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Industrial Ethernet Book 103

TAepcphlincoaltoiognys Single-pair balanced Ethernet transmission for IoT applications The mega trends in communication technologies, and their impact on associated cabling philosophies, are being influenced and driven in no small way by the emergence of the IoT, Industry 4.0 (I4.0), cloud computing and smart technologies -- ultimately leading to new connector and cabling solutions. ETHERNET IS THE LEADING NETWORK PROTOCOL in LAN applications and is increasingly gaining ground in new areas. At the start of the Ethernet “era” in the early 1980s, coaxial cabling dominated (thick Ethernet – yellow cable, thin or cheap Ethernet), from the 1990s the focus shifted to cabling solutions based on symmetric cabling (twisted pair) and fibre optics. Initially, twisted pair cabling relied on two-pair cables. This utilized a wire pair as a transmission and reception line (100Base-TX). This principle, limited to a transfer rate of 100Mbit/s, still represents the main transfer principle in industry and automation systems technology today and is often achieved using star-quad cable designs. In order to achieve higher transfer rates of 1 Gbit/s and 10 Gbit/s, a transfer technique was selected, which requires four symmetric pairs in connection with 8-pole connectors. Now, let’s discuss the transfer of Ethernet with a single strand pair, in other words, a solution that quite obviously runs contrary to the technical development of Ethernet and its associated cabling. This article deals with the background of these developments, with the technical details and the normative activities as well as the applications for single-pair Ethernet. We consider the performance of new chipsets and discuss the classification of single-pair cabling with respect to existing two and four-pair versions as well as future n-pair cabling. Mega trends in communications The development of new communication technologies and their associated cabling philosophies, are influenced and driven in no small way by the current ICT mega trends, such as IoT, Industry 4.0 (I4.0), cloud computing and smart technologies. This leads to new demand profiles regarding communications technology and the network infrastructure behind it, based on cables and connectors. Demands include: high availability, short access times including distributed data and fast transport of this data from A to B. Secure transfer of large datasets in different application areas up to determinism (real-time transfer and, for example, guaranteed data transfer within a defined timeframe). At the same time, data transfer should remain cost-efficient. For devices, cables and connecting hardware this means they must achieve higher performance, be smaller and stronger as well as possess a high degree of modularity and compatibility (exchangeability and plug-compatibility). These demands can only be fulfilled through innovation, i.e., new development of products with consistent international standardization. Another trend in network technology and cabling is the increasing use of Ethernet protocols in new application areas. This includes many automation protocols and, increasingly, sensor/actuator applications. Numerous traffic and transport platforms such as rail, tram, bus, ship and aircraft, are fitting their fleets with Ethernet. While Ethernet has been successfully employed, in particularly for passenger information systems and for WLAN services for many years now in the methods of transport mentioned above, it remained more or less unused in the private car/truck market for a long time. The automobile industry has now recognized the advantages of Ethernet and started an initiative to develop Ethernet protocols for short-distance transmission routes in vehicles. The solution is called: single-pair Ethernet for transmission distances up to 15 m or 40 m. This Ethernet technology has since been published in the standards (Gigabit Ethernet over single-pair balanced copper cabling) and 802.3bw 100Base-T1 (100 Mbit over singlepair balanced copper cabling). To achieve simultaneous transmission of data and energy, PoDL was also defined under IEEE 802.3bu (Power over Data Lines = a principle suitable for single-pair transmission for remote powering). On the basis of these standards chipsets, devices, cables and connecting hardware are now being designed, developed and produced for integration in private cars. Cabling for private cars focuses on a transmission distance of up to 15 m and, in general, needs to be produced in unshielded form due to weight and spatial constraints. Larger vehicles such as trucks and buses require longer transmission distances of up to 40 m and, due to the associated higher EMC requirements, need to be fully shielded. In fact, the latter single-pair shielded transmission distance also has other “non-automotive” application groups and 30 industrial ethernet book 11.2017 SOURCE: HARTING Overview of co-action of standardization bodies to strengthen cabling guidelines and technology.


Industrial Ethernet Book 103
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