Table of RS232 Pin Designations | |
1 | Ground |
2 | Transmitted data (TD) |
3 | Received data (RD) |
4 | Request to send (RTS) |
5 | Clear to send (CTS) |
6 | Data set ready (DSR) |
7 | Ground |
8 | Data carrier detect (DCD) |
9 | Not connected |
10 | Not connected |
11 | Not connected |
12 | Secondary data carrier detect |
13 | Secondary clear to send |
14 | Secondary transmitted data |
15 | Secondary transmitted clock |
16 | Secondary received data |
17 | Receiver clock (RC) |
18 | Divided clock receiver (DCR) |
19 | Secondary request to send |
20 | Data terminal ready (DTR) |
21 | Signal quality detect (SQ) |
22 | Ring indicator (RI) |
23 | Data rate selector |
24 | External transmitter clock |
25 | Busy |