Sub-entities can be classified according to their usage as following.
Parametric variables
A parametric variables such as a Design Variable, Design Point, or Design Frame can be very useful to build a parametric model for design studies such as screening, effect analysis or sensitivity analysis. Characteristics, hard points, and directions for a joint, force or body can be modeled with the parametric variables.
Figure 8.1: List of parametric variables
| Type | Description |
| Design Variable | Use to parameterize a real value in a dialog. |
| Design Point | Use to parameterize a position vector. |
| Design Frame | Use to parameterize an orientation matrix. |
Function entities
Function entities are used to model user-defined formulas for force, contact, motion, output and so on. Various pre-defined functions or subroutines can be used help to build these user functions.
Figure 8.2: List of function entities
| Type | Description |
| Function Expression | Use to build a function using a prescribed rule. |
| User Subroutines | Use to build a user subroutine with a prescribed form. |
| Arguments | Use to set input parameters of a Function Expression or User Subroutines to an entity. |
Equation entities
Equation entities are useful to model a common variable used within several functions or differential equations to represent a control, electrical, magnetic or one-dimensional dynamics system.
Figure 8.3: List of equation entities
| Type | Description |
| Variable Equations | Use to define a user variable in the system. |
| First Order Differential Equations | Use to define a 1st order differential variable. |
| Second Order Differential Equations | Use to define a 2nd order differential variable. |
Auxiliary entities
These entities are accessory entities for use in a User Subroutine or Function Expression. A Simulation Scenario (see below) can help to control the Motion solver.
Figure 8.4: List of auxiliary entities
| Type | Description |
| Arrays | Use to assign storage to exchange a data between several user subroutines or save the data which is calculated from the user subroutine. |
| Strings | Use to define a file path or string for the user subroutine. |
| Splines | Use to define a spline curve for a function expression or user subroutine. |
| Spline3D | Use to define a 3D spline curve for a function expression or user subroutine. |
| Simulation Scenarios | Use to control the Motion solver using an event during simulation. |
Auxiliary entities for body
These entities are used to model a flexible body.
Co-simulation variables
These entities are used to set interface variables during co-simulation with other software applications.