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6/10/2012 2:52 PM  
Posts: 2 Rating: (0) 
Hi all, I need help to detect the input signal from analog input and outputs on digit output if it is SIN or COSINE. Any starting ideas or links or sample programs? Thanks, 
6/10/2012 3:43 PM  
Posts: 378 Rating: (70) 
Seems interesting, I am not sure if it is possible to make calculations like sin or sin1 on LOGO, but you can try by compairing samples. Inorder to do this you need to find a way to know: 1. Your maximum and minimum analog values. 2. The frequency or wave length of your analog signal. Then try this dumb way, For example let say your analog value is in the range of +5.0V to 5.0V, and the frequency is 1Hz. Therefore the expected values of the analog input values will be: t(sec) Values(V) 0 0.00 0.125 3.54 0.25 5.00 0.375 3.54 0.5 0.00 0.625 3.54 0.75 5.00 0.875 3.54 1 0.00 As you can see the above if the first two consecutive values are 0.00v , 3.54v and then the next value will be 5.00v .....and so on. Note that on this example I take 9 samples and may not be 100% sin wave. Inorder to increase the acuracy you need to increase the sample's interval. Now I am sure you can write this steps in LOGO functions and or you can creat your own UDF files. Check this link may be it has some usefull starting ideas for you /tf/WW/en/Posts/47540 Good Luck! 
Last edited by: desmul24 at: 7/7/2013 8:27 PM 

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