SANE2 was: Re: [sane-devel] Infrared channel

[Johannes Meixner]

Hello,

On Feb 22 11:29 m. allan noah wrote (shortened):
> > At the moment it is simply ignored when particular models require
> > special settings in <backend>.conf
> 
> unfortunately, this can be difficult to deal with, since what
> each model needs can vary drastically. cheaper models that require
> firmware to be loaded come to mind, and some models do crazy things
> like change usb ID or name after the firmware is loaded.

I forgot to mention that we do some guessing which models actually
require firmware upload and if yes we show a message to the user.
As we cannot distribute firmware it would not help to know
the syntax how to specify firmware upload in <backend>.conf
simply because we cannot provide the firmware.
I.e. in case of required firmware upload the user must set up
his device manually.

Firmware upload is a good example of missing information
in the *.desc files:

a)
As far as I know all scanners which use the backend gt68xx
and the related backend artec_eplus48u require a firmware upload,
I read "man sane-gt68xx" and "man sane-artec_eplus48u" and
http://www.meier-geinitz.de/sane/gt68xx-backend/
but I cannot be sure because there might be scanners
which use those backends but have built-in firmware.

b)
As far as I know all USB scanners (but not the SCSI scanners)
which use the backend snapscan require firmware upload according
to "man sane-snapscan" and http://snapscan.sourceforge.net/
but again I cannot be sure because there might be SCSI scanners
without built-in firmware or USB scanners with built-in firmware.

c)
There might be other scanners which require firmware upload
but when it is not mentioned in "man sane-<backend>" I would
miss such models.

If the location of the firmware on the manufacturer CD is fixed
and known then the location should be in the *.desc file
so that a config tool could get the firmware from there.

If the manufacturer provides firmware explicitely under a free
license for download then the URL should be in the *.desc file
so that a config tool could download the firmware.



> ok, i have played with ppd only a little, but it does seem to work. the
> problem comes with new scanners, or re-badged scanners. the current system of
> loading every backend in turn, and letting them use a back-end specific way to
> determine if they support the scanner gives us more flexibility than a ppd
> file for each know model.

Of course.
At the moment the problem for a scanner config tool is that the
backends do their stuff somehow "secretly".
Therefore all a scanner config tool can do is to activate the
backend in dll.conf and hope for the best.



> > I would like when the manufacturers of such devices could make
> > SANE backends easily - i.e. the SANE frontend must support
> > to connect to a network-scanner (e.g. specify the IP address
> > and the port etc.).
> 
> you could write a sane backend that did this, but you would need
> one for every different network transmission proto.

As the manufacturers of such devices should do it, it is perfectly
o.k. when each kind of network-scanner needs a matching backend.
It is the same as for the different kind of desktop scanners.

To set up many network-scanners in a business environment there
would be a scanner-server with a saned running and the user
workstations would only run the net meta-backend.

It is very similar to printing.
Even security (of saned) is not such a big problem.
When the users must have physical hardware access,
you must be in a trusted environment (internal network).


Kind Regards,
Johannes Meixner
-- 
SUSE LINUX Products GmbH, Maxfeldstrasse 5      Mail: jsmeix@suse.de
90409 Nuernberg, Germany                    WWW: http://www.suse.de/