Re: UPS recomendation for specific needs?
From: Richard Corden (richard_corden_at_hotmail.com)
Date: Fri, 01 Apr 2005 09:12:35 +0000
>>Why strongly prefer Serial? The HOWTO and web pages I read about this
>>were recommending USB as there's no playing with the serial port to get
> Because USB is flakey. The connection disappears and only a cold
> power on restart will reconnect to the device. What good is a UPS if
> you can't monitor it?
> Moreover, my copy of nut says that USB is "experimental". I just say
> No Thanks to experimental.
> I just plugged my homemade cable in and it worked. Nothing at all had
> to be done to the serial port. Slackware 10.0.
It was actually the Slackware 10.1 HOWTO which recommended USB. Here's
the relevant part:
Another important consideration is how your UPS will communicate with
your computer. Do not buy a serial line UPS (one that communicates via
an RS-232C cable). These are passing out of use in favour of UPS
designs that use USB or Ethernet, for the very excellent reason that
RS-232C interfaces are flaky, difficult to configure, and difficult to
debug. Ethernet is overkill for this application; UPS' simply don't
need that kind of bandwidth. We recommend sticking with USB, which is
well-matched in price/performance to this job and relatively easy to
> Nobody is forcing anyone here to use serial rather than USB, but - in
> my experience - the serial user is likely to be a Happy Camper while
> the USB user is likely to be frustrated. YMMV
I know you are not forcing me to use serial. However, when spending
money, especially more than a couple of dollars/euros its nice to know
that you are buying the *right* solution.
I have no experience at all with UPS' so I must try rationalise these
points of view together. I have your word that Serial is better or the
HOWTO which says I should go with USB. I cannot judge whose right - and
you both pretty much say the same things, just interchanging 'USB' with
-- Richard Corden