Hello David,
David Paschal wrote:
>
> > has someone running a HP Scanjet IIp (or another HP scanner) on Irix 6.2
> > ?
> > There is a problem with such a combination that the scanner is
> > recognized
> > during the SCSI INQUIRE command (vendor, model and firmware is read
> > back),
> > but the scanner does not give any response to other commands.
> > The TEST UNIT READY seems also to work.
> > Has someone encountered a similar problem on Irix and how was it solved
> > ?
>
> Hi, Peter. I don't know if this is related, but I had trouble with partial
> SCL responses when I was developing my experimental support for HP OfficeJets
> connected to HP JetDirect print servers (see http://www.ns.net/~paschal/sane).
oops, seems that I have missed a lot on the mailing list. Did not know
that these type of scanners even support SCL. I am currently thinking
about enhancing the backend for 16bit support (there have been some
patches before). Should I include your sources this time ?
> There were situations where the device apparently split up the SCL response
> into different packets, which caused read() on the client to return only the
> first part.
I would be glad if it would return anything.
> This caused a great deal of confusion with the upper levels of
> the HP SCL backend, due to both the short initial response, and the remainder
> of the response, which was interpreted as a malformed response to a subsequent
> request. I solved these problems by adding a select-and-read loop to my I/O
> code, with support for different timeouts for the first and subsequent
> select()s. See hp_jdex_read() and hp_jdex_select() in hp-jdex.c.
>
> Perhaps the ScanJetIIp/Irix6.2 problem is caused by a similar sensitivity
> in the HP backend to unusual timeout behaviour in the underlying OS, although
> it's strange that read() would return immediately with no data.
We tried to wait 1 second after each write. But it was no success.
> I wonder if
> the fd is somehow defaulting to non-blocking mode?
Sounds that this is located in the sanei-part. I should have a look at
it.
The funny thing is, that the SCSI-INQUIRY command seems to work, because
the vendor, model and firmware code is recognized. TEST UNIT READY also
works (gives no error back). But the scanner does not answer any other
command.
> Just speculating aloud
> here...
>
Just listening and thinking about it.
Peter
> David
>
> --
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-- Peter Kirchgessner WWW: http://www.kirchgessner.net e-mail: peter@kirchgessner.net-- Source code, list archive, and docs: http://www.mostang.com/sane/ To unsubscribe: echo unsubscribe sane-devel | mail majordomo@mostang.com
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