samples of a sinusoid signal acquired with crio 9039 are not correctly aligned

[unikin_poly]

Good morning, everyone,
I am currently designing a real-time measurement software based on the crio 9039.
There is an FPGA part where I am acquiring the signal one sample at a time that I read from the rt processor using a reference to the FPGA and the Read/Write function to a command.
However, when I acquire a sinusoid I find that there are samples that are not perfectly aligned with the others.
I thought it was a chassis grounding problem but it's not that.

Can someone help me?

A capture of samples that aren't aligned with other

[AndyClegg · Accepted solution]

Make sure you fully undertand the method of data transfer you are using, including the limitations, and make sure you are using something that can give rise to missing data which is what it looks like. There are plenty of examples in LabVIEW for you to learn about the different methods - for example, DMA FIFO (http://zone.ni.com/reference/en-XX/help/371599P-01/lvfpgaconcepts/fpga_dma_how_it_works/)