[sane-devel] Re: HP 4570c - progress report

[Daniel Franke]

On Monday 19 September 2005 22:03, Bertrik Sikken wrote:

> I think you are currently the person who knows most about this
> scanner protocol :)

Ups ... errr, yes ...


> > I'll give them a try ... IIRC, I've observed that at some point in the
> > logs 0x1b01 was sent to the device, but 0x1b00 was read when the
> > previous command was read back. I'll have to double check this.
>
> I have seen this in the hp5400 logs too.
> When I looked at them, the lower byte of the command was a bit
> unclear, seems like some sort of parameter for the command
> specified in the upper byte.

I'd second this, in addition: the command to re-read the previous command 
doesn't actually return the full command (i.e. major and minor command id's), 
but the major command id and an error status.

For example:
Command 0xf00b is send to the device, then 0xf0 is the major command and 0x0b 
is kind of subcommand, the minor command number (I'm making these names up as 
I go along). Verifying the command returns 0xf000 instead of 0xf00b -- which 
means that the command 0xf0 succeded (second byte equals 0x00), the second 
byte does not equal 0x00 on error (e.g. happens while warming up the lamp).


> There are many versions of the usb sniffer log tools.
> The one that Allan recommends is indeed a good one.

Yes, I'm using sniff-bin (together with the awk-script) now, loads of bytes, 
but I'm getting along -- let's see how far =)


Regards
	Daniel