About Global Parameters
Parameters created in a notebook are global, and they can be accessed in other modes. Declare the notebook and use local relations to declare the global parameters to the local ones. Once declared, dimension values and relations specified in a notebook can directly affect the values of component dimensions in an assembly. Use a Parameter Table to assign different parameter values and relations to different component configurations.
Notebook dimensions are created as parameters with a name and a numeric value. To switch between viewing dimension values or names in the Notebook window click Tools > Switch Symbols.
Notebook sketches are nonparametric. They do not update when the Notebook dimensions are changed.
To create user-defined global parameters, you write defining relations. All models declared to the active notebook can then access these variables. Relations are user-defined rules for dimensions. For example, you have defined the relation XYZ = 27.4 * 1.7 in a notebook. When you access the parameter XYZ in other modes through local relations, the value is calculated from the global relation.
The following restrictions apply to relations in Notebook mode:
Only global relations can be defined in Notebook mode.
A relation created in another mode cannot be accessed in Notebook mode.
Relations are not automatically reevaluated. To evaluate them click  from the Relations dialog box or regenerate the notebook.
For more information on parameters and relations, search the Help Center.