[sane-devel] Identifying identical scanners dynamically turned on and off

[Martin Zackrisson]

My problem is this:

I will have 2-4 identical scanners attached to the same computer. Due to 
the needs of the application, the power to the scanners will be cut and 
turned on automatically by the computer when they are to scan. All 
scanners will be doing this,  turn on - scan - turn off, in parallel 
several times per hour. I can not know if they will be on at the same 
time nor if the order will stay the same.

So what I'd like to do, since they will be plugged into specific 
USB-ports, is to identify them by their physical port. But how to do 
this so a normal user has rights to communicate with the scanner in a 
safe manner? I haven't seen any information when investigating the 
scanner(s) as to their physical port/position. It might be that I 
haven't succeeded fully to agree with udev.

At present only one scanner is attached and that works wonderfully but I 
call it without specifying device.

Scanner-brand: Epson V700