RS-232
Ref: Wikipedia
RS-232 / COM port / Serial port
Connector
- DB-25
- DE-9 (AKA DB-9)
- Usually use DE-9
- DTE (male)
- DCE (female)
DE-9
DE-9 is correct name, but usually name DB-9
Ref: D-subminiature
Pin
| Pin | SIG | Name | DTE (male) |
|---|---|---|---|
| 1 | DCD | Data Carrier Detect | in |
| 2 | RXD | Receive Data | in |
| 3 | TXD | Transmit Data | out |
| 4 | DTR | Data Terminal Ready | out |
| 5 | GND | Signal Ground | - |
| 6 | DSR | Data Set Ready | in |
| 7 | RTS | Request To Send | out |
| 8 | CTS | Clear To Send | in |
| 9 | RI | Ring Indicator | in |
Common usage
RXD TXD GND