Serial (RS232) modem cable (2-wire, DB25-DB25)
This cable should be used for DTE to DCE (for instance, from computer to a modem) connections without hardware handshaking.
 | DB25 pin D-SUB female to the PC |
 | DB25 pin D-SUB male to the modem |
| Female | Male | Direction | |
|---|---|---|---|
| Shield Ground | 1 | 1 | |
| Transmit Data | 2 | 2 | → |
| Receive Data | 3 | 3 | ← |
| System Ground | 7 | 7 | |
| Jumper these: | |||
| Request to Send | 4 | → | |
| Clear to Send | 5 | ← | |
| Data Set Ready | 6 | ← | |
| Carrier Detect | 8 | ← | |
| Data Terminal Ready | 20 | → | |
| Request to Send | 4 | → | |
| Clear to Send | 5 | ← | |
| Data Set Ready | 6 | ← | |
| Carrier Detect | 8 | ← | |
| Data Terminal Ready | 20 | → | |