PLC在过程控制的发展将是一智能变送器和现场总线，暨向下拓展功能，开放总线。
2、相同点
在微电子技术发展的背景下，从硬件的角度来看，PLC、工业计算机、集散系统(DCS)之间的差别正在缩小，都将由类似的一些微电子元件、微处理器、大容量半导体存储器和I/O模件组成。编程方面也有很多相同点。
3、区别点
controller supports Profibus, FF, ModBus, Can, etc.
International standard fieldbus, Profibus is the most widely used open fieldbus international standard in the world, divided into FMS, DP and PA
Level 3, DP communication rate can be as high as 12Mb. Profibus is used to connect intelligent devices such as distributed I/0 stations and field bus instruments.
Communication between the process station, operator station and engineering station takes place via the system bus DigiNetS (Industrial Ethernet). user
Different transmission media (RJ45 twisted pair, thin, thick or fiber optic cables and mixed media) and network topology can be selected for the system bus.
Simple layout, due to the use of TCP/IP protocol, the system can also use the public telephone network (dial-up mode) or satellite to achieve ultra-long-distance communication.
Subsystems such as PLC communicate with the Industrial” system through the ModBus protocol interface. The system also supports IEC870-5 over-control protocol.
discussion.
The Flash EPROM inside the PS provides more than 220 functional modules (control algorithm subroutines), in addition to the basic ones specified in the IEC 61131 3 standard
In addition to this content, many powerful and rigorously
