Subject: Re: UPS Backups
To: None <davagatw@Mars.utm.edU>
From: Masami and Ken Nakata <masami@fa2.so-net.or.jp>
List: port-mac68k
Date: 02/19/1997 08:16:47
On Tue, 18 Feb 1997 15:15:16 -0600 (CST),
"The Great Mr. Kurtz [David A. Gatwood]" <davagatw@Mars.utm.edU> wrote:
> 1. What VA rating would you suggest to achieve that (the system's power
> supply is rated at 3 amps max, no idea what the real drain is, though),

You mean VAh?  But sorry, I can't say anything about this.

> 2. How hard is it to set up LAN signalling on a free unix clone (i.e. is
> powerd or the equivalent available in source code form, and if not, how
> hard would something like that be to write)? 

This is not so hard.  I once did an instant automatic shutdown wiring
for a Pentium CGI server I set up for some fuel company's Web-based
polling system.  It was running FreeBSD 2.1.0, though.

Anyway, the APS' UPS we used had an RS232-level signal output which
got grounded when the AC power went down.  I connected the signal to
one of the serial port, and wrote a small daemon which periodically
polled for the status of the line.  If it went down, the daemon would
bring the server down by "shutdown -h now".  We never had to really
use it during the Web-polling operation, but I tested it a couple of
times (yanked the plug out) and it worked beautifully.

Hope this helps,

Ken