| UPS Signal Name | DB-9 Male (UPS end) | DB-9 Female (PC end) | PC Signal Name | 
| RxD | 1 | 3 | TxD | 
| TxD | 2 | 2 | RxD | 
| GND | 5 | 5 | Common ground | 
| GND | 4 | 7 | RTS | 
 
| UPS Signal Name | DB-9 Male (UPS end) | DB-9 Female (PC end) | PC Signal Name | 
| RxD | 1 | 3 | TxD | 
| TxD | 2 | 2 | RxD | 
| GND | 5 | 5 | Common ground | 
| GND | 4 | 7 | RTS |