Real time data processing

[Gautam Dee]

Hi everyone

I am working with a data acquisition project using a cRIO 9014 controller and NI 9239 analog card. Right now i am streaming the data to my laptop and trying to process it (find the RMS value of each channel and display it as a bar). I want to decrease the bandwidth for communication so instead of geting the data into my laptop, I want it to be processed in the cRIO's controller and just send back the RMS value of each channel.

Right now I am using a FPGA vi to read the data(one single DMA to group the data from 4 channels), a tcp connection vi, and a host vi(to separate the channel data and find time average and RMS value.) to display.  Can anyone give me an idea of how I can process everything in the rio controller and just get back the rms values of each channels.

Thanks

Tamanna 

[DanRichards]

Hi Tamanna,

Have you tried getting the RMS values within the RT VI and then writing those values to a network-published shared variable hosted on the RT controller? Then you could read those variables from the RT target to your host as needed.

Let me know if this helps.

[Gautam Dee]

Hi Dan

I have a couple of questions, I am new to fpga programming.

1. Usually as far as my understanding goes, the data from the fpga vi(which is written on the chip in the controller) is written into a fifo through a DMA channel and then read from the fifo in the host vi. Can i download a vi onto the chip which can process the data and give me the final output of processing? what I mean to say is that, can I play around with the data in my fpga vi without writting it into a fifo ?

2. Is it the only option, that I use shared network varaibles to talk to the microcontroller remotely ?

Thanks

Tamanna 

[DanRichards]

Hi Tamanna,

1. Yes, you can play around with the data in the FPGA VI. The ideal use of the FPGA chip is to run feedback loop control headlessly and only get important data back to the RT controller for logging or transmission to the UI.

2. You can also communicate by TCP/IP. I'd check out this article (http://zone.ni.com/devzone/cda/tut/p/id/4905) for more information.

Let me know how things are going and if you hit any snags. 🙂