The dumpinquiry line causes some information about the camera to be printed.
cmdrespause specifies how many usec (1,000,000ths of a second) to wait between writing the command and reading the result. 125000 seems to be the lowest I could go reliably.
breakpause specifies how many usec (1,000,000ths of a second) between sending the "back to default" break and sending commands.
Empty lines and lines starting with a hash mark (#) are ignored. A sample configuration file is shown below:
@CONFIGDIR@/dc240.conf The backend configuration file (see also description of SANE_CONFIG_DIR below).
@LIBDIR@/libsane-dc240.a The static library implementing this backend.
@LIBDIR@/libsane-dc240.so The shared library implementing this backend (present on systems that support dynamic loading).
SANE_CONFIG_DIR This environment variable specifies the list of directories that may contain the configuration file. On *NIX systems, the directories are separated by a colon (`:'), under OS/2, they are separated by a semi-colon (`;'). If this variable is not set, the configuration file is searched in two default directories: first, the current working directory (".") and then in @CONFIGDIR@. If the value of the environment variable ends with the directory separator character, then the default directories are searched after the explicitly specified directories. For example, setting SANE_CONFIG_DIR to "/tmp/config:" would result in directories "tmp/config", ".", and "@CONFIGDIR@" being searched (in this order).
SANE_DEBUG_DC240 If the library was compiled with debugging support enabled, this environment variable controls the debug level for this backend. A value of 128 requests maximally copious debug output; smaller levels reduce verbosity.
This backend borrows heavily from the sane-dc210 (5) backend by Brian J. Murrell which is based somewhat on the sane-dc25 (5) backend by Peter Fales.
The manpage was largely copied from the sane-dc210 (5) manpage.
More general comments, suggestions, and inquiries about frontends or SANE should go to the SANE Developers mailing list (see http://www.sane-project.org/mailing-lists.html for details). You must be subscribed to the list, otherwise your mail won't be sent to the subscribers.