Hi Valerio.
May be, I'm missing something, but I don't see something that looks like
scanner in your list of devices. May be, something wrong with USB port
or cable...
BTW, Lide 400 known to work via IPP over USB, and in this mode it
supports eSCL protocol.
You may try to install the following program for IPP over USB:
https://github.com/OpenPrinting/ipp-usb
Sorry, there are no Slackware binary packages, but this program is easy
to build.
After that program is installed, there are chances that it will work
with sane-escl, included officially into SANE. If not, there are
alternative eSCL/WSD backend, known to work (based on 2 user's reports)
with this device:
https://github.com/alexpevzner/sane-airscan
--
Wishes, Alexander Pevzner ([email protected])
