LabVIEW状态图模块-Labview 设计模式精讲

LabVIEW状态图模块 状态图—— 用直观的方法来表达基于事件的系统 * Statecharts are an extension of the finite state machine. They were created by David Harel in the 1987 and are part of the UML standard commonly used in embedded system development. ----------------- UML stands for Unified Modeling Language (some say Universal Modeling Language). It is a modeling language consisting of several sublanguages to model structural and behavorial aspects of a software system. UML consists of multiple types of diagrams. The underlying premise of UML is that no one diagram can capture the different elements of a system in its entirety. The nine UML diagrams are: Use case diagram: Identifies the primary elements and processes that form the system. The primary elements are termed as "actors" and the processes are called "use cases“. Class diagram: Defines a detailed design of the system and classifies the actors into interrelated classes. The relationship between the classes can be either an "is-a" or "has-a" relationship. Each class may provide functionality through "methods“. Each class may have certain "attributes" that uniquely identify the class. (3) Object diagram: A special kind of class diagram. An object is an instance of a class. This essentially means that an object represents the state of a class at a given point of time while the system is running. (4) State diagram: Represents the different states that objects in the system undergo during their life cycle. Objects in the system change states in response to events. (5) Activity diagram: Captures the process flows in the system. Similar to a state diagram, an activity diagram also consists of activities, actions, transitions, initial and final states, and guard conditions. (6) Sequence diagram: Represents the interaction between different objects in the system. It is time-ordered. This means that the exact sequence of the interactions between the objects is represented step by step. Different objects in the sequence diagram interact with each other by passing "messages". (7) Collaboration diagram: Groups together the interactions between different objects. The interactions are listed as numbered interactions that help to trace the sequence of the interactions. The collaboration diagram helps to identify all the possible interactions that each object has with other objects. (8) Component diagram: Represents the high-level parts that make up the system. This diagram depicts, at a high level, what components form part of the system and how they are interrelated. A component diagram depicts the components culled after the system has undergone the development or construction phase. (9) Deployment diagram: Captures the configuration of the runtime elements of the application. This diagram is by far most useful when a system is built and ready to be deployed