How create a continuous XY Oscilloscope?

[charles_S]

No i am searching to do a continuous mode and i understand to plot 10 000 points can be useless but my problem is not when i plot, is when i try to shift my datas.

I want to use my oscilloscope for a long time acquisition and I don't want to declare a big array so i am searching a way when my array is full.

And it's to display my X and Y datas that i want. So the Stripchart seems to me a bad way.

[RobertoBozzolo · Accepted solution]

Hi charles_S, have you made some further advance on this matter?

I was puzzled about the overhead introduced by shifting data so I realized a simple app that generates 20 arrays x 10000 samples of random data and plots them on screen: on my machine (Win7 Pro + CVI2012SP1 on Intel Core i3 CPU) I cannot notice a significant increase in elapsed time between non-shifting and shifting part of the process; I tested various method for shifting data with no substantial difference as you already have noted. There are other factors that can improve system performances and I added options to test some of them.

I understand that my example is way much simpler than your app, but since my results are significantly different from yours you may want to check the codes for difference and maybe you can find some tip to speed up your process.

[RobertoBozzolo]

Another fact that comes to my mind is that the graph control never reuses the plot handles even if you delete the plots. That is, in your case the plot handle will continue increasing indefinitely.

Now, I don't know if the graph control has some limitation in the number of plots and plot handles that can retain, but consider that in your case (26 plots per graph at 2Hz) you are plotting ~187000 plots  per hour 

I suggest that at least you perform a several-hour test to be be sure that no problem arises as the plot handle increases in value.

[charles_S]

Thank's Roberto!

I found my problem, is that I will search my datas one by one in my 500 points acquired and i shift my array each time that I will search them.

I change it to shift after that i put all my 500 points on my plot array.

i know was an evident problem but i got stuck on the fonction Shift() and i didn't see my problem.

Thank you very much for your example and for your answers

[RobertoBozzolo]

I'm happy to have helped you!