Hi All,

For a long time I was not able to make use from the buttons available on
the front pannel of my Acer 640BU scanner.
Finally I have investigated the problem using the USB sniffer when my
scanner was driven by a Windows machine.
I have found that the 640BU sends some specific packets
from its 3rd backend, when a button is pressed:

(252, 6, 0, 0, 0, 0, 0, 1) - for the 1st button
(252, 6, 0, 0, 0, 0, 0, 8) - for the 2nd button
(252, 6, 0, 0, 0, 0, 0, 32) - for the 3rd button

Sometimes also (252, 6, 0, 0, 0, 0, 0, 4) packet is sent (it seems, that
it is generated, when you press a button while scanner is still busy).

Basing on this observation, I have written a quick, dirty & simple utility
for batch scanning (it scans next page, when you press the left button,
it quits, when you press the right button).
The sources may be found on the "alt.sources" usenet group (subject:
Button controlled batch scanning utility for Acer 640BU).
The link is also here:

HTH & Regards,
Wojtek Zabolotny