[sane-devel] dell1600n-net backend

[Alessandro Zummo]

On Sun, 8 Jan 2006 15:16:38 +0000 (GMT)
Jon Chambers <jon at jon.demon.co.uk> wrote:

> This could be useful.  What scanner are you working on and what stage are 
> you at?  Do you know the network protocol?  Do you have a working 
> prototype?  Have you made a start on a SANE backend?

 Epson CX11NF. The protocol is ESC/I plus some encapsulation. I've a perl
 script to do some little things with it. Not yet started with the backend,
 I'm focusing on the transport.

> 1. Platform independent networking code.  Perl does a pretty good job of 
> hiding this.  C headers could potentially be more problematic. 
> (Certainly Linux and Win32 BSD socket functions differ - I don't know much 
> about other platforms).  A poke around the existing "net" backend would 
> probably be instructive.

 I agree. I only know of unix sockets, so probably the first version won't work
 straight on windows...

> 2. The app does not know how many pages will be received or their 
> parameters until the scanned pages arrive (ie: it can specify resolution 
> and format but the user may override these on the scanner front panel 
> before pressing "scan").  I have yet to figure out whether the SANE API 
> will be happy with this (eg: maybe it needs to allocate storage space for 
> the scan data before the scan starts).

 The CX11NF can be operated both from the panel and the host pc. No problems
 when doing that from the host, as you can use scanadf to process the pages.

 The panel interface is a bit different: the CX11 will send multicast
 packets to discover suitable hosts. The hosts will send the CX11 their
 name and the CX11 will show them on the panel. When the user presses the scan
 button, a packet will be sent to the host with the parameters. 
 
 I've handled this process outside of SANE, using some Perl code. scanadf
 is then called with the suitable parameters to actually perform the scan.

 (actually, I'm doing all of this data exchange via network, except the
 actual scan work which is done via USB).

> 3. The scan data arrives as either CCITT Fax Group 4 or JPEG format and so 
> will need converting to RGB in order to pass through the API.

 My scanner is already supported under USB, so my job will probably be
 a bit easier on this front.

-- 

 Best regards,

 Alessandro Zummo,
  Tower Technologies - Turin, Italy

  http://www.towertech.it