Thanks for posting on the NI Forums! Dennis is right, you will use the AI Start function to set your acquisition rate. If you are just starting out I would build off of an example. Go to the NI Example Finder by clicking on Help?Find Examples. Browse by Directory Structure and navigate to daq»anlogin»anlogin.llb»Cont Acq&Chart (buffered).vi.
That being said, if you are a new user, I would strongly suggest using NI-DAQmx instead of Traditional DAQ. Your question is one of many good reasons to use NI-DAQmx. It is a lot more straightforward and you can build applications quicker. There is a DAQmx Timing function where you configure your sample rate, and anything associated with timing (such as sample mode, clock source, etc.). Go to the NI Example Finder and Browse by Task. Browse to Hardware Input and Output»DAQmx»Analog Measurements»Voltage»Cont Acq&Graph Voltage ? Int Clk.vi. <a href="http://zone.ni.com/devzone/cda/tut/p/id/5434" target="_blank"> Getting Started with NI-DAQmx</a>