Uh, why? Embedded systems normally try to be as efficient as possible, so using only 1 byte instead of 2... This is Java not C++. An integer in Java is 32 bit. The problem is that I need that for Windows, Mac and Linux and I definitively do not want to implement this for 3 platforms on a driver level. I am wondering how NI did implement that, do you think they did on this level or is there a better library than LibUsb?!