connector or cable wiring
9 pin D-SUB male connector to
the UPS
9 pin D-SUB female
connector to the computer
| UPS Signal Name | DB-9 Male (UPS end) | DB-9 Female (PC end) | PC Signal Name |
|---|---|---|---|
| RxD | 1 | 2 | |
| AC Fail | 2 | 9 | Contact closure |
| n/a | 3 | 1 | not used |
| GND | 4 | 5 | Common ground |
| Bat Low | 5 | 6 | Contact closure |
| TxD | 6 | 3 | |
| GND | 7 | 8 | |
| RTS | 8 | 7 | |
| DTR | 9 | 4 |
Notes
- AC Fail and Bat Low - normally open (shorted to GND when active).