[sane-devel] Two USB attached scanners

[Klaas Freitag]

On Tue, 23 Apr 2002, Henning Meier-Geinitz wrote:

hi,

> > It keeps telling me I can only have ONE scanner attached via SANE and toi
> > choose which one to install.
> > Surely this cannot be true!
>
> Just to clearify this: SANE can use an unlimited number of scanners
> (and other devices) by design. Some backends can only use one scanner
> at the same time but most support more than one.
>
> Maybe the SuSE installer is just not smart enough :-)

The problem is that the installer usually writes device filenames and they can
change. Consider scanner1 on /dev/usb/scanner0 and scanner 2 on
/dev/usb/scanner1. The installer writes the filenames into the config files. Now
you remove scanner1. That makes the kernel immediately move scanner2 to
/dev/usb/scanner0! That is the real problem. The device file changes. That is
why it was decided only to support one USB scanner with the install tool. Note
that you can handle one USB and more SCSI scanner, and I think that is more
usual case having the old SCSI scanner and bought a new cool USB scanner ;).

As long as all scanners are connected to the machine and you do not unplug it,
it works.
>
> Usually you can even do this. I tried this some time ago and managed to scan
> from 5 devices at the same time (2 SCSI, 2 USB and 1 with a
> proprietary card).
Wow, cool ;-)) I only managed three, which was USB, SCSI and Network.

Klaas
>

-- 
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 Ja mach nur einen Plan und sei ein grosses Licht         Klaas Freitag
 dann mach noch einen zweiten Plan    *            mail freitag@suse.de
 gehn tun sie beide nicht. - B. Brecht             SuSE Labs, Nuernberg
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