The hardware you need depends on the specific detail of your system (number of measurment channels,number of control channels, scan rate etc.). I am currently building a measurment & control system for a big electrical system, the system consists of 48 AI, 14 AO and 40 DIO. so I am using the SCXI system which is a good solution for systems with a lot of channels.another good solution is field point which gives you the power of distributing you measurments on a large area. the probem with both these systems is that they lack AO hardware with large number of channels, if you need alot of AO channels I advise you to look at the PCI6704. I advise you to look in the ni site at "products & services" the have all the information about all the ni hardware plus there are wiza
rds that help you choose the proper hardware.
