[sane-devel] Avision AV122 and reading the buttons gives I/O-Error

[Wilhelm Meier]

Hi,

does anybody how to read the option status of the two buttons of this 
type of scanner. The buttons on the device are labelled "Simplex" 
and "Duplex", but int the manual they read as "Cancel" and "Scan".

I want to modify the sanebuttonsd-daemon to get the status of these 
buttons. A look into the source of the avision backend told me, that 
they are handled through the OPT_MESSAGE option. 

But trying to read this option gives me:
...
[avision] sane_get_option_descriptor:
name: message, size: 129
[avision] sane_control_option: option=29, action=0
[avision] sane_control_option: option=message, action=GET
[avision] get_button_status:
[avision] ==> (interrupt read) going down ...
[avision] ==> (interrupt read) got: 0
[avision] get_button_status: interrupt read failed (Error during 
device I/O)
S   opt[29]: message =
[avision] sane_get_option_descriptor:
name: nvram-values, size: 1024
....

It is avision backend build 288.

Any hints.

-- 
Wilhelm