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Industrial Ethernet vs Commercial Ethernet
This paper aims at focussing on Industrial Ethernet and the most popularly used protocol PROFINET. It also describes commercial Ethernet and the difference between commercial and industrial Ethernet.
Keywords: Ethernet, Industrial Ethernet, PROFINET, Industrial automation,
Ethernet is widely used protocol in most of the computer networking systems existing today. Along with wide spread commercial applications, Ethernet has also been far spread widely used protocol in industrial automations and real-time applications under the name Industrial Ethernet. In this paper, difference between commercial Ethernet, industrial Ethernet, and widely used industrial Ethernet protocol- PROFINET- are discussed.
Computer networking is now an integral part of massive communications. Networking, thus has become an increasingly pervasive, worldwide reality because of its fast, efficient, reliable and effective results. Ethernet is the topmost popular physical layer LAN technology in use today, with networks traditionally operating within a single building, connecting devices in close proximity. A transmission data rate of upto 10 Mbps is supported by standard Ethernet network. The LAN types include Fast Ethernet, Token Ring, 10 Gigabit Ethernet, Fiber Distributed Data Interface (FDDI), Gigabit Ethernet, Asynchronous Transfer Mode (ATM) and LocalTalk. Some of the important features of Ethernet include speed, cost and ease of installation, making Ethernet an ideal networking technology for most computer users today. On a physical connection being established, network protocols define the standards that allow computers to communicate. This method of accessing the physical network allows multiple protocols to coexist over the network media, and allows the network builder to use common hardware for a variety of protocols. This concept is known as “protocol independence,” which means that devices, which are compatible at the physical and data link layers allow the user to run many different protocols over the same medium. Ethernet supports networking through various topologies which provides user an ease to connect number of devices for interconnection.
III. Evolution of Ethernet
Created at Xerox PARC in early 1970s and ratified by the IEEE as a standard in 1983, Ethernet has become the dominant LAN technology. Even after more than 30 years after its specification, the evolution of Ethernet continues. By 2020, according to the Ethernet Alliance, the technology could have as many as 12 speeds, with six of those speeds approved within the next few years.
Some of the key features of Ethernet include:
3. Hard Quality of Services (QoS)
4. Service Management
5. TDM support
Although Ethernet is widely used for commercial applications, it shows several limitations when used in industrial automation applications. Some among the major drawbacks of Ethernet include:
1. The uncertainty of communication
2. The non-real time of communication
3. Commercial Ethernet does not have high stability and reliability.
4. Security Issues
5. Bus Power supply issues.
These limitations can be overcome using industrial Ethernet.
IV. Industrial Ethernet
There lies a tremendous need for advanced technologies in automated industries, to ensure specific manufacturing data is correctly sent or received. Industrial Ethernet automation technology is able to send data over the network to ensure the intended task is properly completed.
Industrial Ethernet is Ethernet applied to an industrial setting, which often requires more rugged connectors, cables, and better determinism. In order to achieve better determinism, industrial Ethernet uses specialized protocols in conjunction with Ethernet. The more popular industrial Ethernet protocols are PROFINET, EtherNet/IP, EtherCAT, SERCOS III, and POWERLINK. With industrial Ethernet, data transmission rates range from 10 Mbps to1 Gbps.5However, 100 Mbps is the most popular speed used in industrial Ethernet applications.
V. Difference between Industrial Ethernet and Commercial Ethernet
Commercial Ethernet is designed for a base level of use, while industrial Ethernet can be considered for multiple levels and applied to more heavy duty environments. Industrial Ethernet is better suited to handle factory noise, factory process needs, and harsher environments, and is even able to respond better to data collisions at the plant floor. Cables used for interconnection also differ in both commercial and industrial Ethernet technologies. Depending on the application for which Ethernet is used in industry, the cable is designed to handle appropriate load, chemical and temperature resistant, jacketed, etc. Determinism is an important factor when defining Industrial Ethernet and separating it from Ethernet. Standard Ethernet They need packets of data to be sent and received at specific times, and they need a guarantee that data will be delivered each and every time. This is because a loss of data or a delay of data between equipment in an industrial setting can end in disaster like a major flaw in the production process, for instance. This real-time information transfer is often a major deciding factor for a company when it comes to choosing what type of Ethernet solution to deploy. Companies will need to assess their specific needs and determine what Ethernet solution is best for their organization. Ethernet equipment and cabling often must withstand the following environmental conditions:
· Temperature Extremes.
