RS-232 (DB9)

1 Carrier Detect (8)
2 Receive Data (3)
3 Transmit Data (2)
4 Data Term Ready (20)
5 Signal Ground (7)
6 Data Set Ready (6)
7 Request To Send (4)
8 Clear To Send (5)
9 Ring Indicator (22)

* El numero del parentesis es el equivalente a un conector de 25 pins (DB25)