DCC Settings

DCC Settings

DCC Settings in CMM-Manager define the automated machine drive speeds and probe clearance distances when operating in Direct Computer Control (DCC) mode.

These settings govern how the probe travels through space and contacts part surfaces using five primary parameters:
  1. Move Speed: The velocity at which the CMM positions the probe head between features and clearance points in open air.
  2. Touch Speed: The reduced velocity the probe uses as it approaches and touches the part surface to take a measurement point.
  3. Approach Distance: The distance from the nominal target location where the probe path turns perpendicular to the surface and slows down from Move Speed to Touch Speed.
  4. Backoff Distance: The distance the probe retracts straight back from the part surface after registering a touch. This value also affects the amount of backoff during the manual (joystick) measurement.
  5. Search Distance: The extra distance the CMM continues driving past the expected target point to detect a surface before halting with a "NO TOUCH DETECTED" warning.
In CMM-Manager, you can apply these settings globally at the start of a program in Program Settings, update them mid-sequence using a DCC Settings command, or selectively customize them for a specific geometry by checking Overwrite DCC Parameters in the feature's measurement window.

Program Settings


To adjust global DCC settings across your entire part program in CMM-Manager, follow these steps:
  1. Open Program Settings: At Line 001 at the very top of the Program Database tree, double-click Program Settings. This line is automatically generated by CMM-Manager when a project is initialized and cannot be moved or deleted.
  2. Unlock Editing: If needed, click the padlock icon in the upper-left corner of the Program Settings dialog window to unlock editing privileges.
  3. Select the DCC Tab: Click the DCC tab at the top of the dialog box.
  4. Enter Your New Values: Type your desired global values into the white text boxes for Move Speed, Touch Speed, Approach Distance, Backoff Distance, and Search Distance. The minimum and maximum allowable limits set by your machine driver are displayed next to each text box.
  5. Save Changes: Click Apply and then OK.
Once saved, every automated feature measurement in your program tree will inherit these global motion values, unless you explicitly choose to override them on an individual feature or by using the DCC Settings command.

DCC Settings Command


The DCC Settings command is a mid-program operation inserted directly into the CMM-Manager Program Database during Teach-On Mode.
Unlike updating the root Program Settings (which changes defaults for the entire file), inserting a DCC Settings command alters the global motion parameters—such as Move Speed, Touch Speed, Approach Distance, Backoff Distance, Search Distance, and Accelerations—starting at that specific step in the program sequence onward

Why Use a Mid-Program DCC Settings Command?

It is ideal when part geometry requires a temporary change in machine behavior for a group of features. For example, you might want to:
  1. Slow down all movement when entering a narrow, deep cavity or measuring delicate thin-walled features.
  2. Increase move speed when transitioning across long open spans between external feature groups.
  3. Reduce Approach and Backoff Distances to be able to measure a small hole without a collision.

How to Insert a DCC Settings Command

  1. Open DCC Settings: On the Ribbon Bar, navigate to the Features Tab, locate the Teach Group, and click the More Teach Command button on the bottom right corner of the group to find the DCC Settings command.

  2. Configure New Parameters: Enter your updated values for speeds, accelerations, or distances in the white text boxes.
  3. (Optional) Restore Baseline Settings: If you want to end a temporary speed override and return to your initial program baseline, select the Restore to initial machine settings check box.
  4. Commit to Program: Click OK
CMM-Manager will insert a discrete DCC Settings command line into your Program Database. All measurement operations executed after this line will use the updated motion settings until the program encounters another DCC Settings command or finishes running.

Overwrite DCC Parameters


Overwrite DCC Parameters is an option setting in CMM-Manager that allows you to customize DCC motion settings for an individual feature rather than using the program's global defaults.

To use Overwrite DCC Parameters in CMM-Manager:
  1. Open Feature Measurement: Open the measurement window for your target feature (such as CAD Measure 2D Circle, CAD Measure Slot, CAD Measure 3D Cylinder, or Measure Plane)
  2. Check the Overwrite Box: On the Measurement tab, check the Overwrite DCC Parameters box.
  3. Access the DCC Tab: Checking this box dynamically adds a dedicated DCC tab to the dialog box.
  4. Adjust Local Parameters: Select the DCC tab and enter your custom local values for Move Speed, Touch Speed, Approach Distance, Backoff Distance, or Search Distance.
  5. Commit the Change: click OK to save the operation. The measurement path will update accordingly.

Adjusting DCC Parameters for Teach-Off and Run Modes


If measurements need to be performed in Teach-Off or Run mode, the Approach & Backoff Distances and other DCC settings can be adjusted through the DCC section of Machine Properties.

Machine Properties can be accessed either through the Status Bar (More... button at the bottom-left corner of the screen) or through the Ribbon Bar (System tab → Machine Properties).

Notes
Modifying these values in Machine Properties will not affect the DCC settings used in the current program. This is why the window is grayed out in Teach-On mode.