Analyze oscillation over time

[aham312]

New user, and first person in my company to use labview.

I've been learning labview over the course of the last few weeks for use in one specific project. I have a good understanding of the basics of the program, but I am nowhere close to doing what I want to do, so I'm hoping for some guidance. I'll do my best to explain what I'm trying to do, and hopefully someone can point me in the rigt direction.

I'm running a lifetime test system which returns an oscillating system continuously over several weeks/ several million cycles. The goal with labview is to analyze how the oscillation changes (decreases in speed and/or magnitude) over time. I am able to successfully see the signal on a waveform graph, but the real goal here is to quantify the changes in the signal over time. I want to: 1.)Save an image of the graph at regular intervals (i.e. every few hours); 2.) take an average maximum magnitude reading at regular intervals (in other words, average the maximum values of 100 or so oscillations). 3.) Take an average time (from minimum to maximum) reading at regular intervals, and 4.) Plot changes in average maximum and average time over the course of the entire test.

The utimate goal is to analyze detioration of a device and determine when significant detioration starts to occur. I assume none of this will be especially complicated, I just want to know what specific features of labview I should learn about in order to make this happen. Any direction would be much appreciated.

Thanks.

[Bob_Schor]

I can tell you what got me "up to speed" fairly quickly.  When I started learning LabVIEW, I was already a pretty experienced programmer (Fortran, Pascal, Matlab, PostScript, machine language), but had never worked with a language like LabVIEW.  I bought two books -- Jim Kring's "LabVIEW for Everyone" (which taught me LabVIEW) and Peter Blume's "The LabVIEW Style Book", which taught me LabVIEW Style.  I read both books cover-to-cover, but read the Style Book three or four times over my first year learning LabVIEW, and tried to apply its principles in my LabVIEW Development.

Bob Schor

[NIquist]

Your application is exactly the kind of thing that LabVIEW excels at.    Basically, you want to code a data logger that includes some simple wavefor analysis.  I would suggest you just save the waveforms themselves in the TDMS format.  That way you can open them back up with LabVIEW (or using the free MS Excel plug-in) and view, analyze or print your data at your convenience.

The general choice of overall architecture for this type of app is the ubiquitous STATE MACHINE.  Are you familiar with it?  There is a template to get you started but most of us expand on it with queue-driven states and a user interface loop so yoiu can modify parameters of the test on-the-fly.

https://www.ni.com/en/support/documentation/supplemental/16/simple-state-machine-template-documentat...

http://www.notatamelion.com/2015/02/23/building-a-proper-labview-state-machine-design-pattern-pt-1/   <<<  Mike Porter's excellent blog on the subject.

You will also need some skills with the DAQmx functions.  There are many good examples included with LabVIEW:  Help > Find Examples...  Hardware I/O > DAQmx > Analog Input.  

https://www.ni.com/en/support/documentation/supplemental/06/getting-started-with-ni-daqmx--main-page...

https://www.ni.com/en/support/documentation/supplemental/06/learn-10-functions-in-ni-daqmx-and-handl...

Once you get started, post your code and give us more specifics about the hardware you're testing and we'll be able to help you work through this.