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 | DB-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.