LabVIEW
Fpga Signal Processing (Analog output)
Hi,
I have obtained some chaos signal reasults from equations and I want get same results with labview fpga on oscilloscope.
My question is ; Do I have to programme in FPGA VI from scratch or there is a possible way to implement to FPGA the programme that I already did ?
Hi tahatas,
@tahatas23 wrote:
My question is ; Do I have to programme in FPGA VI from scratch or there is a possible way to implement to FPGA the programme that I already did ?
Well the FPGA does not support any UI: so your current VI with several charts/graphs and even a 3DGraph doesn't make sense to run on a FPGA. LabVIEW FPGA also does not support DBL datatypes…
Did you do any basic training on programming LabVIEW FPGA? There are quite some (subtle) differences between LabVIEW on a Windows computer and LabVIEW on a fixed-sized FPGA!
@GerdW wrote:
LabVIEW FPGA also does not support DBL datatypes…
Actually it does nowadays. But!!!!!!! You should not use it if you can avoid it! And use of it in arrays is certainly going to blow up your compile very quickly since you won't have enough fabric resources on even the larger FPGA circuits.
Floating point arithmetic is very inefficient to implement in hardware! It doesn't generally work inside timed loops (since floating point requires variable sized looping for many operations).
So no the original design is certainly not directly portable to FPGA. The most obvious things are the graph front panel elements which you don't have on FPGA and you will indeed most likely have to look into using fixed point floating point values which likely are good enough for your purpose. And you will need to use probably FIFOs instead of the Stripchart graph accumulator VIs and then read the FIFO in your real-time app and do the graphing there, or probably relay the data from there to your host computer to do the visualization.
All in all not just a simple recompile for sure. You usually end up with three different software "applications": the FPGA compile, the real-time controller and a desktop host application that does the visualization.
Is it worth the effort? You will need to decide. Why do you want to do this in FPGA at all?
Hi Rolf,
@rolfk wrote:
@GerdW wrote:
LabVIEW FPGA also does not support DBL datatypes…
Actually it does nowadays.
On NI's website I only find the LV2018 help, which states "only SGL for FPGA".
You can download the LV2020 help, which states "no DBL or EXT for FPGA"…
Haven't found LV2021 help or downloaded/installed LV2021 yet…
Yoú're right only SGL support. But that is still very inefficient to use on FPGA and definitely not for arrays in any ways. You want to go FXP with a suitable format for the numeric range needed. As the actual feedback control seems to be scalar in the program this seems doable. The strip chart accumulator however needs to be replaced with FIFOs and the actual array accumulation needs to be done on the real-time side.
My questions in the previous post still apply.
