PM856AK01 3BSE066490R1 ABB

The closed-loop controller,analog data collector and logic operator can be directly connected to the communication network with the man-machine interface,and each different controller on the network acts as an independent node on the network.Each node performs a different function.They should all have network interfaces.In order to save the network interface,some DCS connect all the equipment used for process control,that is,the closed-loop controller,the analog data collector and the logic operator,on the control bus in advance,which is called the process control station.This can increase the number of I/O points that the process control station can receive,and save the interface.Then connect to the network through the interface,and connect with the man-machine interface.With the development of computer technology,the computing ability of the controller is continuously enhanced.For example,a controller made by a PC has a strong ability,which can receive both analog operation and switch logic operation.A controller becomes a node on the network.Connect with the HMI through the network.

闭环控制器、模拟量数据采集器和逻辑运算器可以和人机界面直接连在通讯网络上，在网络上的每一个不同的控制器作为网络上的一个独立结点。每一个结点完成不同的功能。它们都应有网络接口。有的DCS为了节省网络接口，把所有的过程控制用的设备即闭环控制器、模拟量数据采集器和逻辑运算器预先连在控制总线上，称为过程控制站。这可以增加过程控制站能接收的I/O点数，又能节省接口。然后再通过接口连到网络上，与人机界面相连。随着计算机计术的发展，控制器的运算能力不断增强，如PC机做的一个控制器能力很强，既可接收模拟量运算，也接收开关量逻辑运算。一个控制器成为网络上的一个结点。通过网络与人机界面相连。