In the new DAQmx API digital inputs and digital outputs are accessed via Tasks in the same way as analog inputs and outputs.
So you would first Create a new task, then configure the task (in your case configuring which lines or ports you want to read from/write to) eventually configure the timing, and afterwards you can read/write the task. You can use the DQmx-Assistant, too.
Because you have not named your Development Environment, I could not include concrete function or VI names.
Check out hte example library of the developer zone, you will find examples for Digitla I/O with DAQmx there.
http://search.ni.com/nisearch/nisearchservlet?nistype=default&ddown=3&filter=%2Btaxonomy%3A%22Example+Code%22&q=Daqmx+Digital