connector or cable wiring APC part # 940-0119A
9 pin D-SUB male connector to
the PC
9 pin D-SUB male connector to
the UPS
The BackUPS ES has a straight through serial cable with no identification on the plugs.
computer ----------- BackUPS-ES -----------------
DB9-M DB-9F
pin signal pin
4 DSR -> 4 --+
| diode resistor
6 DTR -> 6 --+---->|----/\/\/\---o kill power
1 DCD <- 1 --+
|
2 RxD <- 2 --+----------------+--o low battery
|
7 RTS -> 7 --------+--/\/\/\--+
|
+--/\/\/\--+
|
8 RI <- 8 --+----------------+--o on battery
|
9 CTS <- 9 --+
5 GND --- 5 ----------------------o ground
3 TxD 3 nc