SANE Scanner Access Now Easy sane-usb(5)
NAME
sane-usb - USB configuration tips for SANE
DESCRIPTION
This manual page contains information on how to access
scanners with a USB interface. It focusses on two main
topics: getting the scanner detected by the operating system
kernel and using it with SANE.
This page applies to USB most backends and scanners, as they
use the generic sanei_usb interface. However, there is one
exceptions: USB Scanners supported by the microtek2 backend
need a special USB kernel driver, see sane-microtek2(5) for
details.
QUICK START
This is a short HOWTO-like section. For the full details,
read the following sections. The goal of this section is to
get the scanner detected by sane-find-scanner(1).
Run sane-find-scanner. If it lists your scanner with the
correct vendor and product ids, you are done. See section
SANE ISSUES for details on how to go on.
Sane-find-scanner doesn't list your scanner? Does it work as
root? If yes, there is a permission issue. See the LIBUSB
section for details.
Nothing is found even as root? Check that your kernel sup-
ports USB and that libusb is installed (see section LIBUSB).
USB ACCESS METHODS
For accessing USB devices, the USB library libusb is used.
There used to exist another method to access USB devices:
the kernel scanner driver. The kernel scanner driver method
is deprecated and shouldn't be used anymore. It may be
removed from SANE at any time. In Linux, the kernel scanner
driver has been removed in the 2.6.* kernel series. Only
libusb access is documented in this manual page.
LIBUSB
SANE can only use libusb 0.1.6 or newer. It needs to be
installed at build-time. Modern Linux distributions and
other operating systems come with libusb.
Libusb can only access your scanner if it's not claimed by
the kernel scanner driver. If you want to use libusb, unload
the kernel driver (e.g. rmmod scanner under Linux) or dis-
able the driver when compiling a new kernel. For Linux, your
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kernel needs support for the USB filesystem (usbfs). For
kernels older than 2.4.19, replace "usbfs" with "usbdevfs"
because the name has changed. This filesystem must be
mounted. That's done automatically at boot time, if
/etc/fstab contains a line like this:
none /proc/bus/usb usbfs defaults 0 0
The permissions for the device files used by libusb must be
adjusted for user access. Otherwise only root can use SANE
devices. For Linux, the devices are located in
/proc/bus/usb/ or in /dev/bus/usb, if you use udev. There
are directories named e.g. "001" (the bus name) containing
files "001", "002" etc. (the device files). The right device
files can be found out by running scanimage -L as root. Set-
ting permissions with "chmod" is not permanent, however.
They will be reset after reboot or replugging the scanner.
Usually udev or for older distributions the hotplug utili-
ties are used, which support dynamic setting of access per-
missions. SANE comes with udev and hotplug scripts in the
directory tools/udev and tools/hotplug. They can be used for
setting permissions, see /usr/doc/sane-1.0.19/README.linux,
tools/README and the README in the tools/hotplug directory
for more details.
For the BSDs, the device files used by libusb are named
/dev/ugen*. Use chmod to apply appropriate permissions.
SANE ISSUES
This section assumes that your scanner is detected by sane-
find-scanner. It doesn't make sense to go on, if this is not
the case. While sane-find-scanner is able to detect any USB
scanner, actual scanning will only work if the scanner is
supported by a SANE backend. Information on the level of
support can be found on the SANE webpage (http://www.sane-
project.org/), and the individual backend manpages.
Most backends can detect USB scanners automatically using
"usb" configuration file lines. This method allows to iden-
tify scanners by the USB vendor and product numbers. The
syntax for specifying a scanner this way is:
usb VENDOR PRODUCT
where VENDOR is the USB vendor id, and PRODUCT is the USB
product id of the scanner. Both ids are non-negative integer
numbers in decimal or hexadecimal format. The correct values
for these fields can be found by running sane-find-scanner,
looking into the syslog (e.g., /var/log/messages) or under
Linux by issuing the command "cat /proc/bus/usb/devices".
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This is an example of a config file line:
usb 0x055f 0x0006
would have the effect that all USB devices in the system
with a vendor id of 0x55f and a product id of 0x0006 would
be probed and recognized by the backend.
If your scanner is not detected automatically, it may be
necessary to edit the appropriate backend configuration file
before using SANE for the first time. For a detailed
description of each backend's configuration file, please
refer to the relevant backend manual page (e.g. sane-
mustek_usb(5) for Mustek USB scanners).
Do not create a symlink from /dev/scanner to the USB device
because this link is used by the SCSI backends. The scanner
may be confused if it receives SCSI commands.
ENVIRONMENT
SANE_DEBUG_SANEI_USB
If the library was compiled with debug support enabled,
this environment variable controls the debug level for
the USB I/O subsystem. E.g., a value of 128 requests
all debug output to be printed. Smaller levels reduce
verbosity. Values greater than 4 enable libusb debug-
ging (if available). Example: export
SANE_DEBUG_SANEI_USB=4.
SEE ALSO
sane(7), sane-find-scanner(1), " .}S 3 1 "sane-backendname""
"(5)," "" "" "" "" sane-scsi(5)
AUTHOR
Henning Meier-Geinitz
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
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SANE Scanner Access Now Easy sane-usb(5)
_________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|____________________|____________________________________|_
| Availability | image/scanner/xsane/sane-backends|
|____________________|____________________________________|_
| Interface Stability| Uncommitted |
|____________________|___________________________________|
NOTES
Source for SANE is available on http://opensolaris.org.
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