IS200NATCH1CPR3 GE

PLC application systems can be roughly divided into three categories:centralized,remote,and distributed control systems.

1.Centralized control system

The centralized control system uses a PLC to control one or more controlled devices.It is mainly used for occasions where the number of input and output points is small,the positions of the controlled devices are relatively close,and there is a certain relationship between the actions of each other.It is characterized by a simple control structure.

2.Remote control system

PLC transmits information with the controlled equipment through the communication cable.The remote control system means that the control unit is far away from the control site.This system is generally used in situations where the controlled equipment is very scattered,or the working environment is relatively harsh.Its characteristic is that it needs to use a remote communication module,which increases the cost and complexity of the system.

3.Distributed Control System

This system is mostly used in large-scale control systems with multiple controlled devices,where there is data information transmission between the controlled devices.Its characteristics are that the system has strong flexibility and a large control range,but it needs to increase the hardware and software for communication,and the complexity of the system is also greater.

PLC应用系统大致可以分为三类：集中式、远程式、分布式控制系统。

1.集中式控制系统

集中式控制系统是用一个PLC控制一台或多个被控设备，主要用于输入、输出点数较少，各被控设备所处的位置比较近，且相互间的动作有一定联系的场合。其特点是控制结构简单。

2.远程式控制系统

PLC通过通信电缆与被控设备进行信息传递。远程式控制系统是指控制单元远离控制现场，该系统一般用于被控设备十分分散，或工作环境比较恶劣的场合。其特点是需要采用远程通信模块，提高了系统的成本和复杂性。

3.分布式控制系统

该系统多用于有多台被控设备的大型控制系统，其各被控设备之间有数据信息传送的场合。其特点是系统灵活性强、控制范围大，但需要增加用于通信的硬件和软件，系统的复杂性也更大。