简析自控系统EIA485通讯

Analysis of the EIA485 Communication in Automatic Control System

EIA485标准只定义物理层。Modbus/RTU协议在EIA485物理层上定义了物理链路层和应用层。BACnet/MSTP协议在EIA485物理层上定义了物理链路层、网络层和应用层,简单介绍ASN.1抽象语法标记在通讯编码解码的作用,举例介绍网络层在跨网络数据采集数据的作用。从EIA485到Modbus/RTU到BACnet/MSTP的发展过程,观察最新技术成果如何持续提升自控系统技术并始终处于不断发展和创新之中。

The EIA485 standard only defines the communication physical layer.The Modbus/RTU protocol defines the physical link layer and application layer on the EIA485 physical layer.The BACnet/MSTP protocol defines the physical link layer,network layer,and application layer on the EIA485 physical layer,briefly introduces the role of ASN.1 abstract syntax notation in communication encoding and decoding,and provides examples to illustrate the role of network layer in cross network data collection.From EIA485 to Modbus/RTU to BACnet/MSTP,observe how the latest technological achievements continuously improve the development and innovation of automaticcontrol system technology.