Thanks for your post. I have a couple of ideas and questions so I can figure out why your not getting an output of 5V.
What type of load (if any) do you have connected to the digital
output lines and the +5V line? If the load draws too much current from
either/any of the lines then the output logic level will start to drop
below 5V. Are you using the device in push-pull (3.3V) or open collector (5V)
mode? Also, do you have the load connected when the device is powered up?
Try measuring your +5 V pin on your analog input line. What voltage do you read out?
Many thanks for using the NI forums and I look forward to your reply.