The State Diagram shows allowable modes and the events that cause the transition between modes. In general, a State Diagram used for System Modes Modeling requires less detail than State Diagrams used for Dynamic Modeling.
You can create a State Diagram through the context menu of a State Machine:
• Right-click the State Machine, point to New, and then click State Diagram.
When the UML Profile is present in the Model, you can create a State Diagram from an Actor, Class or Use Case (Modeler creates a State Machine to own the State Diagram):
• Right-click a Actor, Class the Use Case, point to New, point to UML, and then click State Diagram (via State Machine).
Note that when you create a State Machine from a Class or Interface, Modeler also creates a State Diagram as a child of the new State Machine.
A State Machine can own many State Diagrams.
The following sections provide information about how a State Diagram is used in the model. For more information about an item, property or model part, click it.
For most diagram symbols, you can change the presentation of the symbol through the Style view options (See
Style view options - all diagrams), and change the showing of Stereotypes and Tag Definitions through the Stereotypes view options (See
Stereotypes view options for a symbol - all diagrams). When a symbol has additional view options for changing its presentation, this icon is shown - to see how the view options can change the presentation, click the icon.
is shown - to see how the view options can change the presentation, click the 
Activity (as a Do activity)
Operation(as a Do activity)
State Machine (attached to frame)
Atomic State
Concurrent State
Comment
Connection Point Reference
Constraint
Dependency
Entry State
Event Action Block
Exit State
Final State
Fork State
History State
Initial State
Join State
Junction State
Sequential State
Submachine State
Transition
State Model
Stereotype