Parameter Inheritance
All levels of manufacturing features automatically inherit their parameters from an upper-level feature, unless you explicitly modify (customize) a parameter at the current level. That is, Cut Motions and Tool Motions inherit their parameters from the parent NC sequence, while NC sequences may (under certain circumstances) inherit their parameters from sites.
The following the rules apply to the NC sequence parameter inheritance:
• If, at the time of creating an NC sequence, a site of appropriate type is associated with the current workcell, the NC sequence will inherit the parameters of this site. This is called implicit inheritance. If you later modify the parameters of the site, the NC sequence parameter values will be updated accordingly. Also, if you later replace the associated site with another one, or change the workcell associated with the operation, the NC sequence parameters will update to the values in the new site associated with the workcell.
• If you initialize the NC sequence parameters using a site other than the one associated with the workcell, then the NC sequence will inherit the parameters of this site. This is called explicit inheritance. If you later modify the parameters of the site, the NC sequence parameter values will be updated accordingly. However, changing the site associated with the workcell, or the workcell itself, will not affect the parameters of this NC sequence.
• If you initialize the NC sequence parameters using the Retrieve option in the SMM PARAMETERS dialog box, these parameters will be marked as customized.
• Click the Parameters option from the SMT NC SEQUENCE dialog box. The SMM PARAMETERS dialog box appears. If you modify parameter values using this dialog box, parameters will be marked as customized.
Parameters marked as inherited will updated automatically all the way down if you change a parameter value at the upper level. However, if you have explicitly modified a parameter value at a certain level, this parameter will be marked as customized and will not change when you modify parameters at an upper level. Customized parameters can also be inherited by the lower-level features. In other words, if you modify CUT_FEED at the NC sequence level, it will no longer change if you later modify CUT_FEED in the parent site file, but the Cut Motion CUT_FEED will update to the new NC sequence value (unless you explicitly customize it at the Cut Motion level, too).
When you look at the parameters of an NC sequence, Cut Motion, or Tool Motion, the inherited parameter values appear in parentheses. However, if you save a parameters file to disk, this file will list all the parameters without parentheses (because when you retrieve this file into another NC sequence or Cut Motion, these parameters will be marked as customized).