[Nut-upsdev] [nut-commits] svn commit r1043 - in trunk: . docs drivers

Peter Selinger selinger at mathstat.dal.ca
Sat Aug 11 23:43:38 UTC 2007


Arjen de Korte wrote:
> 
> + * drivers/apc-hid.c:
> +   - Commented out the 'fullycharged' status. If anyone can explain the
> +     use of this, please step forward.

This flag is defined on p.36 of the "Universal Serial Bus Usage Tables
for HID Power Devices", Release 1.0 November 1, 1997, a USB standards
document available on the web.

The document defines this flag to mean "Fully Charged". I assume that
this means that the battery is fully charged, which would presumably
happen after charging has finished, and before discharging begins. Its
meaning should be similar to a battery.charge of 100%, except that it
is a boolean flag, and that for whatever reason, some UPS might
consider itself fully charged at less than 100%.

FullyCharged is not precisely an "alarm", as it is not a condition to
be worried about. It is a kind of status. The standard actually
defines four related codes defined: "Charging", "Discharging",
"FullyCharged", and "FullyDischarged". Although some UPS simply
pretend to be "charging" all the time, this is often confusing to
users, who expect that their battery must be full at some point.
It would make sense to me to map all four related codes to status
flags. In fact, precisely one of the four should be true at any given
time for any given connected battery, although the standard does not
specify this. 

-- Peter



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