Null Modem Cable Pinout (DB9-DB25)
Use this cable between two DTE devices (for instance two computers).
 | DB9 pin D-SUB female to PC1 |
 | DB25 pin D-SUB female to PC2 |
| DB9 | DB25 | ||
|---|---|---|---|
| Receive Data | 2 | 2 | Transmit Data |
| Transmit Data | 3 | 3 | Receive Data |
| Data Terminal Ready | 4 | 6+8 | Data Set Ready + Carrier Detect |
| System Ground | 5 | 7 | System Ground |
| Data Set Ready + Carrier Detect | 6+1 | 20 | Data Terminal Ready |
| Request to Send | 7 | 5 | Clear to Send |
| Clear to Send | 8 | 4 | Request to Send |
Note: DSR & CD are jumpered to fool the programs to think that they are online.
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