LabVIEW can only handle unsigned integers up to 32 bits. Therefore, you need to split the 64 bit word into a 32 bit hi word and a 32 bit lo word. For the 24 bit word, use a 32 bit unsigned integer and ignore the top 8 bits or split it into an 8 bit hi word and a 16 bit lo word.
If you attach a vi explaining exactly what you are trying to do, I may be able to help more. Dave.
