Hi,
the sampling rate of an A/D board is not constant, what is fixed is the maximum sampling rate, this is a feature of the A/D converter.
After this, you have two options:
1- A/D board with simultaneous sampling (NI S-series):
here the sampling rate is the same as scan rate this because you have as many A/D converters as # of inputs.
2- A/D board with multiplexed inputs (NI E-series and others): here you have only one A/D converter, the channel selected are multiplexed sequentially to its input.
The Scan rate you set is the number of samples/second you want each channel to be converted, actually it is the sampling rate for each channel. If you are doing a multi-channel acquisition the sampling rate of the A/D converter is equal at the scan rate multiplie
d the number of channels. Therefore always keep in mind that the maximum scan rate (sampling rate per channel) you can set is maximum sampling rate/number of channels.
I hope I've been clear enough,
Alberto
