As far as I can tell your program is right. This is evidenced by your analog output looking similar in a scope to the chart. That leaves me with hardware problems. Do you have a spare 9215 you can swap in? You've tried each of AI0-3? Try a different input source like maybe a battery or a power supply. You are following the connection instructions on page 14-18 right?: http://www.ni.com/pdf/manuals/373779g.pdf Do you have the BNC version or the spring terminal version?