Set DIP switches example

Set these DIP switches according to your serial device requirements (EIA-232/422/485).

Up/On   Down/Off
DB-9 pin	EIA-232	EIA-422/485 Full-duplex	EIA-485 Half-duplex
1	DCD	CTS-	Not used
2	RxD	RxD+	RxD+
3	TxD	TxD+	TxD+
4	DTR	RTS-	Not used
5	GND	GND	GND
6	DSR	RxD-	RxD-
7	RTS	RTS+	Not used
8	CTS	CTS+	Not used
9	RI	TxD-	TxD-
Shell	GND