Hi Richard, your DSP is running as it should.
What you have mistakenly done is created a new work coordinate position,i.e you have told the DSP that you want to set your 0,0,0 position to a different part of the table. Your controller has the ability to set 9 different work coordinates.
This can be easily demonstrated to you if you turn on your machine again and after it travels to its home position. Press "MENU" + "0" together.
Your DSP will now display a letter in front of it (Im sorry, I am not in front of my machine and cant remember which letter it is,it may be "A"). This is the absolute position of your Machine. If you now press "MENU" + "1" together, you will see that the letter changes to the number 1. Now move your machine closer to the table and to a position where you would like to have your 0,0,0 set.Once this is done set your work origins in all 3 axes. If you now repress "MENU" + "0", you will see that the coordinates have changed. This is the absolute position of your machine. Multiple work coordinates is a handy feature if you are machining more than one item on the table.
Hope my explanation makes sense to you.
"MENU" + "0 - 9" will give you either a local work coordinate or the absolute machine coordinates.
Being over the x or y limit was most likely caused because the 0,0,0 position of the 4th local working coordinates was probably in the middle of the machine and you were asking it to push too far from the local 0,0,0 position than physically possible.
Hope thats explains it.