SPE brings IT and automation hand in hand. This article comes from the IIoT and Industry 4.0 e-books.
The Internet of Things (IoT) describes the networking of virtual and real physical objects to use information and communication technologies to make them work together. The objects in our daily lives have acquired digital skills. Therefore, these physical objects can also participate in digital networks. This process also occurs in industrial applications, and it is called the Industrial Internet of Things (IIoT). More and more industrial components are also becoming smart and intelligent participants. These connections are no longer limited to the company's internal network, and devices are becoming part of the Internet. The increase in data collection, evaluation, and use requires a more powerful infrastructure. At the same time, it is expected that this infrastructure will take up less space and use fewer resources. Efficiency is the key word here, because as bandwidth requirements continue to increase, more and more sensors become network participants. New technology is needed. In the automation world, the term "automation island" is used to refer to the entire range of independent and proprietary (but analog) networks that dominate the field level. This classic system split between Ethernet/Internet and analog fieldbus systems should now be broken and eliminated. The goal is to extend Ethernet from the cloud to every sensor. Each sensor will be smart and be able to be evaluated individually-therefore an important step on the road to IIoT. However, proper infrastructure is still missing. Current networks are based on two or four pairs of cables and connectors. Considering the sheer number of sensors and actuators that must be connected in the field, this traditional infrastructure is huge and expensive. For some reason, bus cables are designed to save space and economy. The solution for high-performance Ethernet infrastructure is from the cloud to the sensor: this is based on a single-pair twisted copper wire: single-pair Ethernet (SPE).
From cloud to sensor: This is a statement that has been heard more frequently in the automation environment recently. This statement is usually related to megatrends such as IIoT and Industry 4.0 (I4.0). It refers to Ethernet-based continuous communication based on TCP/IP, and currently mainly covers the distribution level from cloud applications to manufacturing. In the past there was a classic interruption in the communication system between the Ethernet and the bus system, but modern components now only need to use a twisted pair to bring fast Ethernet (up to 1 GBit/s) for the smallest applications. Therefore, SPE realizes the consistent use of TCP/IP for the first time. This promotes the development of new devices and application areas, especially sensor/actuator networks. Sensors become "smart" and become part of the entire network. This speeds up parameterization, initialization and programming. When SPE is used—whether it is using a simple state sensor or a modern vision system composed of high-resolution cameras—the Internet of Things becomes a reality and the field level becomes smart.
After the automotive industry that needs to replace the CAN bus determined this new TCP/IP-based transmission method, the IEEE 802.3 working group released the first SPE standard, which is the standard 100BASE-T1 in Article 96 of IEEE 802.3bw-2015. However, autonomous or semi-autonomous driving requires a higher data rate. Therefore, after the first 100Mbit/s SPE standard, the gigabit version soon appeared. Ethernet technology based on IEEE 802.3bp 1000BASE-T1 is now on the market, using only a pair of copper wires to provide a transmission speed of 1 Gbit/s. IEEE issued a standard of up to 10 Gbit/s (IEEE 802.3ch) in 2021, which is necessary for high-resolution sensors and video transmission. Only the 10 Mbit/s (IEEE 802.3cg) standard was released in February 2020. This standard is very relevant to many industry sectors, because it allows transmission distances of up to 1,000 meters, so it can replace almost all fieldbuses. Another working group was established in March 2019 to handle transmission rates above 10 Gbit/s. Their goals are 25 Gbit/s and 50 Gbit/s. These high data rates are technologies required for autonomous driving and new regional computer architectures in vehicles. SPE is the ideal technology to achieve this goal.
The production and automation industry has similar problems with the automotive industry because it requires an integrated industry, which means the integration of tools and workpieces at the field level (sensor/actuator network) in automated production. It requires a network strategy that can be used universally, and at the same time it can continue well in the future. In other words, non-proprietary IT solutions are required and provide usability and security standards common in the industry. SPE is the correct technology to solve this problem. It provides many advantages:
End-to-end TCP/IP communication as an alternative to a proprietary bus or power interface
High security and 100% availability
A huge range from a few meters to more than 1000 meters
Minimum space required for cables and distributors
Use the data cable to supply power to the terminal device and the sensor at the same time
No need for rechargeable and non-rechargeable batteries, which is an important environmental consideration.
