Nut upsdev - Nov 2008 - Battery Volts shown as 20+ on Cyber Power UPS CP1000AVRLCD

Nut Developers,

	I have unsuccessfully tried to solve a problem with the voltage value on my
Cyber Power UPS CP1000AVRLCD. Something is wrong with the battery voltage
calculation. It always reads around 20 volts with that's nuts (pardon the
pun).
Right now:

battery.voltage	:	20.3

	You can take a look for yourself at http://www.3111skyline.com/nutindex.html

	Is there a parameter I can check or adjust to get the voltage down where it
should be? (Heck, I wouldn't mind just finding where the variable is stored
and
subtracting 8).

	Thanks for any help you can give.

-- 
David C. Rankin, J.D.,P.E.      |          openSoftware und SystemEntwicklung
Rankin Law Firm, PLLC           |             Countdown for openSuSE 11.1
www.rankinlawfirm.com           |        http://counter.opensuse.org/11.1/small

Citeren "David C. Rankin" <drankinatty at suddenlinkmail.com>:
> 	I have unsuccessfully tried to solve a problem with the voltage value on
my
> Cyber Power UPS CP1000AVRLCD. Something is wrong with the battery voltage
> calculation. It always reads around 20 volts with that's nuts  
> (pardon the pun).
> Right now:
>
> battery.voltage	:	20.3
>
> 	You can take a look for yourself at
http://www.3111skyline.com/nutindex.html
>
> 	Is there a parameter I can check or adjust to get the voltage down where
it
> should be? (Heck, I wouldn't mind just finding where the variable is  
> stored and
> subtracting 8).
The only calculation that is involved is done in the UPS. Per the HID  
PDC specification, NUT reports the HID path  
'UPS.BatterySystem.Battery.Voltage' as is. As such, the firmware in  
your UPS is broken, as it doesn't meet the HID PDC specifications.  
Complain to TrippLite if you wish.

Most likely, this will indeed require a correction to get to the  
actual battery voltage. We already knew that and most likely this will  
require two parameters in first order equation to get to

     battery.voltage = A x reported value + B

where A and B are to be determined. Which brings us to the problem  
that we will need at least two sets of reported versus actual  
battery.voltage to get to these. It could be that A is 1 and B is -8  
(your guess now), but we would need some measurements with a  
sufficiently accurate measuring device to find these.

The person that reported this issue before was either unwilling or  
unable to provide these, so unless you are, this is likely going to  
stay that way. If you're willing to work with us to solve this, please  
do. There already is a battery scaling for some other TrippLite units,  
so we could easily add this.

In any case we'll need the output of 'lsusb' and the output of the  
'usbhid-ups' driver running with debug level 2 (not higher).

Best regards, Arjen
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