用户在创建模型时必须知道，Simulink把模块分为两种类型：非虚拟模块和虚拟模块。非虚拟模块在仿真过程中起作用，如果用户在模型中添加或删除了一个非虚拟模块，那么Simulink会改变模型的动作方式；相比而言，虚拟模块在仿真过程中不起作用，它只是帮助以图形方式管理模型。此外，有些Simulink模块在某些条件下是虚拟模块，而在其他条件下则是非虚拟模块，这样的模块称为条件虚拟模块。表2-1列出了Simulink中的虚拟模块和条件虚拟模块。 -The user must know when creating the model, Simulink module is divided into two types: non-virtual modules and virtual modules. Non-virtual module during the simulation work, if the user in the model to add or delete a non-virtual module, then Simulink will change the model of action　In contrast, the virtual module does not work during the simulation, it is only help management model graphically. In addition, under certain conditions, some Simulink blocks is a virtual module, while in other conditions, the non-virtual module, this module is called conditions of virtual modules. Table 2-1 lists the virtual module in Simulink and conditions of virtual modules.