Art did a bang-up job putting together a pair of tutuorial videos for Mach3:

http://www.machsupport.com/Inputs-Ou...ts-Outputs.swf

Even though the tutorial is for Mach3, I think he did an outstanding job of explaining how to jog back off of the limit switch when you trigger an error and the system goes into reset mode. At least that part of it should pertain to Mach2 users too.