For a machine supporting DCC Motion, the following parameters appear in the column headings of the Focus tab when focusing a part:
Control (Focus): AUTO control performs a focus operation based upon the previously determined values collected during the focus calibration of the "Optics Calibration" procedure. PC-DMIS will automatically set the range and speed to be optimal for your vision machine. FULL control allows you to manually set the range and duration values.
Motion (Focus): On systems with a configured rotary, the motion used to execute a focus operation can be a linear move utilizing the XYZ axes or a rotary move. If a rotary motion type is selected, the range and surface variance values is for rotary focus and is in decimal degrees. The default range and surface variance values for linear and rotary focus are saved separately.
Range (Focus): This indicates a focal range (in the current units) within which to perform the auto focus. The search for the best focal position within that range takes place (usually in the Z-axis). The available range values vary based on each system’s specific parameters. You can edit this parameter by double clicking and entering a different value.
Duration (Focus): This displays the number of seconds to spend searching for the best focal position for auto and manual focus. You can edit this parameter by double clicking and entering a different value.
As a general rule of thumb, you should aim to make your duration at least twice as large as the range.
Find Surface (Focus): This displays a YES or NO. Setting this option to YES causes PC-DMIS to perform a second, slightly slower, pass-to attempt to improve the accuracy of the focal position. The second pass is optimized based on the image data of the first pass and the Numeric Aperture of the current lens. This is useful when measuring a surface that varies in height, requiring a large range to over which to focus.
Surface Variance (Focus): With the Find Surface option set to YES, this value is used to determine the distance that is initially scanned at a fast speed to locate the part, and then the normal focus is done around this area. Once the focal position is found, PC-DMIS does a quick focus scan in that region. This is useful for parts where variability means the focus position can vary a lot.
Assist (Focus): This is used with systems with a laser or Projected Grid device. These devices can be switched to "ON" to assist with the focus as on certain surfaces by improving the contrast. Set this option to "GRID" to enable this functionality.
SensiLight (Focus): This determines whether or not the machine should perform an auto-light adjust prior to focus, in an attempt to achieve optimal focus result. If set to NO, PC-DMIS sets lighting according to the learned percentage, and the brightness is not adjusted automatically. SensiLight is short for "sensible lighting".