[Nut-upsuser] Please help installing libusb-win32.

[Dmitry Donskoy]

Hello!

I have an UPS made by Powercom company; the model of the UPS is 
RPT-800A. This UPS has a USB port, which can be used to connect the UPS 
to a PC and read various data from the UPS (percentage of load, input 
voltage, output voltage, etc.).

So I download the NUT binary package for Windows, install and set it up 
using manual. Everything works fine for a few hours (I can get the data 
I need from my UPS using NUT).

And then NUT stops working. The error is "Data stale".

To read the data from UPS in Windows operating system (Windows OS), NUT 
uses the libusb-win32 library. When this library is installed, it 
substitutes the current USB device driver in Device Manager with its own 
custom libusb-win32 driver.

During my investigation of "Data stale" error of NUT, I open Device 
Manager and I see that "libusb-win32" device is disappearing and 
appearing again every 30 seconds approximately. It looks just like 
someone unplugs the UPS USB cable and plugs in again (but there is no 
indication of any actual disruption in physical connectivity).

I do really need to use NUT with this UPS (PCM RPT-800A).

How do I make this "libusb-win32" driver to be installed correctly so it 
won't disappear and appear in Device Manager by itself?