About Parameters

When you create a part like a hollow cylinder, you often start by creating a sketch, then you create a pad by extruding the initial sketch, then you add other features to the created pad. The final document is made up of features which define the intrinsic properties of the document. Removing one of these features results in a modification of the document. These features are called parameters. Parameters play a prominent role in Knowledgeware applications. They are features that can be constrained by relations and that can also be used as the arguments of a relation.

In addition to these parameters, CATIA allows you to create user parameters. These user parameters are extra pieces of information added to a document.

User parameters are very handy in Knowledgeware applications:

They can be used to add specific information to a document

They can be defined or constrained by relations

They can be used as the arguments of a relation.

A given relation may take as its arguments both types of parameters (intrinsic and user).

Displaying Parameters in the Specification Tree

The user parameters are displayed in the specification tree provided you check the Parameters box in the Display tab in the Tools>Options>Infrastructure>Part Infrastructure dialog box. The user parameter list contains at least the Material parameter. The initial value of the Material parameter is set to None.

In addition, parameters can be displayed with their values provided you check the With Value box below the Parameter Tree View settings in the Tools>Options>General>Parameters and Measure dialog box

Parameters and National Support Languages

CATIA users working with non-Latin characters must check the Tools>Options>General>Parameters and Measure>Knowledge tab>Parameter Names>Surrounded by the symbol'. Otherwise, parameter names must be renamed in Latin characters when used in formulas.

Editing a Parameter

You can access a parameter contextual menu by right-clicking this parameter in the specification tree.

	The `Definition...` command enables you to access the Edit Parameter window where you can edit the parameter value.
	The `Edit formula...` command enables you to access the formula editor to add a formula to the parameter.
	The `Hide` command enables you to hide the parameter. In this case, it will not display in the specification tree.
	The `Reorder...` command enables you to reorder parameters.
	The `Lock...` command enables you to lock the parameter.

When working with parameters of Length and Angle type, you can also use the Create Equivalent Dimensions command. For more information about this command, see Getting Familiar with the Equivalent Dimensions Interface or Using the Equivalent Dimensions Feature.

Hiding a Parameter

You can hide a parameter by right-clicking this parameter in the specification tree and by selecting the Hide command.

A visual indicator located at the parameters set level indicates that the set contains hidden parameters. Note that this indicator is not recursive.
If you try to delete a parameters set containing hidden parameters, a message is displayed asking if you want to delete the parameters set that contains hidden parameters. Note that if you try to delete a parameters set containing another parameters set with hidden parameters, the message will be displayed.

Working with External Parameters

External parameters are parameters that point parameters located in another document. There are 2 types of external parameters depending on their links:

Reference link type: Both parameters are located in 2 different documents.
Contextual link type: Both parameters are located in 2 different documents located in the same assembly.

External Parameters Contextual Menu

You can access the external parameters contextual menu by right-clicking the external parameter in the specification tree. Note that these functionalities can also be accessed in the Edit links dialog box.

	`Hide`: Enables you to hide a parameter. In this case, it will not display in the specification tree
	`Reorder`: Enables you to reorder parameters (if you have created more than 1 external parameter.)
	`Lock`: Enables you to lock an external parameter.
	`Open the Pointed Document`: Enables you to open the pointed parameter.
	`Isolate`: Enables you to isolate the parameter.
	`Activate`/`Deactivate`: Enables you to activate/deactivate the parameter. For more information, see Deactivating and Activating External Parameters.