6.2.3.10. OnOff
An OnOff joint is a constraint for a selected translational or rotational degree of freedom of the action reference frame. Either of x, y, or z component of the action marker relative to the base marker is constrained. These constraints can be turned on or off by the specified function. The definition of a valid function expression is explained in Function Expression.
![../_images/image341.png](../_images/image341.png)
Figure 6.224 OnOff icon on Working Window
6.2.3.10.1. Modeling Options
The user can create a joint entity as follows.
Body, Body, Point
Body: Selects a base body of the onoff joint.
Body: Selects an action body of the onoff joint.
Point: Selects a point to define the location of the onoff joint.
Body, Body, Point, Direction
Body: Selects a base body of the onoff joint.
Body: Selects an action body of the onoff joint.
Point: Selects a point to define the location of the onoff joint.
Direction: Defines the z-axes of base and action markers.
Body, Body, Point, Direction, Direction
Body: Selects a base body of the onoff joint.
Body: Selects an action body of the onoff joint.
Point: Selects a point to define the location of the onoff joint.
Direction: Defines the z-axes of base and action markers.
Direction: Defines the x-axes of base and action markers.
6.2.3.10.2. Properties
The user can define constraints and conditions using the Joint page.
![../_images/image343.png](../_images/image343.png)
Figure 6.225 OnOff joint property page [Joint page]
Type: Shows the type of joint.
Constraint: Specifies the degree of freedom to be constrained as Translational X, Translational Y, Translational Z and Rotational X, Rotational Y, Rotational Z. And the user selects DOF combinations.
For Example
Fixed Condition: All Constraint is selected. (default)
Spherical Condition: Translational X, Y, and Z constraints are selected.
Expression: Defines the expression of the OnOff.
Include On Condition: The constraint can be turned on by expression. If the check box is checked and the expression value is not equal to zero, the OnOff joint works as a constraint. The default is unchecked. It means the OnOff joint works as a constraint.
Force Display: Displays the resultant force vector graphically on Working Window.