Quatech SSU2-400I operation manual RS-422 Pin Assignment

Serial Device		USB to RS-232/422/485 Converter
2	RX	3	TX
3	TX	2	RX
5	GND	5	GND
7	RTS	8		(Flow Control)
			CTS
8	CTS	7		(Flow Control)
			RTS

□RS-422 Pin Assignment

The pin assignment scheme for a 4-pin RS-422 is given below.

1 2 3 4

RS-422:	PIN 1: T+	PIN 2: T- PIN 3: R+ PIN 4: R-
RS-485:	PIN 1: D+	PIN 2: D-

□RS-422 Wiring Diagram

Serial Device		USB to RS-232/422/485 Converter
R-		2	T-
	R+	1	T+
	T-	4	R-
	T+	3	R+

□RS-485 Wiring Diagram

Serial Device		USB to RS-232/422/485 Converter
	D-	2	D-
	D+	1	D+

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