Answer: Relying on advanced industrial network technology, production and management data can be quickly and effectively collected and transmitted. Therefore, the importance of the network in automation system integration engineering is becoming more and more significant, and some people even put forward the view that "the network is the controller".
PLC has the function of communication networking, which enables information to be exchanged between PLCs, PLCs and host computers and other intelligent devices to form a unified whole and achieve decentralized and centralized control. Most PLCs have RS-232 interfaces, and some have built-in interfaces that support their respective communication protocols.
PLC communication has not yet achieved interoperability. IEC has stipulated a variety of fieldbus standards, which are adopted by all PLC manufacturers.
For an automation project (especially a medium- to large-scale control system), network selection is very important. First of all, the network must be open to facilitate the integration of different devices and the expansion of future system scale; secondly, the choice of network form based on the transmission performance requirements of different network levels must be based on a deeper understanding of the network standard protocols and Mechanism; Third, comprehensive consideration of specific issues such as system cost, equipment compatibility, on-site environment applicability, etc., to determine the network standards used at different levels.
