NAME    [Toc]    [Back]

       sane-usb - USB configuration tips for SANE

DESCRIPTION    [Toc]    [Back]

       This  manual  page  contains  tips and tricks on how to access scanners
       with a USB interface.

GENERAL INFO    [Toc]    [Back]

       Sane-backends currently use three methods  of  communicating  with  USB
       scanners:

       - Using	libusb	(a library for usb access). This is used by the sm3600
	 backend currently.

       - Access through  sanei_usb,  the  SANE	USB  interface.  Used  by  the
	 mustek_usb, plustek, snapscan, and umax1220u backends.

       - Direct  access to the USB device files to access kernel scanner drivers.
 Used by the epson backend.

       This manual  page  describes  the  access  of  USB  scanners  over  the
       sanei_usb  interface.  For point one and three of this list have a look
       at the backends' manual pages for details.

       Currently USB access is only tested for Linux, FreeBSD and OpenBSD. For
       installation, also check the /usr/doc/sane-1.0.7/README.platform files.

       For scanners with a USB interface, it may  be  necessary  to  edit  the
       appropriate  backend configuration file before using SANE for the first
       time.  For most systems, the configuration file should list the name of
       the  USB  device  file  that  the  scanner is connected to (e.g., under
       Linux, /dev/usb/scanner0 or /dev/usbscanner0 is such a USB device,  the
       device file for FreeBSD is e.g.	/dev/uscanner0).  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.
  For a detailed  description  of	each  backend's  configuration
       file,  please  refer  to  the  relevant backend manual page (e.g. sanemustek_usb
 for Mustek USB scanners).

       For Linux, there is an alternate way  of  specifying  scanner  devices.
       This  alternate allows to identify scanners by the USB vendor and product
 numbers.  The syntax for specifying a scanner in 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
       looking	at  the  output  of  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. The same config line in decimal format looks like this:

	      usb 0x055f 0x0006

       When  using  a  USB scanner, ensure that the access permissions for the
       USB device are set appropriately.  We recommend to add a  group	"scanner"
  to /etc/group which contains all users that should have access to
       the scanner.  The permission of the device should then be set to  allow
       group  read  and  write	access.  For example, if the scanner is at USB
       device /dev/usb/scanner0, then the following two commands would set the
       permission correctly:

	      $ chgrp scanner /dev/usb/scanner0
	      $ chmod 660 /dev/usb/scanner0

ENVIRONMENT    [Toc]    [Back]

       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.

SEE ALSO    [Toc]    [Back]

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

AUTHOR    [Toc]    [Back]

       Henning Meier-Geinitz. Some parts were copied from the sane-scsi manual
       page.



				  03 Jan 2002			  sane-scsi(5)