Trouble with coding with matlab in Webots

I'm Having trouble with the basic epuck-matlab code that comes installed in webots. I can get the program running but I can't get the simulation to stop and i need it to stop to collect the data. I've tried altering many aspects of the code and playing with the loops. I know i can do the rest of my work if I can get this done because the rest in done in matlab, I'm just lost on the webots side of things.