I'm not exactly sure what you mean by configuring the voltage DAQ system of 400 channels. Do you already have the DAQ hardware, and you don't know how to set it up? Or are you asking what you would need to perform such an operation?
If it's the latter, your best bet is to use one PCI-6033 card (to put in your computer) with two SCXI-1001 signal conditioning chassis. You can then use 13 SCXI-1100 analog input cards, which have 32 channels each, and are differential isolated inputs. These can be scanned easily at 10 times per second.
Hopefully that pointed you in the right direction.
