UPS Signal Name |
DB-9 Male (UPS end) |
DB-9 Female (PC end) |
PC Signal Name |
Shutdown | 2 | 4 | DTR |
PWR Fail | 5 | 8 | CTS |
LOW BATT | 6 | 1 | DCD |
Common | 1,4 | 5 | GND |
Pin 7 at the PC end (RTS) connected by R1 2k0 to pin 8 (CTS) and connected by R2 2k0 to pin 1(DCD)