What is Industrial Ethernet
—- Industrial Ethernet is a powerful area and unit network based on IEEE 802.3 (Ethernet). Using industrial Ethernet, SIMATIC NET provides a seamless integration into the new multimedia world.
—- The wide range of applications provided by intranets, extranets, and the Internet have not only entered today’s office space, but are also used in production and process automation. Following the successful operation of 10M baud Ethernet, the switched, full-duplex and adaptive 100M baud Fast Ethernet (IEEE 802.3u compliant) has also been successfully operated for many years. The performance of Ethernet depends on the needs of the user. Universal compatibility allows users to seamlessly upgrade to new technologies.
Benefits for users
—- With a market share of 80%, Ethernet is without a doubt the number one network in the LAN(local area Network) space today. The superior performance of Ethernet brings great benefits to your application:
Quick assembly with simple connection.
Continuous compatibility is provided through continuous development, thus ensuring the security of the investment.
Provides virtually unlimited communication performance through switching technology.
A wide variety of networking applications, such as networking in office environments and production applications.
Access to WAN(Wide Area Network) enables communication between companies, for example, ISDN or Internet access.
—-SIMATIC NET Based on field-proven technology,SIMATIC NET has supplied more than 400,000 nodes worldwide for use in harsh industrial environments, including areas with high levels of electromagnetic interference.
The construction of industrial Ethernet network
—- A typical industrial Ethernet network environment has the following three types of network devices:
Network component
Connecting parts:
FC fast connection socket
ELS(Industrial Ethernet Electrical Switch)
ESM(Industrial Ethernet Electrical Switch)
SM(Industrial Ethernet Fibre Channel Switch)
MC TP11(Industrial Ethernet Optical Fiber Electrical Conversion Module)
Communication media: ordinary twisted pair, industrial shielded twisted pair and optical fiber
Industrial Ethernet communication external manager on SIMATIC PLC controller. Used to connect SIMATIC PLC to industrial Ethernet.
Industrial Ethernet communication external manager on PG/PC. Used to connect PG/PC to industrial Ethernet.
Important performance of industrial Ethernet
—- To ensure the safety and reliability of industrial applications in harsh industrial environments, SIMATIC NET adds a number of important features to Ethernet technology:
Industrial Ethernet is technically compatible with IEEE 802.3/802.3U and uses ISO and TCP/IP communication protocols
10/100M adaptive transmission rate
Redundant 24VDC power supply
Simple cabinet rail mounting
Easy to form star, line and ring topologies
High speed redundant secure network with a maximum network reconstruction time of 0.3 seconds
Network components for harsh environments, EMC tested
The Fast Connect connection technology with RJ45 technology, industrial grade Sub-D connection technology and installation of special shielded cables ensures fast cable installation on site
Simple and efficient signaling devices constantly monitor network elements
Compliant with SNMP(Simple Network Management Protocol)
Web-based network management is available
Use VB/VC or configuration software to monitor and manage the network
In today’s era, the concept of network is control has been more and more accepted by users. The traditional distributed control system based on RS485, CAN and other buses, due to its inherent defects, is being replaced by the industrial network based on TCP/IP protocol. The industrial Ethernet bus is consistent with the local area network we are using now. It uses the unified TCP/IP protocol to avoid the trouble of communication between different protocols, it can directly interconnect with the LAN computer without additional hardware equipment, it facilitates the sharing of data in the LAN, it can use Internet Explorer browser to access the terminal data, rather than special software. It can and the existing LAN based ERP database management system to achieve seamless connection, it is particularly suitable for remote control, with the telephone exchange network and GSM, GPRS wireless telephone network to achieve remote data acquisition, it uses a unified network cable, reduce the wiring cost and difficulty, to avoid a variety of buses coexist. Because of its many advantages, the industrial Ethernet bus has gradually gained rapid popularity at home and abroad, and now there are a large number of supporting products in use. Such as industrial Ethernet HUB, industrial Ethernet firewall production, industrial Ethernet gateway, Ethernet to RS232/RS485 equipment, Ethernet A/D module, Ethernet D/A module, Ethernet AI module, Ethernet AO module, Ethernet DI module, Ethernet DO module and composite function module.
