PCI Express Boards Pin Assignments
RS-485-2W
Pin Signal Pin Signal Pin Signal
1 DATA4+ 16 – 31 –
2 – 17 DATA4- 32 –
3 – 18 – 33 –
4 – 19 – 34 –
5 DATA3+ 20 – 35 –
7 – 22 – 37 –
8 – 23 – 38 –
9 DATA2+ 24 – 39 –
10 – 25 DATA2- 40 –
11 – 26 – 41 –
13 DATA1+ 28 – 43 –
14 – 29 DATA1- 44 –
15 – 30 –
Device Side Pin Assignments—Male DB9
PIN RS-232 RS-422/RS-485-4W RS-485-2W
1 DCD TxD-(A) –
2 RxD TxD+(B) –
3 TxD RxD+(B) Data+(B)
4 DTR RxD-(A) Data-(A)
5 GND GND GND
7 RTS – –
8 CTS – –
Male DB25 (CBL-M44M25x4-50)
PIN RS-232 RS-422/RS-485-4W RS-485-2W
2 TxD RxD+(B) Data+(B)
3 RxD TxD+(B) –
5 CTS – –
6 DSR – –
7 GND GND GND
8 DCD TxD-(A) –
20 DTR RxD-(A) Data-(A)