[sane-devel] canon dr-7550c batch scan only scans single page

[m. allan noah]

On Tue, Apr 13, 2021 at 9:43 AM <sanedevel at onderneming10.net> wrote:
>
> From: m. allan noah <kitno455 at gmail.com>
> Date: Tue, Apr 13, 2021 at 09:17:05AM -0400
> > On Tue, Apr 13, 2021 at 8:39 AM <sanedevel at onderneming10.net> wrote:
> > >
> > > From: m. allan noah <kitno455 at gmail.com>
> > > Date: Tue, Apr 13, 2021 at 08:28:24AM -0400
> > > > Interesting- the scanner reports it does not have any more paper in
> > > > it. Some questions:
> > > >
> > > > 1. does this happen if source=ADF Front?
> > >
> > > Yes, no difference, but only one face of the first page gets scanned, of
> > > course.
> > >
> > > > 2. does the second sheet of paper get pulled into the scanner when the
> > > > error occurs?
> > >
> > > No, it doesn't.
> > >
> > > > 3. does this happen at lower resolution?
> > >
> > > I see no difference at --resolution 100. Still lower resolutions don't
> > > really make sense. Higher resolutions (600) make no difference either.
> > >
> > > This is a large, bulk volume scanner. On executing the scanimmage
> > > command, the bottom of the tray moves up so the paper on top touches the
> > > rollers. After the first page, the tray moves back down. Trying to keep
> > > the paper up at the same level doesn't make any difference.
> > >
> > > Thanks,
> > > Jurriaan
> >
> > I think the version you are running might have a buffermode option?
> > Can you try enabling that, and see if the feeder stays up?
> >
> It didn't, so I added the pa:sane-project/sane-git repository and I
> retested with these versions:
>
> ii  libsane:amd64                          1.0.32+git20210410-focal0 amd64        API library for scanners [transitional package]
> ii  libsane-common                         1.0.32+git20210410-focal0 all          API library for scanners -- documentation and support files
> ii  libsane-hpaio:amd64                    3.20.3+dfsg0-2 amd64        HP SANE backend for multi-function peripherals
> ii  libsane1:amd64                         1.0.32+git20210410-focal0 amd64        API library for scanners
> ii  sane                                   1.0.14-15 amd64        scanner graphical frontends
> ii  sane-utils                             1.0.32+git20210410-focal0 amd64        API library for scanners -- utilities
>
> sudo scanimage -v --mode=Gray --batch --batch-count 999 --format=tiff -y 297 --buffermode=yes --page-height 297 --resolution 600 '--source=ADF Duplex'
>
> and lo and behold, that did make a large difference - it works.
>
> Thanks,
> Jurriaan
>

Sounds good. It has been many years since I had access to one of these
scanners with an elevator. In the past, that buffermode option was not
required to make it work. Perhaps something changed in the interim. I
suppose we could try to find it by using git bisect, but I am not sure
it is worth the effort.

allan
-- 
"well, I stand up next to a mountain- and I chop it down with the edge
of my hand"