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DB9-dat

DB9	RS232	RS422	RS485
1	DCD	T- = A+	DATA- = A+
2	RX	T+ = B-	DATA+ = B-
3	TX	R+ = A+	-
4	DTR	R- = B-	-
5	GND	GND	GND
6	DSR	RTS-	-
7	RTS	RTS+	-
8	CTS	CTS+	-
9	RI	CTS-	-
10	-	-	-

sticker DB9 connector