9/1/2015 1:54 PM | |
Posts: 5225 Rating:
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>> This text was late << Jeff Casagrande seems to be taking the right road.. getting the source stable. So ignore what follows for now. Hi Bruno,
Measurement is not linear? That is a tough one. Normally when this occur with me, it means the "platform" is too big / load cell is damaged / working on the edges of the load cell range. Your situation is clear now.. use the filtering action after linearization. The filter can work in engineering units (kg). Just know the "zone" setting should be in the same units - as mentioned before.
It very much depends on how quick the output should react. Begin with 0.95 (95%) and work your way lower... yes - by experimentation or by educated guess.
Liquid? No wonder you are having problems. Do consider the mechanical motions ("vibration") that is involved when handling the liquid. I do not fully understand you description. The ripple is 200g? What is the smallest increment that the PLC can measure? (10-bit / 12-bit / 13-bit) 200 / 5000 = 0.04 or 4% ripple... that sounds high. If this is the case then I wonder how the mechanical design looks like and doubt that the algorithm I give you will be helpful. (I don't like it being blind for the system's design - it makes me give bad advise.) If you make #Zone big (1kg) - the filter will be used exclusively but the reaction time may be influenced. Maybe start big and work your way smaller. ----------- That is all I can do for you now - good luck! |
Last edited by: William_B at: 9/1/2015 1:59:42 PMAdd introduction note |
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9/1/2015 2:12 PM | |
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I have been in this situation so many times, trying to make software solve a hardware issue. The first thing to do is to understand the problem you are trying to solve. |
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9/3/2015 7:03 PM | |
Posts: 70 Rating:
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Hi, My load cell is fixed in the balance base through a screw (just like it came). But, if is out of the alignment, the variation will be so great as mine? How large should be the capacitor in your opinion? Sorry for my silly questions. I used this circuit because I needed a signal from 0 to 10V, and was the cheapiest. The all cirtuit is design in the attachment file. Thank you for all the help AttachmentCircuits.rar (287 Downloads) |
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