I wanted to setup my table limits today [VL] but I can't seem to figure it out. Can someone please explain how I should be using them?

I have been using my limit switches to home my X & Y axis (at their low limits) for a while now, but for some reason I can't get them to stop the carriages at their high limits. I see the light on the sensor come on when I roll over the switch (using the keypad), but it doesn't stop the travel. I was attempting to use the sensors to manually determine the high limits of the X & Y travel so that I can enter them into [VL], but maybe that's not how it's supposed to be used. I stumbled into [VL] after reading a post where someone (Michael Schwartz I believe) had set his low Z limit to -.02 so that he couldn't accidentally cut too deep into his table & I thought it was a good idea.

I was planning on entering a dimension .01 smaller than the low & high limits. Is that suggested?