cRIO 9076 + NI 9234 issue

[foxman]

Hi guys,

There is a task to acquire data from analog sensors using cRIO 9076 + NI 9234. The task is solved with FPGA and FIFO buffer (code segment is attached). Sample rate is 200 Hz. I disconnected all sensors. During debug I have an issue of appearing "bursts/needles" in the data. I was not able to find out a reason for it. What is typical, when I start topLevel VI and it receives the first package, the "needle" immediately occurs in the data (see graph in the upper left corner) and this is repeated in 8 out of 10 cases. The needles appear without any specific periodicity and affect all channels at once. Has anyone come across this behavior or maybe know what it might be connected with?

P.S.  MasterTimebaseSource parameter is set to Mod1 for all modules.

I attach an example of real buffers for viewing in VI.

 

data.vi