Most of the time you can measure your features just fine, but sometimes, due to manufacturing errors, a feature won't be close to its theoretical (nominal) location, but rather shifted somehow. For Measured features, you need to adjust your theoretical values to handle this situation. However, using the more advanced Auto Features, you can modify the target instead. This will adjust the path accordingly, yet will allow dimensioning to take place relative to the original theoretical values.
Modifying Nominal Values (for both Measured and Auto Features)
PC-DMIS provides you with simple ways to modify the nominal value. To modify the nominal value field in Command mode, place the cursor over the feature then press the F9 key. A dialog box will appear displaying the nominal information which can be updated as necessary.
Modify the nominal information and click OK or Create. The dialog box closes.
If you are modifying a measured feature, PC-DMIS displays a prompt asking if you want to update measured values as well. If you click Yes, the measured values are updated to match the newly entered nominal values. If you click No, the measured values remain what they were.
If you are modifying an auto feature, PC-DMIS asks if you want to update the target values to match the new theoretical values. If you click Yes, the target values are updated to match the newly entered nominal values. If you click No, the target values remain what they were.
Be aware when you have a Feature Control Frame (FCF) dimension and you've customized individual nominal values in that dimension. If you then change the associated nominal values in the feature, a message box appears. If you choose Yes, to update the dimension nominals, PC-DMIS overwrites any previous nominal changes you made to the FCF dimension. For information on FCF dimensions, see the "Using Geometric Tolerances" chapter.
Modifying Target Values (for Auto Features only)
If you have an auto feature, you can choose to modify target values instead of the theoretical values. The target values determine the location where PC-DMIS will try to measure the auto feature. This lets you keep the theoretical values for dimensioning purposes, but still changes the location at which the software attempts measurement. To modify the target values, use the Edit window:
Modifying Target Values Summary Mode: Select the field, press ENTER, type a new a value and press ENTER again to store the change.
Modifying Target Values in Command Mode: Tab to the field to change, type a new value, and press TAB again to store the change.