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Thread: Working out PPS

  1. #1
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    Default Working out PPS

    Can anyone tell me of a way to find out the PPS output of my PM25 control desk?

    When I bought the desk I was told that it was set to 18k PPS and is not adjustable. I would like to confirm this is correct as I want to make sure that my ScanPro20's are being tuned to the right speed.

    Carl

  2. #2
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    Default

    You'd probably need an oscilloscope to be sure.

    Adam

  3. #3
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    PPS refers to how many PPS you scanners can draw the ILDA Test pattern..
    The ILDA pattern is designed to be very hard to scan. It uses long swings and a complex array of designs to basically torture test your scanners into submission.

    a 20kpps scanner could probably draw a circle at 40kpps (circle is a simple easy shape for a scanner)

    so your question is slightly vague.. what do you actualy want to know about scanners?

  4. #4
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    Keeperx

    My knowledge of how to tune scanners is very limited but do have some basic understanding that the ILDA TP is complex and designed to drive scanners quite hard at there rated speed.

    WRT the PPS speed of the output from my desk if is as mentioned above of 18k PPs would scan a simple pattern with say only 10 points then the desk would scan that pattern 1800 times a second and a more complex pattern with say 100 points, then the desk would scan that pattern 180 times a second.

    My question was to find a way to clarify the PPS speed of my desk and was thinking that only a scope as Adam has suggested would be the only way. Something I don't own. The next time I get to see Rob Stanwax, maybe he could help with this.

    Carl

  5. #5
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    What is your goal? To tune your scanners to whatever speed the board puts out? I think I would just tune them to 20K.

  6. #6
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    Quote Originally Posted by Carl B View Post
    The next time I get to see Rob Stanwax, maybe he could help with this.

    Carl
    Maybe I could - though I guess I wont be doing much scanner tuning this weekend

    Rob
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  7. #7
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    Quote Originally Posted by carmangary View Post
    What is your goal? To tune your scanners to whatever speed the board puts out? I think I would just tune them to 20K.
    Sorry to split hairs here.. but when you say tune them to 20k, what are you talking about??

    20kpps is 20-khz or 20,000 instructions a second

    AKA 20,000 little sine waves flying thru the the galvos every second

    so as i said.. a CIRCLE could be scanned much faster than the ILDA pattern because its a very gentle curve that repeats and the galvo's just hum along..

    the ILDA pattern is harder so you have to to lower the Khz to compensate (less instructions per second).

    so 20kpps doing what?

  8. #8
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    and FYI tuning scanpro 20s to 20kkpps(ilda) is fine if your gonna run them at 18kpps(ilda)

    you do not tune TO a specific speed, you tune to a MAXspeed.. anything below the max speed is gravy

  9. #9
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    I'm talking about tuning to 20K with the ILDA test pattern. It is implied that when talking about tuning that the ILDA test pattern will be used.

  10. #10
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    Quote Originally Posted by carmangary View Post
    I'm talking about tuning to 20K with the ILDA test pattern. It is implied that when talking about tuning that the ILDA test pattern will be used.
    I know YOU knew what you meant.. i was playing devils advocate so i we could help Carl better understand what he was actually doing

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