FBM219 FOXBORO
The IEC61499 project extends IEC61131-3,which is a standard for the architecture of modular distributed systems interconnected through communication internetworking,and will improve IEC61131-3.This is a standardized document based on digital technology for programmable logic control devices to move towards openness at a high level,and is a major trend in the development of PLC.
Development Trends
One or more PLCs are connected to a PC computer to form a system,which serves as the original programmer and human-machine interface operation station.This new trend in the 1990s brought business opportunities for system integration.At the same time,programming software,human-machine interface software(monitoring software or configuration software),and software interfaces(or driver software)have also been developed.
PLC manufacturers have gradually added various communication interfaces and provided a complete communication network on the basis of providing physical layer RS232/422/485 interfaces on the original CPU template.Due to the rapid development of data communication technology,users have strong requirements for openness,and the synchronous development of fieldbus technology and Ethernet technology,the PCS system composed of PLC is slightly better than the current situation of DCS’s openness.Rockwell AB has formed a multi-layer
structure system,including Ethernet Net,Control Net,Device Net,and ASI fieldbuses(which are also compatible with the original DH+network).Siemens has proposed the S7 Routing network,which consists of two layers:Profibus-DP and Industrial Enternet,in addition to the Profibus-DP communication network and Profibus-FMS network.The internet is still developing,and China should actively invest in it.
In 2001,China’s mechanical industry became a new highlight of industrial development,with a total output value increasing by 17.15%compared to the previous year.The production of automobiles ranked among the top 10 in the world,and the production of machine tools ranked fifth in the world.The profit of the mechanical industry increased by 33.35%,
accounting for over 60%of the newly added profit of the entire industry.Exports have also shown promising growth.The machinery industry proposes to implement networking.PLC practitioners should have a clear understanding of this,and pay special attention to the openness of networking,the performance/price ratio of network composition,and the reliability,security,and progressiveness of the network.
The upward connection of the network is an internet problem,and the downward connection is a fieldbus problem.In addition,the existing network can use
Ethernet”e network to the bottom”mode,the network can use client/server mode,browser/server mode,producer/consumer mode,and the interface software can use OPC mode,all of which need to be further implemented.PLC and intelligent MCC motor control center,NC/CNC numerical control equipment matched with CNC machine tools,as well as systems connected with other operation control systems,electronic control equipment,frequency converters,and soft starters;PLC should cooperate with DCS and act as a remote I/O station for DCS;PLC needs to cooperate with IPC for division of labor.In addition to using IPC
