THCADCS是清华大学计算机系控制教研组研制的交互式程序包,它可用于控制系统的分析、设计、仿真以及控制系统的模型转换等方面。THCADCS的交互性主要是通过命令来实现的。用户从终端输入所选择的命令,计算机进行相应的动作。一条命令通常与一个应用子程序相对应。各应用子程序间的信息传递是通过每个命令所带的命令参量表来实现的。参量表的使用比较灵活,用户可以自由命名参量表中的变量,甚至有的命令参量表中的变量个数也是可以选择的。考虑到不同类型用户的需要,该程序包还提供了其他可供选择的交互方式,例如问答式,它可一步一步地指导用户;文件式,它使用户只要 THCADCS is an interactive package developed by Computer Science Teaching and Research Group of Tsinghua University. It can be used in analysis, design, simulation of control system and model conversion of control system. The interactivity of THCADCS is mainly achieved through command. The user inputs the selected command from the terminal, and the computer performs the corresponding action. A command usually corresponds to an application subroutine. Information transfer between application subroutines is carried out through the command parameter list that each command brings. The use of parameter tables is more flexible, the user can freely name the variables in the parameter list, and even the number of variables in the command parameter list is optional. Taking into account the needs of different types of users, the package also provides other alternative ways of interaction, such as question-answering, which can guide users step by step; file-style, which allows users to only