Hey Easen,
1.) Are you using NI-DAQ 7.4? The DAQmx Team added support adding an SCB-68 to each of your connectors. You can also configure each connector seperately.
2.) I assume that when you say "ports", you are refering to the analog channels and not the digital channels. In which case, I assume that the problem is that you are trying to run two different analog input tasks on the same board. This is not possbile because all of the analog lines are viewed as a single resource. However, you can configure the analog lines in different create channel VIs and string them together, in the same task. Then you will have to sort the reading out, as they will be based on two different scales.
-Let me know if you have any further questions.
-Justin