David, you could check this example. It generates a variable frequency and duty cycle pulse train on a counter's output.
http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B45EACE3E9F156A4E034080020E74861&p_node=DZ52328&p_source=External If you want to synchronize this output with an analog input capture (one point), you can wire the output of the counter to the appropiate input (AI Convert or AI Scan Start), and use one of the External Clock examples to acquire the analog sample(s). Hope this helps. Let me know if you need further help,
