Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!nrl-cmf!ukma!tut.cis.ohio-state.edu!rutgers!att!mtuxo!mtgzy!mtgzz!drutx!blum
From: blum@drutx.ATT.COM (Mark Blumhardt)
Newsgroups: comp.unix.questions
Subject: Re: UPS directed system shutdown info needed
Summary: another way
Message-ID: <10170@drutx.ATT.COM>
Date: 2 Feb 89 14:59:43 GMT
References: <210@wa3wbu.UUCP> <431@ispi.UUCP>
Organization: AT&T, Denver, CO
Lines: 17

In article <431@ispi.UUCP>, jbayer@ispi.UUCP (Jonathan Bayer) writes:
> In article <210@wa3wbu.UUCP> john@wa3wbu.UUCP (John Gayman) writes:
> >
> >    Does anyone have experience with interfacing a small UPS system (600-
> >1000VA) to a 386-based Unix box to allow for orderly system shutdown
> >when the batteries run down ?
> >
> What you want to do is to create a background daemon which will poll a
> serial port.  The serial port will be hooked up to the ups...

Another way, which may use less resources is to...hook the serial port to
the UPS, and connect (I cant remember exactly) ground and DTR.  Exec a
process that tries to open the port.  It will block (or return), depending
on the state of the contact closure.  After the return you can do a
graceful shutdown.

Mark