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Date:      Mon, 26 Nov 2001 01:15:39 -0800
From:      "Ted Mittelstaedt" <tedm@toybox.placo.com>
To:        <kjell@la3sg.net>, <freebsd-questions@FreeBSD.ORG>
Subject:   RE: Dumb UPS support under FreeBSD?
Message-ID:  <002901c1765a$ea4c7ce0$1401a8c0@tedm.placo.com>
In-Reply-To: <3C01F367.8646.DBFD8@localhost>

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>-----Original Message-----
>From: owner-freebsd-questions@FreeBSD.ORG
>[mailto:owner-freebsd-questions@FreeBSD.ORG]On Behalf Of Kjell
>Sent: Sunday, November 25, 2001 11:47 PM
>To: freebsd-questions@FreeBSD.ORG
>Subject: Dumb UPS support under FreeBSD?
>
>
>List members!
>
>I am looking for a program that will work with my (Liebert) dumb UPS
>that will perform an orderly shutdown of my computer by power fail, and
>turn it back on again when power returns.
>
>I have spent some time with the bkpupsd program, and found that it
>turns the UPS off at the same time it calls shutdown. Thus shutdown
>does not get time to sync discs etc.. This renders bkpupsd useless for
>machines with both latching (AT) and soft (ATX) power switches.
>
>I have found the mgeupsd and upsd programs in the ports collection.
>Does anyone have any experience with these programs?
>
>Are there any other programs I may use? After some modification?
>

The difference between your Liebert dumb UPS and the APC dumb BackUPS (which
is
what bkpupsd program is written for) is that APC put a timer in the BackUPS,
so that when the BackUPS receives the signal to shut itself off, it waits for
a set period of time before actually doing it.  Obviously the Liebert just
shuts off immediately.

If you have an ATX system that will indeed power itself off with bkpupsd, then
you can change your UPS cable connections so that instead of the turn-off
line being connected to DTR or CTS of the com port, it's instead connected to
something like the 5v+ of the mouse port.  Of course you will want to
put in a 1K protection resistor or something like that so that you don't blow
up the mouse port.  The idea here is that this power will disappear when the
ATX system shuts off completely by which it will then be safe to shut off the
Liebert.  Your going to have to do a little probing with a VOM to confirm
that.

If, however, you have an AT system then you have a problem because logically
it's impossible for a program to be written that toggles off the serial port
AFTER the system is completely stopped - because once the system is stopped
then programs cannot run, and since the system will still be powered and in
operation, there's not going to be anything you can sense that is going to
change
state then.

What you will need then is a black box that on receipt of a logic 0 from the
com port controlled by bkpupsd, will wait a spell then signal it's own logic 0
to the Liebert.  This could be anything from some relays and a capacitor, to
something totally electronic built around a 555 chip.


Ted Mittelstaedt                                       tedm@toybox.placo.com
Author of:                           The FreeBSD Corporate Networker's Guide
Book website:                          http://www.freebsd-corp-net-guide.com



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