[Nut-upsuser] UPS Liebert GXT-3

[Paul Smith]

Kris Jordan <nut.kj <at> sagebrushnetworks.com> writes:

> 
> Marcelo Roccasalva wrote, On 3/1/2013 12:10 PM:
> > On Thu, Feb 28, 2013 at 6:17 PM, Marcelo Roccasalva <roccas <at> 
gmail.com> wrote:
> >> On Tue, Feb 26, 2013 at 10:56 PM, Charles Lepple <clepple <at> 
gmail.com> wrote:
> >>> On Feb 21, 2013, at 6:21 PM, Marcelo Roccasalva wrote:
> >>>
> >>>> I'll try the windows monitoring program tomorrow...
> >>> Any luck?
> >> Haven't tried... An Emerson support person sent me an updated version
> >> of their software, which offers me an USB port to connect but it fails
> >> to communicate with the UPS... Tomorrow will be windows tested...
> > windows xp software tells me I need an UPS connected for the software
> > to work... The usb port has to be damaged... Thanks for your support.
> 
> Does Windows even notice the USB connection being made? Try resetting 
> the UPS by unplugging, disconnecting batteries, and pressing/holding all 
> the buttons to make sure the UPS is completely discharged. Does that help?
> 


Hi all,
   if I can just inject into this thread - I am willing to help if I can...

I just purchased an Emerson/Liebert PSA UPS with USB interface and wanted it 
to power my NAS Box (running FreeNAS 8 - a FreeBSD implementation), and have 
found similar issues with my UPS. From reading around and from what I can 
see for myself, it does appear that the underlying problem is that the HID 
descriptor is > 255 bytes and that somewhere in the USB driver chain there 
is code that expects it to be 255 bytes or less and gives up when it comes 
across something larger.

My issue is that I don't understand enough about FreeBSD USB or NUT in order 
to ascertain what needs "fixing", but I am confident that the root cause is 
the length of the HID Descriptor.

So, is the problem in NUT, or is the problem in the underlying USB drivers? 
How do we find out, and what do we do to fix?

I will try and get some output from my UPS when I get home tonight and will 
post back.

Best Regards,
Paul Smith