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Industrial Ethernet Book 103

Technology 32 industrial ethernet book 11.2017 Technology edition) it will also be determined in which application-specific parts an addition with single-pair shielded balanced cabling is technically and economically feasible. Initial consideration seems to suggest this is so for ISO/IEC 11801-3 (industrial applications) and ISO/IEC 11801-6 (building automation). Publication is expected in 2018. At the same time, the cabling specifications allow the requirements for the components, cables and connectors to be derived. This is performed for cables in the IEC SC46C standards committee and for connectors in the IEC SC48B standards committee (SC = subcommittee). Cables for 1 Gbs over one pair These international standards titles describe cables that are suitable for transferring 1 Gbit/s over a balanced pair. Application areas include office, home and industry. The use of 4-pair data cables should also be possible, which are capable of operating 4 single-pair transmission channels. This feature is also known as so-called “cable sharing”. The transmission parameters should be defined for a frequency of up to 600 MHz. This international standard should be published by 2018/2019. IEC 61076-3-125: “Connectors for electronic equipment - Product requirements - Detail specification for 2-way, free and fixed connectors for data transmission up to 600MHz with current carrying capacity Following the application areas and performance of the single-pair cables, the two-pole connectors are being standardised up to min. 600 MHz. Standardisation of the connector means that the mated interface will be fully defined. Definition of the interface ensures plug compatibility and guarantees that products from different manufacturers can be used. It is expected that various designs of single-pair connectors will then be available in safety class IP20 to IP65/67. The publication of this standard is also scheduled for 2018/2019. Balanced transmission channels The theoretical basis for designing a 40 m channel with single-pair cabling has already been worked out. This means that the interested manufacturers of electronics and cabling have all the necessary information on the development and design of chipsets, cables and connectors at their disposal. The first chipsets are already available on the market. However, a range of new products, which offer optimal support for the individual applications, are still expected. Accordingly, devices fitted with “single-pair Ethernet” are expected within two to three years. There are basically two ways to transmit Ethernet according to 1000Base T1 over a single-pair cabling channel. On the one hand, this protocol can be transferred using existing four-pair cabling according to category 7 / transmission class F (specified up to 600 MHz) or according to category 7A / transmission class FA (specified up to 1000 MHz) according to the relevant qualification and with consideration of the length restriction of 40 m. This opens up the option of “cable sharing”, which allows several single-pair Ethernet services to be transferred using a four-pair cable. On the other hand, and this is generally the case, new single-pair cable and connector products are created to serve new single-pair cabling structures on the basis of single-pair Ethernet. Important points for the design of the cabling components include: • Impedance 100 Ω, bandwidth 600 MHz and the associated fixed parameters, such as insertion loss, return loss, alien cross-talk etc. • Complete shielding to ensur e transmission quality under extreme EMC conditions • Single-pair cable with the smallest possible outer diameter (space and weight savings) for fixed and flexible installation • Two-pole connectors in the smallest possible design form for use in IP20 and IP65/67 environments – mutually compatible plug interfaces. Conclusion and outlook The increasing network requirements driven by the demands of I4.0 and IoT rely on innovative and application-specific solutions. Single-pair Ethernet offers a solution for cable-based communications infrastructure. Particularly for application areas in industry and building management, this represents a smart addition to the communications landscape, which combine Gigabit Ethernet performance, transmission reliability, optimal handling and remote powering as well as space and weight savings. The normative basics have already been defined in IEEE 802.3 Standards for applications within the automotive and non-automotive sectors. For the respective non-automotive applications, the planning orientation incorporated within the international standards of ISO/IEC and IEC is used. The respective standardisation projects have been started. The compact design of the device connectivity and the Ethernet compatibility according to IEEE802.3 offer device development, e.g. within automation as well as sensor and actuator production, a networking concept that represents a simple change from bus- to Ethernet technology. This allows Ethernet to penetrate further into the field level, reduces enormously times for parameterisation, initialisation and programming and expands the range of functions of devices. Single-pair cabling saves space, installation time and costs. At the same time new applications are tapped, which were previously reserved for cable-based infrastructure. After the internet and Ethernet have connected people, computers and machines both in terms of space and time, this is now also happening with objects and things. The backbone of this new technology is provided by, amongst others, single-pair balanced copper cabling. With this it becomes clear that the connection between single-pair Ethernet technology and is more prevalent within the mega trends of IoT and I4.0 than in cloud computing and big data. Single-pair Ethernet represents an important technological progression, but is still only an addition to existing Ethernet technologies that use multi-pair copper cables or fibre optics and will not replace them. Final thoughts Single-pair Ethernet cabling opens up new application areas, such as in industry and represents a useful addition to existing four-pair cabling systems. Therefore, singlepair Ethernet particularly supports trends such as IoT and I4.0. In particular, singlepair Ethernet can provide an important technological basis to the further development of multi-pair cabling within the development of cloud computing. Matthias Fritsche, Product Manager Device at HARTING, Rainer Schmidt, Business Development Manager for HARTING and Yvan Engels, Strategic Market Development / Standardization BU Datacom, LEONI Kerpen GmbH. IP20 and IP67 T1 connector design studies for SPE. SOURCE: HARTING


Industrial Ethernet Book 103
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