[argyllcms] Re: Problem accessing HCRF probe

  • From: Graeme Gill <graeme@xxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Fri, 24 Aug 2007 13:14:12 +1000

Frédéric wrote:

icoms: Write_Read called with '\377'
icoms: About to write '\377' ICOM err 0x0
icoms: Read called
icoms: About to return read '' ICOM err 0x2000
icoms: Write_Read Write failed - returning 0x2000
hcfr_command failed
hcfr: Error with getting or version of firmware
The instrument can be removed from the screen.
icoms: delete called
icoms: closing port
usb_close_port() called
usb port has been released and closed
Dispread: Error - dispread failed with 'Instrument Access Failed'

It is not a permission problem, because solved it (udev rule). And there are no messages in /var/log/messages...

I'm not sure I can help. I found the HCFR USB interface to be quite
unreliable at times, and often had to open the box up and hit the reset
switch a couple of times to get it recognized. On some platforms some
very subtle changes in the sequence of USB operations (interface resets etc.)
would cause it to work or not work. As far as I know it works on all
three platforms I've tested on currently. The fact that it says it's a
serial device causes problems on OS X, requiring a codeless kernel
extension to be installed to prevent it being captured by the operating
system. The above diagnostic sequence is what you see when it simpy isn't

For a beamer calibration, do you think I should use the 2.4mm aperture? Or is the default one ok? The probe will be at, say, 1m from the projection screen...

I'd leave the unit with it's default (wide open) arrangement for
a projector - this is what it was designed for, and it will
get more light and be faster this way.

BTW, why don't you use such cdc_acm driver for UNIX system? Does it exist only uder Linux? Is libusb better in this case?

I suspect it's a UNIX only thing, and I'm working cross platform,
and libusb is cross platform. All the other instruments I'm
dealing with need direct USB communication (ie. they don't
say they are a serial device), and I have a library built on top
of libusb for dealing with cross platform and instrument issues. It's
just too much trouble to support some other special access method that
will be different on each platform for the HCFR.

Graeme Gill.

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