I don't know how you're going to get something like this to work. You say you're building your own mux circuit. How is the software supposed to know about the mux and it's timimg? What's going to indicate that a certain channel in your mux is active and for how long? The 6024 muxes 16 inputs into a single DAC and you get an array out with separate rows and columns representing channels and samples but there's a tight integration between the board's hardware, firmware, and NI-DAQ. You would have to provide some of the same sort of integration in order to separate the four different signals. Even if all of this is possible, by the time you're done, it would have been cheaper just to buy an additional 3 5B modules and dedicating each to a 6024 channel.
