UPS monitoring using RS-232 line

There is an industrial standard for using a serial port to monitor UPS systems (eg. APC !)

BD9 connector pinout

Pin 2  :  Mains Fail
    4  :  Common
    5  :  Battery Low
    6  :  Shutdown

This is the connection to a DB9, you can obviously convert this to a DB25 connection !

The output of the UPS is Normally Open, going close for Fault Condition !

The Shutdown feature is a RS232 +level signal asserted from the Host PC for 1 sec to shut the UPS down....

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This information was collected from UPS serial cable pinout discussion in sci.electronics.design newsgroup April 1997.
I have not tested this information so there is no guarantee on the correctness of this wiring.