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。組合式結構的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。

SIMATIC S7-400 PLC S7-400 PLC is a programmable controller for medium and performance range. S7-400 PLC adopts a modular fan free design, which is reliable and durable. At the same time, it can choose a variety of levels of CPU (function is gradually upgraded), and is equipped with templates with a variety of general functions, which enables users to combine them into different ones according to their needs. When the control scale is expanded or upgraded, as long as some templates are properly used, it can be upgraded and fully needed. PLC combination
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.