Tip voltage is measured voltage from the tip and the Z axis is raised or lowered in the parameters of the DTHC. For instance if you have 125 tip volts you will be roughly .130" above the material and maintaining that balaance in corners (using antidive #'s) is the function of the DTHC. There are some dumb DTHC units out there that do not have antidive and will lower the tip while making a corner. This is not the case with this unit proper tip volts and the reading frequency of those tip volts will determine the Z axis movements. You will understand everything when you get the electronics.