控制系统由上位机、中继单元和模块单元构成。

It is composed of master, relay unit and module unit.

youdao

最后，对光控真空模块单元中的电源系统进行了介绍。

The power supply is also introduced in details in this paper.

youdao

在硬件的基础上设计了包括上位机、中继单元和模块单元在内的软件系统。

And then the software system which includes master, relay unit and module unit was designed on the basis of hardware.

youdao

What we're really getting at is the idea of saying I want to have a way of grouping together information into units that make sense. So I can go back to one of those topics we had at the beginning, which is the idea of abstraction, that I can create one of those units as a simple entity, bury away the details and write really modular code.

组合成为有意义的单元,那么这就让我们回到,一开始讲的话题之一了,这就是抽象的概念,也就是我可以以一个简单的，实体的形式创建这样的一个单元，把具体实现隐藏然后写一些,真正模块化的代码,我们在以后的课程中。

麻省理工公开课 - 计算机科学及编程导论课程节选