Signal db 9 pin db 25 pin
signal ground           GND 5 7
transmitted data       TxD 3 2
received data           RxD 2 3
data terminal ready   DTR 4 20
data set ready           DSR 6 6
request to send        RTS 7 4
clear to send           CTS 8 5
carrier detect          DCD 1 8
ring indicator           RI 9 22