If you follow the procedure that you decribed and open the csv file each time you press stop you will see the following:
Lets say that the first log has 10 entrys for discussion sake.
The second log will have the exact same 10 entrys plus the entrys that occured after pressing start the second time.
It acts like it is set to append to the file but it is not. I believe it is just that the "collector" block retains the data from the previous log session. Because I am not closing the app between each log session the "collector" needs to be "reset" bewteen each log cycle. I am working on doing that but I not sure how yet. What I think I need is a "one shot" that will turn the "reset" input to the "collector" on for one scan of the loop and the off for the rest of the scans. I am not sure how to do this in labview yet. Maybe you know how to do this.
I think I fixed it. I used a shift register, an invert and an and to trigger the reset of the collector on the first scan of the loop. Now the csv log file has only the data from the most recent cycle (the exact same data that is shown in the graph).
Thanks for the help all. I finally have a working app that is useful and versitlie.