The DB25 (originally DE-25) connector is an analog 25-pin plug of the D-Subminiature connector family (D-Sub or Sub-D). The DB25 connector is mainly used for serial connections, allowing for asynchronous data transmission as provided by standard RS-232 (RS-232C). It is also used for parallel port connections and was used to connect printers, that's why it's also known as a printer port (LPT). DB25 serial ports on computers have male connectors, while parallel port connectors are DB25 female.
How do male and female connectors look like?
What are pins for serial connection?
| Pin number |
Name |
|
| 2 |
TXD - Transmit Data |
|
| 3 |
RXD - Receive Data |
|
| 4 |
RTS - Request To Send |
|
| 5 |
CTS - Clear To Send |
|
| 6 |
DSR - Data Set Ready |
|
| 7 |
GND - Signal Ground |
|
| 8 |
CD - Carrier Detect |
|
| 20 |
DTR - Data Terminal Ready |
|
| 22 |
RI - Ring Indicator |
|
What are pins for parallel connection?
| Pin number |
Name |
|
| 1 |
_STR - Strobe |
|
| 2 |
D0 - Data bit 0 |
|
| 3 |
D1 - Data bit 1 |
|
| 4 |
D2 - Data bit 2 |
|
| 5 |
D3 - Data bit 3 |
|
| 6 |
D4 - Data bit 4 |
|
| 7 |
D5 - Data bit 5 |
|
| 8 |
D6 - Data bit 6 |
|
| 9 |
D7 - Data bit 7 |
|
| 10 |
ACK - Acknowledgement |
|
| 11 |
Busy |
|
| 12 |
Paper Out |
|
| 13 |
Select |
|
| 14 |
Auto feed |
|
| 15 |
Error |
|
| 16 |
Reset |
|
| 17 |
Select Input |
|
| 18 |
Ground |
|
| 19 |
Ground |
|
| 20 |
Ground |
|
| 21 |
Ground |
|
| 22 |
Ground |
|
| 23 |
Ground |
|
| 24 |
Ground |
|
| 25 |
Ground |
|
