July/August 2019

31 www.drivesncontrols.com July/August 2019 COMMUNICATIONS n The IEEE standard also envisages carrying up to 13.6W of power on the twisted-pair cables – enough to power most sensors and other IoT devices likely to be connected to such cables. This capability is known as power- over-data-line, or PoDL. Alongside work on the Ethernet protocols, an IEC subcommittee (SC 46C) has also been working on four new standards for balanced, shielded SPE cables, including: n Cables for transmission speeds of up to 600MHz over distances of up to 40m. There are two versions: one for permanent installations (IEC 61156-11); the other for flexible installations (IEC 61156-1). n Cables for transmission speeds of up to 20MHz over distances of up to 1km. Here too, there are versions for permanent installation (IEC 61156-13) and for flexible installation (IEC 61156-14). Supporting cast Work is also going on to develop the many other items that will be needed to support the single-pair technology, such as connectors, switches and communications cards. The big public push for industrial SPE began at this year’s Hannover Fair where several exhibitors were showing versions of components including connectors and cables. Harting, for example, was demonstrating video being transmitted from two camera systems via an SPE switch and a media converter. “Single-pair Ethernet represents more than just a new interface – it is a totally new approach and provides new options for Ethernet communications,”says Harting Electronics’product manager for device connectivity, Matthias Fritsche.“A huge new ecosystem of connectors, sockets, cables, Ethernet chips, transmitters, protocols, test devices, standards, markets and fields of application, now has to be designed.” Harting has proposed an SPE connector interface that it hopes will become an industry norm. The interface, designed for use in tough industrial environments, is due to be published as an IEC standard (IEC 63171-6) early next year. Cabling standards are currently being updated for SPE in the form of amendments to the ISO/IEC 11801 and EN 50173 series. By referring to component standards (such as the plug connectors defined in IEC 63171-6), they will ensure that the devices and cabling are compatible. For building automation applications, the US networking infrastructure giant CommScope has been developing an alternative interface, defined in IEC 63171-1. Partnerships As well as developing technologies and standards, Harting has also formed partnerships with the Japanese connector supplier Hirose Electric and the sensor and connector manufacturer, TE Connectivity, to help promote the SPE concept, especially for industrial IoT applications. Harting has also been working with other suppliers. At Hannover, Lütze, Murrelektronik, Indel and EKF Hammwere all showing SPE- compatible components, including cable assemblies, I/O controls, a five-port switch and a 1000Base-T1 communications card. Also at Hannover, another technology partnership was announced – this time involving Phoenix Contact, Weidmüller, Reichle & Massari (R&M), Belden and Fluke Networks, who are developing mutually compatible components for single-pair Ethernet. They are all supporting the pin connector patterns added to IEC 63171-5 (which covers IP67 protection for industrial environments) and IEC 63171-2 (IP20 for office environments). These define pin connector patterns for single- and four-pair data transmission in SPE applications. The companies are pooling their technological expertise to ensure a standardised infrastructure for devices, connectors, cables, and measurement technology. “Single-pair Ethernet is one of the megatrends of industrial data transmission,” explains Torsten Janwlecke, president of Phoenix’s device connectors business. He predicts that SPE’s reduced cabling requirements will bring“completely new areas of application into focus”. SPE is environment-independent, allowing field devices, sensors, and actuators to be incorporated easily into existing Ethernet environments, without needing extra gateways or interfaces.“As opposed to fieldbus protocols, Ethernet is penetrating into every level of automation,”says Janwlecke.“It is more consistent, more efficient, and more cost- effective than fieldbus systems.” “Single-pair Ethernet means a reduction in the amount of work for systems manufacturers,”adds Jörg Scheer, director of Weidmüller’s Device & Field Connectivity Division.“Compared to four-pair Ethernet, installation is easier and enables a noticeable reduction in space and weight.” The emergence of SPE could tie in with other developments in factory automation. For example, in a recent White Paper, the cable- make Belden suggested that combining SPE with Time Sensitive Networking (TSN) and Power over Data Lines (PoDL) could help to deliver end-to-end Ethernet networking from sensors to the cloud. According to the paper, SPE will deliver“one cable and one network type that any sensor or actuator can get power from, and any sensor or actuator can talk to”. So does the emergence of single-pair Ethernet spell the end for the familiar multicore cables and RJ-45 connectors? Certainly not in the short term, and there will probably always be applications where the greater capabilities of the multicore cables will be needed. Thanks to the standardised interfaces, the single- and four-pair cables can be combined with each other, in a similar way to IP20 and IP6x systems. “We consider SPE to be the ideal approach to enhancing existing Ethernet-based network structures in order to increase the density of the existing connection points,” says Matthias Gerber, market manager for LAN cabling at R&M. “This makes it absolutely necessary to define the interplay between SPE and existing RJ-45 cabling systems in the standardisation committees that are responsible for this.” It seems likely that, in the coming years, single-pair Ethernet will change the way that we install communications systems in our factories. “Thanks to digitalisation, intelligent networking is increasing in every aspect of life,” points out Weidmüller’s Jörg Scheer. “Consistent data transmission is also becoming ever more relevant in the industrial environment.”Ethernet cabling is already replacing many traditional fieldbus systems, but he predicts that, with the emergence of single-pair Ethernet,“throughout the world, users will be able to construct efficient network and cabling structures, from the sensors, through the control and company level, right through to the cloud, all based on standardised interfaces.” n SPE connectors are being designed for a variety of applications (Photo: Phoenix Contact)

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