QUOTE(gottfried @ Oct 12 2007, 05:22 PM)
The Neville_D's answer is the one to go with - sample fast and resample in software. You need to think about what method you want to use to do the resampling, as there are several, and it really depends on the applicaiton. For example, if I wanted to acquire a slow signal at x Hz and then a fast one at 3x Hz, I acquire in hardware at 3 x Hz. Then, how do you get your x Hz signal? You can decimate the 3 x Hz signal to get the first value, the second value, the third value, a mean of all three values, the highest value, the lowest value, etc. You also may need to think about syncronisation - do you need to justify which data point that you're going to select? etc...