PCI Express Boards Pin Assignments
2-wire RS-485
Pin Signal Pin Signal Pin Signal
1 Data3+(B) 16 – 31 –
2 – 17 Data3-(A) 32 –
3 – 18 – 33 GND3
4 – 19 – 34 –
5 Data2+(B) 20 – 35 –
7 – 22 – 37 GND2
8 – 23 – 38 –
9 Data1+(B) 24 – 39 –
10 – 25 Data1-(A) 40 –
11 – 26 – 41 GND1
13 Data0+(B) 28 – 43 –
14 – 29 Data0-(A) 44 GND0
15 – 30 –
Device Side Pin Assignments
Male DB9 (CBL-M44M9x4-50)
Pin RS-232 RS-422/RS-485-4W RS-485-2W
2 RxD TxD+(B) –
3 TxD RxD+(B) Data+(B)
4 DTR RxD-(A) Data-(A)
5 GND GND GND
6 DSR – –
8 CTS – –
9 – – –
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) –
4 RTS – –
5 CTS – –
6 DSR – –
7 GND GND GND
20 DTR RxD-(A) Data-(A)
22 – – –