若干個模塊，如CPU模塊、輸入模塊、輸出模塊、電源模塊等等。其中各模塊功能比較單一，模塊的種類卻日趨豐富。比如，一些可編程序控制器，除了－些基本的I/O模塊外，還有一些特殊功能模塊，像溫度檢測模塊、位置檢測模塊、PID控制模塊、通訊模塊等等。組合式結(jié)構(gòu)的PLC特點是CPU、輸入、輸出均為的模塊。模塊尺寸統(tǒng)一、安裝整齊、I/O點選型、安裝調(diào)試、擴展、方便。疊裝式疊裝式結(jié)構(gòu)集整體式結(jié)構(gòu)的緊湊、體積小、安裝方便和組合式結(jié)構(gòu)的I/O點搭配靈話、安裝整齊的優(yōu)點于一身。它也是由各個單元的組合構(gòu)成。其特點是CPU自成的基本單元（由CPU和一定的I/O點組成），其它I/O模塊為擴展單元。在安裝時不用基板，僅用電纜進行單元間的聯(lián)接，各個單元可以一個個地疊裝。使達到配置靈活、體積小巧。SIMATIC S7-200 PLC S7-200 PLC是超小型化的PLC，它適用于各行各業(yè)，各種中的自動檢測、監(jiān)測及控制等。S7-200 PLC的強大功能使其無論單機運行，或連成網(wǎng)絡(luò)都能實現(xiàn)復(fù)雜的控制功能。 S7-200PLC可提供4個不同的基本型號與8種CPU可供選擇使用。

Several modules, such as CPU module, input module, output module, power module, etc. Among them, the functions of each module are relatively single, but the types of modules are becoming more and more abundant. For example, in addition to some basic i/o modules, some programmable controllers also have some special function modules, such as temperature detection module, position detection module, PID control module, communication module and so on. The PLC with combined structure is characterized by modules with CPU, input and output. The module size is unified, the installation is neat, the i/o point selection, installation and debugging, expansion and convenience. The stackable stackable structure integrates the advantages of compact integral structure, small volume, convenient installation and the combination of i/o points, smart words and neat installation. It is also composed of the combination of various units. It is characterized by the basic unit of CPU (composed of CPU and certain i/o points), and other i/o modules are expansion units. During installation, there is no base plate, and only cables are used for connection between units. Each unit can be stacked one by one. Make the configuration flexible and compact. SIMATIC S7-200 PLC S7-200 PLC is a super miniaturized PLC, which is suitable for automatic detection, monitoring and control in all walks of life. The powerful function of S7-200 PLC enables it to realize complex control functions whether it is running alone or connected into a network. S7-200PLC can provide 4 different basic models and 8 kinds of CPUs for selection.