Hi Jon,
thers is an example in Lv for digital triggering an analog acquisition.
You can find it at:
\EXAMPLES\DAQ\ANLOGIN\ANLOGIN.LLB\ContAcq& Graph(buffered)D-Trig.vi
See the vi help that gives a complete description.
For your task you should add a simply digital output routine ( there are many examples) and make the proper connections.
Good luck,
Alberto