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Re: [LI] apc powerchute equivalent



"L.V.Gandhi" wrote:
> 
 
> I have safepower ups which also has provision connecting to serial port.
> Can anybody suggest some software to be used in linux?
> --
> L.V.Gandhi
> MECON, 5th Floor, RTC Complex, Visakhapatnam AP 530020 INDIA
> http://www.poboxes.com/lvgandhi  lvgandhi@xxxxxxxxxxx,
> lvgandhi@xxxxxxxx,  31882656@xxxxxxxxxxxxxxxxxxx
> 
> --------------------------------------------------------------------

Few months back I wrote a small howto on Shutdown Of linux box with a
switch. Here i was using powerd (found on most linux cd) to sense the
power down signal. I think I can shed some light on this UPS business.
There are two type of signal a UPS generates for power down.
1. A relay in UPS closes a contact  when power fails, and this contact
is used to lower the DTR signal of serial port of PC( there are various
combination). The powerd monitors this DTR signal and shuts down the PC
via inittab. In place of this relay I have put  small switch to shut
down my linux box as it does not have monitor or key board. 
2. The second type is where UPS transfers the important parameters like
line voltage, battery voltage and power fail signal by normal serial
port protocol. You require a special software to decode these messages.
How ever this is implemented in more sophisticated UPS only. 


-mukund
http://members.theglobe.com/betacomp/index.htm
http://members.xoom.com/BETACOMP/index1.htm


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