[cups.general] RAW queue en 9100 printing

[Helge Blischke]

Dennis Leeuw wrote:

> On 02/28/2013 12:47 PM, Helge Blischke wrote:
>> Dennis Leeuw wrote:
>>
>>> Hi all,
>>>
>>> For all our windows printer queues we used to use IPP to the printer and
>>> a RAW queue on CUPS and that worked fine, till a couple of weeks ago we
>>> received a Xerox WC7556 printer. After a lot of tweaking and testing I
>>> found that the only solution to make it work is to use port 9100 + RAW
>>> printing.
>>>
>>> When we use IPP and RAW and we send a job that has to print 2 copies,
>>> only one is printed.
>>> When we use 9100 and RAW then all works fine.
>>>
>>> That fact that we found a solution is great, but I also would like to
>>> know why. Can someone explain to me what the difference is and how this
>>> works? Or can someone point me to the direction how to find out what
>>> goes on?
>>>
>>> We are using Windows XP, CUPS 1.4.3 on Ubuntu.
>>>
>>> Thanks in advance,
>>>
>>> Dennis Leeuw
>> I guess the IPP issue is due to the fact that in this case IPP job
>> attributes take precedence over the respective settings of the PostScript
>> job itself (an issue I already detected some time ago when using the java
>> based IPP implementation in Xerox DocuTech printers).
>> CUPS inserts a copies value of 1 in the printing IPP requests (as this is
>> the default) which corresponds to the command line options for the
>> filters and backends.
>> I then hacked the IPP backend (starting with 1.3.5) to discard the copies
>> attribute from the IPP request unless explicitely specified, so that the
>> copies spec in the PS job got activated again.
>> If you are interested, I could send you this (brute force) hack which
>> could easily adapted to the 1.4.3 backend, but you then need to get the
>> cups 1.4.3 sources, compile from the sources, and replace the original
>> ipp backen.
>>
>> Helge
>>
> 
> Thank you for your explantion this sounds exactly like what might be
> going on. For now the 9100 printing solution is workable.
> 
> I am going to put wireshark on the wire, to see if I can find the
> command where it says 1 copy instead of two. Sounds like another mistery
> solved.
> 
> Thanks,
> 
> Dennis

You only need to inspect the /var/spool/cups/cnnnnn files, where nnnnn is 
the respective job ID with leading zeros and look for "copies" and the 
following binary integer value.
On the other hand, within the PS job, there will be a PostScript statement 
like
#copies 2 def
or
/NumCopies 2 def
specifying your 2 copies, but CUPS doew not know about that.

Helge