· Chemical Exposure.
· Humidity Levels
· UV Radiation Exposure
· Physical Hazards.
Industrial Ethernet, thus being able to overcome environment adversities, has proved to be a widely used technology in industrial automation as well.
VI. Industry 4.0
Industry 4.0 is the term encompassing “Industrial Internet of Things” (IIoT) along with machine-to-machine (M2M) communication and IPv6, seeks to consolidate the advances in sensors and communications already underway. Within the context of Industry 4.0, industrial production is increasingly associated with cutting-edge communication technology. This enables the economical combination of high piece counts, individual customer desires and high quality. Industrial Ethernet networks use intelligent switching technology which can communicate with control networks. The improved processes and productivity by industrial Ethernet thus attracts majority of the market towards itself.
VII. Industrial Ethernet Protocols
Selecting a most viable Ethernet Standard for the desired industrial application plays a very important role. Standards are published documents that establish specifications and procedures designed to ensure the reliability of the materials, products, methods, and/or services people use every day. Industrial Ethernet manifests in five real-time Industrial Ethernet Protocols: EtherCAT, EtherNet/IP, Powerlink, PROFINET IRT, SERCOS III. Specifically in the context of real-time deterministic fieldbuses, there are three different approaches that have emerged that allow the standard to deliver determinism on an Ethernet-based infrastructure:
i. Standard Software / Standard Ethernet: Based on TCP/IP: Protocols are based on standard TCP/IP layers with real-time mechanisms embedded in the top layer. These solutions usually have a limited performance range.
ii. Open Software/ Standard Ethernet: New standard protocols are implemented on top of standard Ethernet layers. These solutions benefit from Ethernet evolution without further investment. However, to deliver the determinism, the standard must include a proprietary software controller at the OSI Layer 3&4 to reserve time on the network, otherwise latency can occur.
iii. Open Software / Modified Ethernet: These solutions effectively create a new standard to take advantage of the existing Ethernet hardware, but require a new protocol and some hardware that guarantees determinism. The software is published freely and in the public domain. The hardware can be as complex as a special switch or as simple as an ASIC that fits into the slave device.
One of the widely used industrial Ethernet protocol is PROFIINET. The features of PROFINET are as given below.
PROFINET is the standard for industrial networking in automation. It connects devices, systems, and cells, facilitating faster, safer, less costly and higher quality manufacturing. It easily integrates existing systems and equipment while bringing the richness of Ethernet down to the factory floor. Being an Ethernet-based network, PROFINET is easy to cable and install, with many available tools for diagnostics and network management. The modularity of PROFINET systems also permits straightforward upgrades for handling additional automation and enterprise functions that may have previously been assigned to fieldbus or one of its office Ethernet networks. This solution is able to operate in the difficult environments of industry and is capable of delivering the speed and precision required by manufacturing plants. It can also provide additional functions – for example Safety, Energy Management and IT Integration. These can be used in combination with the control and monitoring functions. Some other advantages of working with PROFINET at the IO level are:
· Highly scalable architectures.
· Access to field devices over the network.
· Maintenance and servicing from anywhere (even over the internet).
· Lower costs for production/quality data monitoring
Ethernet is the widely used protocol for commercial applications. It is also the most popular industrial automation communication standard supporting various user friendly features and providing reliable, efficient, fast, reproducible results. Among the five real-time industrial ethernet protocols, PROFINET is widely used because of its user friendly features such as ease of integration, easy upgradations, lower costs, etc.
. Rafael Sánchez, Lampros Raptis, Kostas Vaxevanakis, “Ethernet as a Carrier Grade Technology:Developments and Innovations”,
IEEE Communications Magazine, volume 46, issue 9, September 2008.