Advantech 2006957006 5th Edition user manual COM port connector CN20, Reference

C.18 COM port connector (CN20)

Table C-18: COM port connector (CN20)

Pin	Signal	Pin	Signal
1	DCD1	2	DSR1
3	RX1	4	RTS1
5	TX1	6	CTS1
7	DTR1	8	RI1
9	GND	10	NC
11	DCD2	12	DSR2
13	RX2	14	RTS2
15	TX2	16	CTS2
17	DTR2	18	RI2
19	GND	20	NC
21	DCD3	22	DSR3
23	RX3	24	RTS3
25	TX3	26	CTS3
27	DTR3	28	RI3
29	GND	30	NC
31	DCD4	32	DSR4
33	RX4	34	RTS4
35	TX4	36	CTS4
37	DTR4	38	RI4
39	GND	40	NC

Note:	The cable of serial port (CN20) comes
	with four DSUB-9 male connectors. The
	pin assignments of each DSUB-9
	connector are listed below for your
	reference:

4

2

3

1

100 PCM-9570/S User's Manual