acqusition of the data via myrio

[as2717@sussex.ac.uk]

hello, i have encountered some problems on the way of plotting psd spectrum density in matlab , as a source i used the excel file with data from labview. Time and amplitude. 

The data from the graph is wrong, it shows some random freq on the plot, IDK whats wrong.

Im kind of new here with dealing FPGA labview MyRio.

and the thing is im exporting data from the Myrio 1900 ai0 connectors graph (output of opamp) to  the excel file. but that excel file contains wrong data. i mean just looking at the graph chart i can see difference with scope.( i checked the output before with oscilloscope)

do smn know how to use it so it will work eventually? Because i think I need to use FIFO or smth advanced . pls i need help.  

ps dont look at the empty graphs i didnt run anything yet. PLS HELP. I AM USING MSP connector. with 1 sample rate i think. 

[GerdW]

Hi as,

no need to start a new thread for the same topic. Keep things (and discussion) in one place!

Mind to share some code? We cannot debug/edit/run images in LabVIEW!

[as2717@sussex.ac.uk]

sinewavegen file in fpga. 

[GerdW]

Hi as,

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as2717@sussex.ac.uk wrote:

sinewavegen file in fpga. 

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There is no "sinewavegen" file in the archive. (Apart from that bitfile, which is just "compiled code".)

Where did you place your VI?

Why is the project still "untitled"?

[as2717@sussex.ac.uk]

sorryyyy

[Bob_Schor]

There are so many "moving parts" to your situation that I find it difficult to understand (without seeing all of the relevant LabVIEW code) where the problem lies.  Here are the parts I know:

1. You are sampling analog data at some rate using a myRIO.  Please (re-)state clearly the sampling rate and type of sampling (finite vs continuous, # of channels, how many samples acquired at a time).
2. You appear to be acquiring these samples using code written for the myRIO's FPGA.  How are you getting these values to the processor inside the myRIO running NI Linux LabVIEW Real-Time?
3. You mentioned saving the sampled data in an Excel format.  Where is this file generated?  I'm assuming it is on the PC running LabVIEW and "hosting" the LabVIEW Real-Time Project whose Real-Time code is described in Items 1 and 2, but this isn't clear.

To provide you with meaningful help, we really need to see the entire Project, preferably saved for LabVIEW 2019 or 2021, both of which have myRIO Software Toolkits that will support the myRIO and integrate with LabVIEW Real-Time.  

Bob Schor

[as2717@sussex.ac.uk]

1.sampling rate of sine wave generation loop is 1000 tick *25ns continuous

the acquiring channel sample rate didnt define so, it is ordinary 500ks ? yes? for Ai0 MSP connection.

 number of channels are 3,  sine wave input, output of sensors, and subtraction each other. i think that subtraction also need some adjustment. idk. how to do smpl rate adjustemnt between them. 

2. im using typical labview fpga myrio project.

3. excel file is extracted simply  from graph of input ai0. 

[Bob_Schor]

Regrettably, I'm at a meeting far away from my own myRIO devices.  Something seems wrong with your sine-wave generator, but I can't put my finger on it without poking around a bit, perhaps generating a very slow sinusoid and using Bob-friendly Time Units (like ms instead of Ticks).

Back to Gerd ...

Bob Schor

[GerdW]

Hi as,

charts doesn't make sense in a FPGA VI as the FPGA doesn't provide any UI capabilities…

Use FIFO(s) to transfer data to the RT host!

[as2717@sussex.ac.uk]

ok ill try, but its too much work, are there any other method than using dma fifo?