Reduce costs through better operational reliability
Therefore, SPE is a technology that eliminates most of the limitations of wired communications. Compared with other technologies (such as wireless), it also compensates for the shortcomings of cables-based on the type of application considered here. In short, SPE highlights the advantages of copper optical fiber as a transmission medium. Wireless communication is also facing new competition.
Like multiple pairs of wiring, SPE remote power supply also has a new standard, similar to Power over Ethernet (PoE); it is called Power over Data Line (PoDL) (IEEE 802.3bu). This combination of data and power using very small plug-in connectors and single-pair cables helps support the trend toward miniaturization, higher data rates, and modularity of more complex systems. These are the prerequisites for the rapid development of off-vehicle SPE applications such as industry, smart cities, and buildings. Copper Ethernet over 1000 meters? SPE technology has achieved the same performance as today's main "Many Pair Ethernet" (MPE) in a short period of time. Currently, the only limitation is the limited range of 100 Mbit/s and Gigabit SPE (15 m and 40 m respectively), which are caused by the requirements of the main target groups in the automotive industry. Experts agree that longer transmission lengths can also be achieved. The diagram shows the technically possible extended transmission length. However, for these extensions of the SPE standard covered by IEEE 802.3, especially for the semiconductor industry to invest in the development of these new chipsets, it is necessary to define new target applications and appropriate market potential. This requires the open cooperation of all stakeholders to expand the scope of SPE. The first IEEE 802.3 presentation has been published and has been well received. Further supporters of these target standards are very welcome.
There is still a long way to go before the SPE infrastructure and its associated potential are firmly established. Currently, several solutions and different standards are being discussed on the market, with special attention to the SPE interface. Users are now correctly asking whether manufacturers will develop consistent and compatible solutions based on uniform standards, or whether there will be multiple solutions and incompatible mating surfaces. Therefore, it is necessary to carefully study the cooperation of various standards committees and their work related to Ethernet communications. ISO/IEC SC25 WG3: ISO/IEC JTC 1/SC 25/WG 3 plays a central role in standardization. This is the place to create and maintain a cabling standard that complies with ISO/IEC 11801. IEC SC46C: Wiring Component Committee: Copper Data Cable IEC SC48B: Wiring Component Committee: Connector IEEE 802.3: Cable-based Ethernet Protocol Standard
Within the IEC SC46C Commodity Data Cable Standardization Working Group, the following standards are currently being developed:
IEC 61156-11: SPE data cables up to 600 MHz bandwidth for fixed installations (final release)
IEC 61156-12: SPE data cable with up to 600 MHz bandwidth for flexible installation (CD provided)
IEC 61156-13: SPE data cable with a bandwidth of up to 20 MHz for fixed installations (CD provided)
IEC 61156-14: SPE data cable with up to 20 MHz bandwidth for flexible installation (planned).
More standard projects will be handled in the future, such as higher bandwidth supporting data rates higher than 1 Gbit/s.
HARTING submitted the first draft of the SPE connector standard to SC48B as early as 2016 and published it as IEC 61076-3-125 to the CD file. In 2017, CommScope submitted another SPE mating surface for standardization and decided to create an IEC 63171 series of standards for all SPE connectors. Therefore, the project team PT63171 was established in SC48B and was entrusted to prepare this series of new standards. The standards that have been under development so far will be completed as separate documents and then integrated into this new series of standards as revised editions. The following standard projects are currently underway:
IEC 63171: Basic standard with all necessary specifications and test sequence (CDV available)
IEC 63171-1: CommScope SPE connector based on LC interlock, suitable for the published M1I1C1E1 application
IEC 63171-2: SPE connector for M1I1C1E1 applications released by Reichle & De-Massari
IEC 63171-3: Simon's SPE connector is based on a pair of well-known Tera connectors for M1I1C1E1 applications (withdrawn)
IEC 63171-4: SPE connector from BKS for M1I1C1E1 application (CD available)
IEC 63171-5: Phoenix Contact's SPE connectors are based on IEC 63171-2 mating surfaces for M2I2C2E2 and M3I3C3E3 applications (the second CDV is in preparation)
IEC 63171-6 (formerly IEC 61076-3-125): HARTING and TE Connectivity's SPE connectors have been released since January 23, 2020. The second edition is under development for M2I2C2E2 and M3I3C3E3 applications.
