How are you looking for the pinouts? Look in the manual or in MAX, right click on the device and select 'Device Pinouts'. Ai0 is 68, ai1 is 33, ai2 is 65. The pins don't change. What changes is the pins to use if acquiring differential or single ended. For example, if you acquire a differential signal with ai0, you use pins 68 (ai0) and 34 (ai8).