1sane-usb(5)              SANE Scanner Access Now Easy              sane-usb(5)
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NAME

6       sane-usb - USB configuration tips for SANE
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DESCRIPTION

9       This  manual page contains information on how to access scanners with a
10       USB interface. It focusses on two  main  topics:  getting  the  scanner
11       detected by the operating system kernel and using it with SANE.
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13       This  page  applies  to USB most backends and scanners, as they use the
14       generic sanei_usb interface. However,  there  is  one  exceptions:  USB
15       Scanners  supported  by the microtek2 backend need a special USB kernel
16       driver, see sane-microtek2(5) for details.
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18

QUICK START

20       This is a short HOWTO-like section. For the full details, read the fol‐
21       lowing  sections.  The  goal  of  this  section  is  to get the scanner
22       detected by sane-find-scanner(1).
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24       Run sane-find-scanner. If it lists your scanner with the correct vendor
25       and  product  ids, you are done. See section SANE ISSUES for details on
26       how to go on.
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28       sane-find-scanner doesn't list your scanner? Does it work as  root?  If
29       yes, there is a permission issue. See the LIBUSB section for details.
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31       Nothing  is found even as root? Check that your kernel supports USB and
32       that libusb is installed (see section LIBUSB).
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USB ACCESS METHODS

36       For accessing USB devices, the USB library libusb is used.  There  used
37       to  exist  another  method  to  access  USB devices: the kernel scanner
38       driver. The kernel scanner driver method is deprecated and shouldn't be
39       used  anymore.  It  may be removed from SANE at any time. In Linux, the
40       kernel scanner driver has been removed in the 2.6.* kernel series. Only
41       libusb access is documented in this manual page.
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43

LIBUSB

45       SANE  can  only  use libusb 0.1.6 or newer. It needs to be installed at
46       build-time. Modern Linux distributions and other operating systems come
47       with libusb.
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49       Libusb  can  only access your scanner if it's not claimed by the kernel
50       scanner driver. If you want to use libusb,  unload  the  kernel  driver
51       (e.g. rmmod scanner under Linux) or disable the driver when compiling a
52       new kernel. For Linux, your kernel needs support for the USB filesystem
53       (usbfs). For kernels older than 2.4.19, replace "usbfs" with "usbdevfs"
54       because the name has changed. This filesystem must be  mounted.  That's
55       done  automatically  at  boot  time, if /etc/fstab contains a line like
56       this:
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58              none /proc/bus/usb usbfs defaults  0  0
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60       The permissions for the device files used by libusb  must  be  adjusted
61       for  user  access. Otherwise only root can use SANE devices. For Linux,
62       the devices are located in /proc/bus/usb/ or in  /dev/bus/usb,  if  you
63       use  udev.  There  are directories named e.g. "001" (the bus name) con‐
64       taining files "001", "002" etc. (the device files).  The  right  device
65       files can be found out by running scanimage -L as root. Setting permis‐
66       sions with "chmod" is not permanent, however. They will be reset  after
67       reboot or replugging the scanner.
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69       Usually udev or for older distributions the hotplug utilities are used,
70       which support dynamic setting of access permissions.  SANE  comes  with
71       udev and hotplug scripts in the directory tools/udev and tools/hotplug.
72       They can be used for setting permissions, see /usr/share/doc/sane-back‐
73       ends-1.0.24/README.linux, tools/README and the README in the tools/hot‐
74       plug directory for more details.
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76       For the BSDs, the device files used by  libusb  are  named  /dev/ugen*.
77       Use chmod to apply appropriate permissions.
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SANE ISSUES

81       This  section  assumes that your scanner is detected by sane-find-scan‐
82       ner. It doesn't make sense to go on, if this is  not  the  case.  While
83       sane-find-scanner  is  able  to detect any USB scanner, actual scanning
84       will only work if the scanner is supported by a SANE backend.  Informa‐
85       tion  on  the  level  of  support  can  be  found  on  the SANE webpage
86       (http://www.sane-project.org/), and the individual backend manpages.
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88       Most backends can detect USB scanners automatically using "usb" config‐
89       uration  file lines. This method allows to identify scanners by the USB
90       vendor and product numbers.  The syntax for specifying a  scanner  this
91       way is:
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93              usb VENDOR PRODUCT
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95       where VENDOR is the USB vendor id, and PRODUCT is the USB product id of
96       the scanner. Both ids are non-negative integer numbers  in  decimal  or
97       hexadecimal format. The correct values for these fields can be found by
98       running sane-find-scanner, looking into the syslog (e.g., /var/log/mes‐
99       sages)    or    under    Linux    by    issuing    the   command   "cat
100       /proc/bus/usb/devices".  This is an example of a config file line:
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102              usb 0x055f 0x0006
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104       would have the effect that all USB devices in the system with a  vendor
105       id  of  0x55f and a product id of 0x0006 would be probed and recognized
106       by the backend.
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108       If your scanner is not detected automatically, it may be  necessary  to
109       edit  the  appropriate backend configuration file before using SANE for
110       the first time.  For a detailed description of each backend's  configu‐
111       ration  file,  please  refer  to the relevant backend manual page (e.g.
112       sane-mustek_usb(5) for Mustek USB scanners).
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114       Do not create a symlink from /dev/scanner to  the  USB  device  because
115       this  link is used by the SCSI backends. The scanner may be confused if
116       it receives SCSI commands.
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ENVIRONMENT

120       SANE_DEBUG_SANEI_USB
121              If the library was compiled with  debug  support  enabled,  this
122              environment  variable  controls  the debug level for the USB I/O
123              subsystem.  E.g., a value of 128 requests all debug output to be
124              printed.  Smaller levels reduce verbosity. Values greater than 4
125              enable  libusb  debugging  (if   available).   Example:   export
126              SANE_DEBUG_SANEI_USB=4.
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128       SANE_USB_WORKAROUND
129              If your scanner does not work when plugged into a USB3 port, try
130              setting the environment variable SANE_USB_WORKAROUND to 1.  This
131              may  work around issues which happen with particular kernel ver‐
132              sions. Example: export SANE_USB_WORKAROUND=1.
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SEE ALSO

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

140       Henning Meier-Geinitz <henning@meier-geinitz.de>
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144                                  14 Jul 2008                      sane-usb(5)
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