05-04-2010 06:06 PM
The data used in my project is acceleration signals acquired from different location. Then I use following steps to find the peak: Vibration Level (Use Single Integration function to convert the signal into velocity) - Power Spectrum - Peak Search. Using these steps can only find the max peak in only one block. So I need to go through all the max peaks in every blocks and find the max one. Is there any way to find the max peak in a whole playback data? I have changed the block size in Tab (playback options), but that doesn't work.
Thanks advance,
Du
05-05-2010 02:51 PM
Du,
My understanding is that you're trying to search a large dataset for an overall maximum amplitude. Here's how I would go about that:
As you run through the data, store the magnitude of the highest peak found in each section. Compare subsequent local maxima to the stored maximum value, and if they are greater, rewrite the new maximum to the storage space. After you get through all your data, whatever value is stored should be the highest in all the subsections of the data. I might use a shift register to store the value. I hope this helps!
05-06-2010 10:49 AM
I tried this method, but need too much time to conduct this process.
Anyway, thanks a lot.
Du
05-07-2010 04:07 PM
The way I do it is insert a Statistics step somewhere after your DaqMX Acquire step. Within this Statistics step you have the option to export Min, Max, or RMS values for the selected channels.
Ive been doing some recent testing involving heatsoaking large plastic containers while measuring clamp loads on the straps, so it's a temperature vs. load (clamp load washers). The min/max temperature and max loads at max temps are the values of interest.
Hope that helps