02-17-2010 06:56 PM
I attached an image showing the spikes I am seeing with triangle waveforms. Mike_Combo.vi is the program I 
use.
Analog Input is on the left and Analog Output is on the right. 
Follow this 
setup to see the noise.
Input Config:
Rate (Hz): 
200000
Samples to Read: 20000
File path: savefile.bin (labview 
binary)
input terminal: Differential
Byte order: I use "native" so I can 
open in MATLAB
Output Config:
Phase: 90
Sampling Info 1
Fs: 
100k
#s: 1000
Sampling Info 2
Fs: 100k
#s: 0
Thanks for any help.
02-18-2010 03:40 AM
What type of hardware are you using?
Are the spikes constant in frequence, signal amplitude or signal position?
Some spikes look like a zero crossing distortion in the output amplifier, however without playing with Uss and freq and samplerates (in and output!) it's hard to tell 😉
In a first reflex I try chokes against spikes
Upps, didn't know that this pic is that big , sorry.
02-18-2010 07:56 AM
Hi Henrik,
Thanks for taking a look! The spikes seem to occur at ~ 0mV, 315mV, 630mV, and 950mV for the waveform I am using. When I change the frequency of EITHER the input or the output this does not change. What I am trying today is changing the frequency of the triangle waveform to see if that effects the location of the spikes, however, my instinct is that it will not. My boss suggested it may be a problem with the D/A conversion tripping up.
Did you try to reproduce the result by any chance? I have used 3 different cards on 2 different computers with the same results.
Thanks,
Mike
02-19-2010 06:26 AM
What hardware are you using?