[Nut-upsdev] Re: CyberPower 685AVR and newhidups

Peter Selinger selinger at mathstat.dal.ca
Tue Nov 1 03:23:57 UTC 2005


Charles Lepple wrote:
> 
> > > However, we only have a variable for "power", and often UPS
> > > manufacturers don't distinguish between VA and apparent power.
> 
> should have been clearer here: it is hard to tell between VA and
> apparent power *in the protocol stream* if the UPS manufacturer hasn't
> made a distinction somehow.

Actually, in the USB protocol, there is a distinction, because the HID
specification for power devices specifies two separate Usages:
"ApparentPower" (which is peak-to-peak VA) and "ActivePower" (in W,
also known as RMS VA).

-- Peter



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