sane-usb - USB configuration tips for SANE


   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.


   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 supports USB and
   that libusb is installed (see section LIBUSB).


   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.


   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 disable the driver when compiling a
   new kernel. For Linux, your 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

          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. Setting
   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 utilities are used,
   which support dynamic setting of access permissions.  SANE  comes  with
   udev and hotplug scripts in the directory tools/udev and tools/hotplug.
   They    can    be     used     for     setting     permissions,     see
   /usr/share/doc/libsane/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.


   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
   (, and the individual backend manpages.

   Most  backends  can  detect  USB  scanners  automatically  using  "usb"
   configuration  file  lines. This method allows one to identify 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".  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.


          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  debugging  (if   available).   Example:   export


   sane(7), sane-find-scanner(1), sane-"backendname"(5), sane-scsi(5)


   Henning Meier-Geinitz <>

                              14 Jul 2008                      sane-usb(5)


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.