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4.3
Labelling
The module has a “COMM PORT” with the connector pins, labelled from left to right as:
“ + GND – ”
+ = RS485 “A” circuit connection
GND = Common
– = RS485 “B” circuit connection
4.4
Connectors
A three-position screw cable connector is used for Modbus communication.
4.5
Wiring and connections
The Modbus
wiring should be connected to module connector “+”, “GND”, “–“.
Figure 5: Modbus "Comm Port"
NOTE:
RS485 is polarity sensitive. "+" wires must connect to other "+" terminals and "
–
" wires must
connect to
other "
–
" terminals. The shield wire is connected to the centre terminal.