A few years ago, when the fieldbus wars were raging, Ethernet, traditionally used in offices and businesses, quietly entered the control space. Recently Ethernet is moving to the foreground, developing rapidly, quite eye-catching. The reason is due to the development of the industrial automation system’s positive distribution and intelligent real-time control, among which, communication has become the key, and users’ requirements for unified communication protocols and networks are increasingly urgent. On the other hand, the rapid development of information technology such as Intranet/Internet requires enterprises to achieve comprehensive seamless information integration from the field control layer to the management level, and provide an open infrastructure, but the current fieldbus can not meet these requirements. It should be said that the emergence of fieldbus does bring a deep revolution to industrial automation, but a variety of fieldbuses are incompatible with each other, the controllers of different companies can not achieve high-speed real-time data transmission between each other, the information network there is a protocol gap leading to the emergence of “automation islands”, prompting people to seek a new way out, and pay attention to Ethernet. Ethernet has the following advantages:
(1) has a fairly high data transmission rate (currently up to 100Mb/s), can provide enough bandwidth;
(2) Ethernet and TCP/IP are easily integrated into the IT(information technology) world because they have the same communication protocol;
(3) can run different transmission protocols on the same bus, so as to establish the public network platform or infrastructure of the enterprise;
(4) The use of interactive and open data access technology throughout the network;
(5) Used for many years, has been familiar to many technical personnel, the market can provide a wide range of setting, maintenance and diagnostic tools, become the de facto unified standard;
(6) Allow the use of different physical media and constitute different topologies.
As for the uncertainty and poor real-time performance of Ethernet, it has been basically solved because of the use of intelligent hubs, the implementation of active switching function, the introduction of priority and duplex wiring. By increasing the data transmission rate, carefully choosing the topology of the network and limiting the network load, the probability of data collision can be minimized. In addition, for example, Hirschmann has developed a range of hardened, sealed and vibration-resistant Ethernet devices suitable for industrial environments, such as rail transceivers, hubs, switchers, connectors, etc. Woodhead Connectivity introduces the RJ-45 connector with IP67 protection. All these have created conditions for Ethernet to enter the field of real-time control. Because of this, ARC(Automation Research Company) predicts that Ethernet and TCP/IP will become the foundation protocols for device buses and fieldbuses in the future. In the survey report released on March 19, 1999, VDC (Venture Development Corp.) predicted that in the field of industrial control applications, the world market share of Ethernet will jump from 8.4% in 1998 to 22% in 2003, which is the largest increase among various buses.
At present, some international organizations in the world are engaged in promoting Ethernet into the control field, such as IEEE(Institute of Electrical and Electronics Engineers in the United States) is working to develop new standards for fieldbus and Ethernet communication. This standard will enable the network to see “objects”. IAONO(Industrial Automation Open Networking Alliance) recently reached an agreement with ODVA and IDA Group to jointly advance Ethernet and TCP/IP. On March 17, 2000, ODVA(DeviceNet Vendor Association) released an industry standard for the use of Ethernet services on the factory floor. The FF(Fieldbus Foundation) published the final technical specification (FSI1.0) for high-speed Ethernet (100Mb/s) on March 29, 2000. The Industrial Ethernet Association works with ARC, Advisory Group and other units in the United States to carry out research on key technologies of industrial Ethernet. At present, the development of 1000Mb/s Ethernet has entered the practical stage, although its price is still relatively expensive. From the above analysis, Ethernet into the field of industrial control is a development trend that can not be ignored. This paper briefly introduces some recent advances in industrial Ethernet, and discusses the future prospects.