RS232 Null Modem Cable Pinout (DB9-DB9)
Use this cable between two DTE (Data Terminal Equipment) devices (for instance two computers).
![]() | DB9 pin D-SUB female to PC1 |
![]() | DB9 pin D-SUB female to PC2 |
| DB9-1 | DB9-2 | ||
|---|---|---|---|
| Receive Data | 2 | 3 | Transmit Data |
| Transmit Data | 3 | 2 | Receive Data |
| Data Terminal Ready | 4 | 6+1 | Data Set Ready + Carrier Detect |
| System Ground | 5 | 5 | System Ground |
| Data Set Ready + Carrier Detect | 6+1 | 4 | Data Terminal Ready |
| Request to Send | 7 | 8 | Clear to Send |
| Clear to Send | 8 | 7 | Request to Send |
Note: DSR & CD are jumpered to fool the programs to think that they are online.
Our software allows you monitor, log, debug and test your RS232 or COM ports.
Null modem (crossed) cable DB9-25 pin
Null modem (crossed) cable DB25-25 pin
Modem (straight) cable (DB9-DB25)
Modem (straight) cable (DB25-DB25)
Modem (straight) cable (DB9-DB15)
