Hi Peter,
Here is a knowledge base article that will help explain what is going on with your code.
Why does an SCXI Single Scan Take Longer in Traditional NI-DAQ than in Ni-DAQmx?It's true that you're not doing a single scan, but the vi that you are using sets up the channel on each iteration of your application. If you open the AI Acquire Waveform.vi and then the AI Waveform Scan.vi inside that, you can see that the AI Config.vi is called on the first iteration each time the AI Waveform Scan.vi is called. One way to make your application faster is to use the low level vi's instead and use the AI Config.vi once, at the beginning of your application, and not anywhere else and then run the AI Clear.vi at the end of your application.
One thing you will have to be careful of is making sure that your application does not end without running the AI Clear.vi. When you call the AI Config.vi, the computer reserves resources for the Traditional DAQ drivers, so if you don't release them, it will cause your computer to slow down.
Thank You,
Nick F.
Applications Engineer
