[Nut-upsuser] Unsupported UPS Orvaldi 520PL?

Milan Knížek knizek.confy at gmail.com
Sun Aug 28 06:30:02 UTC 2011

Hello Charles,

V Sat, 27 Aug 2011 19:32:37 -0400
Charles Lepple <clepple at gmail.com> napsáno:

> On Aug 27, 2011, at 2:57 AM, Milan Knížek wrote:

> > I am no electrician: is it reasonable to expect that the UPS should
> > provide High/Low voltages on the appropriate pin pairs even without
> > having any cable power signal from the computer?
> "dry contact" means that the UPS does not supply voltage to the
> pins; rather, it closes and opens relay contacts. You can check the
> contacts with the meter set to measure resistance (or on a continuity
> setting).

I got the point now :-)

Nevertheless, the pins, which are indicated by the vendor's drawing as
to be closed circuit when AC on and battery normal are open all
the time anyway.

I also measured separately the cable and the serial port on UPS and all
seem in line with the drawing (few pins are closed through resistors or

So, the conclusion is the same and I will get another UPS (Eaton or
APC) for the server and use the Orvaldi for my desktop, where I do not
need the communication capability necessarily.

Thanks for the support and extra explanations of the fundamentals to a


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