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RS-422/485 Pin Assignment
The pin assignment scheme for a 4-pin RS-422 is given below.
RS-422 : PIN 1 : T+ PIN 2 : T- PIN 3 : R+ PIN 4 : R-
RS-485 : PIN 1 : D+ PIN2 : D-
RS-422 Wiring Diagram
Serial Device This Bluetooth adapter
T+ 3 R+
T- 4 R-
R+ 1 T+
R- 2 T-
RS-485 Wiring Diagram
Serial Device This Bluetooth adapter
D+ 1 D+
D- 2 D-
1 2 3 4