Here i was using a asynchronous call and wait function to acquire a voltage signal from daq 6211 in a subvi and main vi will display the results but when i need to control a sampling rate how can i command a signal from main to subvi, here i have attached a vi to analyse here.
for transfering data a queue can be used. If you want to change the sample rate the taks must be stopped and fresh configured and started. What you can do is to set the highest sample rate for the acquisiton and make a resampling, if you want to get less data. In your example a finite acquisition is in use.