Output Circuit
Refer to sections A.1.1 and A.1.2.
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A.2
Presentation Interface of Smartfind M5
Figure A3 Presentation Interface of Smartfind M5