03-11-2010 04:37 PM
Hi
Today I performed a little experiment using cRIO and waveform generator in the lab. I set a sine signal on waveform generator with amplitude 5v and 1khz frequency. I connected it to analogue input module on cRIO analogue connected, configured and running in scan mode. I didn't get sine signal. I got a dirty signal randomly flowing everywhere.
I connected power supply which could be varied from 0 to 35 volt using it as an alternative to analogue sensor for simulation in lab. That worked pretty good. (What I was setting, I was getting on waveform chart). I wonder what's the problem in first case.
I also want to simulate some digital signals and use these signals to design a vi which could be an indication of continuously varying property e.g using digital sensor to measure rpm (which varies as speed vary) and using rpm to design a vi which show speed on waveform chart. I wonder what could I use as a digital signal simulator whose frequency could be varied.
Many thanks for patience
Cheers
03-12-2010
12:05 AM
- last edited on
03-19-2024
10:31 AM
by
Content Cleaner
Good Evening kwaris,
Depending on your hardware and input signal, you may have issues sampling at the needed (Nyquist) frequency to get a good representation of your signal.
NI Scan Engine Performance Benchmarks
https://www.ni.com/en/support/documentation/supplemental/08/ni-scan-engine-performance.html
A drastically undersampled sine wave can look like a dirty signal randomly flowing everywhere.
I would expect the second test that you ran to work rather well since it sounds like that power supply was outputting a DC (constant until you changed it) voltage.
If you would like to sample faster than you are currently capable of (and to take full advantage of the hardware you purchased) you may want to consider programming your cRIO in FPGA Interface mode.
What Is LabVIEW FPGA?
NI LabVIEW FPGA Module
https://www.ni.com/en-us/shop/product/labview-fpga-module.html
LabVIEW FPGA Module Training
https://learn.ni.com/learn/article/getting-started-with-fpga
Be careful with the 35V supply...very few C-Series modules can handle that voltage.