中文说明：这些代码对于数字控制系统非常有效。这些代码帮助学生介绍、恢复和增强他们的系统，并用数字方法控制他们的系统。
English Description：
these code is very efficient for digital control system these code help students to introduce and Restoration and enhancement their systems and control their with digital method. digital control is newest method to control modern system