There are no examples to show specifically showing getting different streams with different decimation ratios. It is possible, but this use case has never been done.
The NI 5640R VIs only supports a few of the possible permutations available in the ADC. You can modify the ni5640R ADC Configure DDC.vi to configure the ADC for more advanced use cases.
The main use case that is supported with the NI 5640R in configuring the channels is to vary the bandwidth of the acquired signal. Each channel has a bank of filters which are used to filter the signal and the aliases produced by the DDC itself. However, as you increase your bandwidth, the bank of filters is not big enough (you would need more taps in your filters to be able to filter your signal adequately). So, in that case, what you can do is combine the filters of two or more channels to filter a single stream. And that's what the "ADC configure DDC VI" does: depending on the requested bandwidth it programs the needed number of channels to filter a single stream. So, you can't use that VI to get multiple streams. You could look at it to see how it programs the channels and then make your own. Even after doing this there will be one more challenge. On the FPGA VI, in all of our examples we only get the I and Q values from the ADC I/O Node. However, if you have multiple streams coming out from the same ADC you also need to look at the "Channel" I/O Node to figure out to which stream does the sample belongs.
The current version of NI 5640R only supports one port, Port A, in Interleaved I/Q mode.
You can find more information on the channels, the ports and the Interleaved I/Q Mode in the Analog Devices AD 6654 specification document.
