Nut upsuser - Oct 2007 - APC Back-UPS ES 550 reports zero(0) load

Hi Folks,

I just bought two APC UPSes, an EX 1300 and an ES 550 for two
different sites and installed NUT for the first time on two machines
(one Centos 4.1, the other Ubuntu 7.04).  So far I'm well impressed --
excellent work by the dev team!  The EX 1300 is working beautifully
with NUT on the Centos box, but I'm having a bit of a problem with the
ES 550: even while loaded, the ups.load value reported by upsc and
other tools is always zero (see upsc.out, attached).  I've also
attached the debugging info from usbhid-ups.

Both instances are running the latest stable release, built on the
aforementioned machines.    I realize that the different models of
UPSes could have wildly different capabilities/reporting options
w.r.t. to NUT, but I spent a couple of days searching the mailing list
archives and haven't encountered anyone else describing a similar
situation with the ES series, which is odd 'cos they appear to be
pretty popular deskside UPSes.  I can't be the only one using one with
an Ubuntu machine...

Any help or guidance would be appreciated.  If I need to patch the
source to add support for the ES 550, I can do that, with a little
guidance.

Cheers,
Ben
-- 
Ben Steeves                               ben.steeves at unb.ca
                                          GTalk: ben.steeves
http://www.metacon.ca/bcs                 GPG ID: 0xB3EBF1D9
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> Any help or guidance would be appreciated.  If I need to patch the
> source to add support for the ES 550, I can do that, with a little
> guidance.
There is nothing we can do about this. According to the output you
attached (which is great, thanks), the UPS is reporting this.

Path: UPS.PowerConverter.PercentLoad, Type: Feature, ReportID: 0x50,
Offset: 0, Size: 8, Value: 0.000000

We can't tell if the load is really zero or not, so if the UPS provides us
with bogus data, this will be displayed as is.

Best regards, Arjen
-- 
Eindhoven - The Netherlands
Key fingerprint - 66 4E 03 2C 9D B5 CB 9B  7A FE 7E C1 EE 88 BC 57

On 10/12/07, Arjen de Korte <nut+users at de-korte.org>
wrote:
>
> > On 10/12/07, Arjen de Korte <nut+users at de-korte.org> wrote:
> >> > Any help or guidance would be appreciated.  If I need to
patch the
> >> > source to add support for the ES 550, I can do that, with a
little
> >> > guidance.
> >>
> >> There is nothing we can do about this. According to the output you
> >> attached (which is great, thanks), the UPS is reporting this.
> >>
> >> Path: UPS.PowerConverter.PercentLoad, Type: Feature, ReportID:
0x50,
> >> Offset: 0, Size: 8, Value: 0.000000
> >
> > Arjen,
> >
> > is there a possibility that the descriptor has some strange conversion
> > that is causing NUT to read this improperly? I don't recall if
there
> > is a way to display the hex values coming back from the device.
>
> Well, the version from the trunk or Testing will display this at debug
> level 3 or higher. At debug level 5 or higher it will even display the
> values for the logical to physical conversion that was used in the
> calculations. But looking at the size of it (8 bits) I don't think
> PercentLoad will require a conversion. Theoretically you could increase
> the resolution from 1% to ~0.4% (100/256) though, but this feature is
> rarely used.
Based on the increased debugging output, it doesn't look good:

parsing PercentLoad
Looking up PercentLoad
hid_lookup_usage: found 840035
Path depth = 3
0: Usage(00840004)
1: Usage(00840016)
2: Usage(00840035)
Entering libusb_get_report
Report[r]: (2 bytes) => 50 00
=>> Before exponent: 0, 0/0)
=>> After conversion: 0.000000 (0), 0/0)
Path: UPS.PowerConverter.PercentLoad, Type: Feature, ReportID: 0x50,
Offset: 0, Size: 8, Value: 0.000000

When I'm back at the site, I'll try hooking up a laptop with APC's
software and see if it can read the value... maybe the UPS just
doesn't report the load correctly at all...
--
Ben Steeves                               ben.steeves at unb.ca
                                          GTalk: ben.steeves
http://www.metacon.ca/bcs                 GPG ID: 0xB3EBF1D9