How to record data using booleen (True or false) as trigger?

[DrWang]

An oscilloscope is connected to a computer, inputing two waves, a square wave and a sine wave.

In the .vi file included, a square wave is converted into true or false signals (the upperpart in the while loop), the lower part in the while loop is a sine wave. I would like to record the amplitude of the sine wave exactly at the true signal (which is the rising edge in the square wave), and stream this into a text file continuously.

How can I achieve this?

Any help is greatly appreciated, thank you!

[crossrulz]

1. You typically just look for the square wave to be above a certain threshold to say if it is high or low.  So no need for the Derivative function.

2. Use the Boolean Crossing PtByPt to determine if the signal changed from False to True.