New problem: How can I use DAQmx timing in the loop instead of "wait" vi?

Dear NI family,

Hi there!

1. How can I use DAQmx timing in the loop instead of "wait" vi?

I hope to use the function of DAQmx Timing, such as setting timing sources, changing duty cycle of timing, setting rate and samples per channel.

2. When I click the button "STOP", there always will be LEDs turned on, what should I do to shut all the leds down when I click the STOP button?

Could you please show me how to fix the problems? The code is in the attachment.

Thanks a lot!

Best,

Jason