The easiest way to do this is to use software to calculate the complement of the data that comes in. The board will read U16, and then you can use either specific functions that calculate the complement (depending on what software you are using), or pass the data through a function that you have or create that will convert the data for you.
Hope this helps. If you have further questions or concerns, please include a little more information about what you are trying to do (more than one sentence please). Thanks, and have a great day.
The NI 6542 is a 32 channel device and you can configure each channel as input or output in software. You can configure all your channels to be input if you wanted to. That being said, could you please be a little more specific on your requirements? Is the data that you are reading going to be hardware clocked? Will you be reading this in continuously or for a short period of time? Is this16 bits of serial or parallel data?
The logic to determine true/complement data would be implemented in software using the NI 6542. You can use software such as LV SignalExpress for quick acquisition and analysis or even LabVIEW or a text based programming language for greater control.
Please refer to this article for more detials on how to use these instruments.