Your AI and AO run a vastly different rates, thus you should place them in seperate loops. You should also pull the timing and start VIs before the loop.
(Currently, your error wire gets reset with each iteration, you might want to keep the errors in shift registers)
Thanks to tell me.But,could you please to tell me how to modify them?How do I make AI and AO synchronization?
You might consider looking at some of the synchronization examples which can be found under Help » Find Examples » Hardware Input and Output » DAQmx » Synchronization. I believe the Multi-Function-Synch AI-AO example would be a great illustration of what you are trying to achieve. This example uses both AI and AO and it is also synchronized using triggers. Finally, the data read in is outputted to a waveform chart similar to what you are having difficulty with.
I really refer to these examples.I changed my vi.But,I couldn't see the plot of the chart and detected frequency.Could you tell me what's the problem with it?