|
UPS Pin Number |
UPS Pin Name |
Direction |
Computer Pin Number |
Computer Pin Name |
Description |
|---|---|---|---|---|---|
| n/a | Shield | -- | n/a | Shield | Frame/Case Ground |
| 1 | Remote Shutdown | <-- | 7 | RTS | Kill UPS Power |
| 3 | Normally Open On-Battery Contact | --> | 8 | CTS | On Battery |
| 4 | Alternate Remote Shutdown | <-- | 3 | TxD | Alternate Kill UPS Power |
| 5 | Normally Open Low-Battery-Alarm Contact | --> | 1 | DCD | Low Battery |
| 9 | Signal Ground (Common) | -- | 5 | GND | Ground |
| * | <-- | 4 | DTR | DTR set to +5V by software |
* -- computer pin 4 (DTR) is connected to computer pin 1 (DCD) via the resistor 10k, and also it is connected to computer pin 8 (CTS) via the resistor 10k.
UPS (DB9M) IBM PC (DB9F)
----------- -------------
Shutdown 1 <------------------------------------------< 7 RTS
Alt Shutdown 4 <------------------------------------------< 3 TxD
Common 9 <------------------------------------------< 5 GND
PWR_FAIL 3 <---------------------------+--------------< 8 CTS
[#] R1 10k
+--------------< 4 DTR
[#] R2 10k
LOW_BATT 5 <---------------------------+--------------< 1 DCD
correct
incorrect