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White light sensor settings

Hi,

Yesterday the Optiv machine gave very strange values with the white light sensor. It recently gave me some problems with making surface points. The white light did not measure it, so I went on and changed the 'set detection treshold' value, which was on 205, to 80. I saved this setup and it worked perfectly well for a day, but then it started to give me strange values such as 0.4 out of tol for the flatness. My frequency is set on 320 Hz.

I would love to hear a solution for this, as I have to wait a week for the troubleshooter and the machine cannot be used in the meanwhile.

Mihael
  • The “set detect.threshold” is a setting in the optical sensor, not in PC-DMIS. We have a “CHRocodile S” made by Precitec. I was told by the Hexagon service engineer not to change any settings, so I never touch it. I don’t even feel comfortable scrolling through the menus, so I don’t know what our setting is.

    According to the manual, the range of settings is 0 to 999. Quoting the manual:

    If the distance to a surface with low reflectivity is measured, the intensity of the reflected light can be too low and the measurement rate must be reduced.
    For a measurement rate under 1 kHz, a threshold of 40 is recommended. This prevents measurement values of too low an intensity, which rise only slightly above the noise, which would falsify the measurement. At a measurement rate of 1 kHz and higher, a threshold of 15 is expedient in fully exploiting the device’s dynamics.

    In PC-DMIS the “SENSOR FREQUENCY” is set to 1000 in most of our programs.
  • Hi Rick,

    Thanks for the response. I found the problem today. I had to restart the machine when I changed the values in the settings.

    Ihave the same Chrocodile, and I found that in the book as well. We use a frequency at 320, but that depends on your product.

    Mihael
  • This is a very good question. I had requested on the other site to make a white light sensor section of our forums which I am told is on the way. Anyways to answer your question MihaelR rick did for the most part. I unlike yourself though have spent hours testing and tinkering and changing lens and registry settings, controller settings ect. There were so many things I discovered that were failed to be relayed or told to me upon acquiring this new tool. Even things that aren't explained in the manual because not many people at all know the exact interaction between this new technology and PC-DMIS. I as well have an Optiv but it is an older controller. I also have a CHRocodile S.

    Here are a few starting tips:
    -If you have a older controller like myself this controller can ONLY handle data collection speeds up to 250HZ. Running anything over 320hz is almost pointless now. This was very disappointing to find out AFTER the purchase for a controller that can handle up to 2k.
    -Never cancel in the middle of a scan or a long scan unless absolutely needed, the machine will continue to scan until it is complete. It won't stop unless e-stop or pc-dmis has been closed. So if you choose a long scan or mess up a speed setting you will be waiting for some time unless you do a hard shutdown.
    -You can "flood" points to the machine controller with WLS controller causing false data as well. Try to find out what your machine controller limits are. Hopefully you have a newer one.

    -If you change lens like I do, you need to check a few things:
    ----You will need a completely new calibration routine if running for more than one probe( I run 3 Vision, TTP, WLS). I had to write my own.
    ----You will need to change the indexing in the registry to make pc-dmis alk to the controller so it knows you have a new working range. (600µm, 3mm, ect.) HM has not yet coded this in to make the change through pc-dmis itself. Possibly with new software/updates they did per some of my help.
    ----I keep the Quality Threshold anywhere from 10 to 25 out of habit. Default is 25.


    There is a lot more I just can't think of at the moment. Best of luck using the WLS. It has been very fun learning to use it despite the headaches. I have uncovered new applications using it as well and it has helped increase my programming and machine knowledge immensely.