I'll start by saying that in no way am I well versed in subs, and other code. Most of what I have told you here, and prior post, I dug up in the manual, and referred to prior sub test of my own. I have no idea about boss 6 methods, but from an uneducated guess, I would guess they had their own proprietary code/rules. This is pretty common, especially among older machines and the younger days of NC. You might want to go through the Mach manual, and stick to the methods enclosed. I do believe they are pretty much the industry standard. As far as the Z depth for the subs, it really depends on what your wanting, and how you want to do it. There's more than one way to skin that cat, and giving out misguided advise would certainly not be beneficial to you, or others. I have attached two files that demonstrate basic subs. They both cut a square perimeter, and have two Z depths. The only difference being that the subs are incremental in one file, and absolute in the other. The main program in both are absolute. These should give a general method of construction to learn upon. I believe that to be of any further use for what your trying to accomplish, one would need a detailed description, or even better, a dimensional drawing of exactly what your wanting to cut. If it's not overly difficult/time consuming, I'm sure someone can whip up a program for you, and you can pick it apart to see the exact methods used.