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Does dithering impair performance of MIO boards?

I read "For high-speed applications that do not involve averaging or spectral analysis, you may want to disable dithering to reduce noise."

What about high-speed applications that do involve averaging? Where does high-speed start?

Also: Can I dither a particular AI channel? It seems that enabling dirthering would dither all channels. Is that correct? Do I have to enable dithering on both of my synchronized DAQ-boards?
I am using two AT-MIO 16E-1.

Any help is welcome!

Thanks, Martin
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Martin,
The sentence on dithering is not worded as well as it should be. You only want to average a DC signal or a very slow AC signal. Consider sampling an AC signal at 1 MSPS and averaging 100 pts. That is effectively 10 KSPS, so according to Nyquist, that's a 5 kHz signal. If you want a decent representation of the wave (10 Pts/cycle), the frequency is effectively 500 Hz. Thus, high speed signals and averaging really don't make sence being talked about together.

You can only turn dithering on or off for the entire board, and yes it would be best to enable dithering on both card.

Nick Wilson
National Intruments
www.ni.com/ask
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