Prehit / Retract box
Use the Prehit / Retract box to define a distance value away from the part or calibration tool. The speed of PC-DMIS decreases to the defined touch speed while within this distance. It remains at the touch speed until the hit is taken and the distance is reached again. At that point, PC-DMIS returns to the defined move speed.
Some controllers do not retract on their own. In these cases, PC-DMIS issues the move to do the retract, and the distance is based on ball surface to the part's theoretical hit location. If the controller does do the retract, the distance may be calculated either from the ball surface or the ball center to either the theoretical or measured hit location, depending on the controller.