Note: IEC 63171-1 (LC style) and IEC 63171-6 (industrial style) are complete standard documents, including all necessary specifications and test sequences. All standards started after this refer to the basic standard IEC 63171 and only describe the different mechanical versions.
SPE and its standardized connectors have been incorporated into the current wiring standards. Internationally, this mainly applies to the structured cabling standard series conforming to ISO/IEC 11801:2017, and in a similar manner to the CENELEC European series of standards conforming to EN 50173. Here, SPE is included in the industrial wiring in Part 3 Annex (Amendment). The central document for these attachments is ISO/IEC TR 11801-9906, a balanced single-pair cabling channel up to 600 MHz for SPE. The implementation of SPE in the ISO/IEC 11801 document is very important. It is the only standard describing the wiring channel of all necessary parameters related to the specified environment of MICE (length, connection number, bandwidth and complete technical transmission related parameter set, including NEXT, FEXT and shielding attributes), so as to be parallel to this after installation Take measurements. Industrial installation standards will be based on IEC 61918 (IEC SC65C) as the basis for the wiring of automation solutions. It remains to be seen to what extent this will affect the automation profile itself. To be sure, PI (using PROFINET conforming to IEC 61784-5-3) and ODVA (using EtherNet/IP conforming to IEC 61784-5-2) actively participated in the further development and implementation of the SPE standard. Combined with the component standards for connectors and cables, all users of SPE can obtain clear guidance on constructing and testing appropriate transmission paths. For 1 Gbit/s SPE, this cabling was initially limited to a range of 40 m. For the 10 Mbit/s variant, a range of 1000 m and above can be achieved. ANSI/TIA-568.5 and TIA TR-42.7 are preparing more documents related to SPE wiring in the United States, Canada, and Mexico. This was updated as an appendix in the TIA-42 document: TIA-1005-A-3. All these additions are basically the same. These cabling standards provide users with information about the cabling structure, the cabling components that should be used to achieve performance specifications, and the limits of test cabling. Therefore, they are the most important tools for setting up and debugging SPE cabling systems. They also ensure compatibility between equipment and cables by providing references to component standards (for example, connectors that comply with IEC 63171-6). This compatibility is a basic prerequisite for the normal operation of SPE-based networks and connections, and is therefore the foundation of IoT/IIoT. In theory, wiring components other than those specified in ISO/IEC 11801-3 Amendment 1 can be used. However, these will no longer comply with the standard, and there will be a risk of incompatibility and loss of functionality. To this end, in early 2018, ISO/IEC JTC 1/SC 25/WG 3 and TIA-42 launched an international selection process to define a unified interface. These two selection processes were jointly initiated by IEEE 802.3. IEEE 802.3 requires ISO/IEC and TIA recommends SPE MDI (SPE Device Interface). Expert groups from more than 20 countries participated in the selection. During this selection process, two connector matching configuration files appeared as the first choice:
For building wiring, the mating surface complies with IEC 63171-1. The mating surface is based on CommScope's proposal.
For industrial and industrial adjacent applications (M2I2C2E2 and M3I3C3E3), the mating surface complies with IEC 63171-6 (previously IEC 61076-3-125). The mating surface is based on the recommendations made by HARTING T1 Industrial.
The selection process of TIA-42 confirmed the results of ISO/IEC, so there is an important consensus on the SPE interface around the world. These selected mating surfaces have now been incorporated into the corresponding international wiring standards. IEEE 802.3 also designates these SPE interfaces as recommended media-related interfaces (MDI) in IEEE 802.3cg. This is necessary for large-scale use. Therefore, it is also necessary to successfully sell SPE technology and consistent compatibility of equipment, cables and connectors in different types of applications. This provides planning security for all market participants. Please note that MICE describes the environmental conditions of the installation. It also provides planners and users with valuable information for specifying technical equipment and wiring. Describes the requirements for mechanical robustness (M), IPxx class (I), chemical and weather resistance (C), and electromagnetic safety (E). In the broadest sense, M1I1C1E1 describes an environment similar to the interior of an office building. M3I3C3E3 describes a fairly extreme environment, such as those found in industry or outdoors.
Even though the existing four pairs of data cabling and SPE all require twisted pairs, the requirements for cabling and connection technology are quite different. This is especially true for the use of currently available SPE transmission standards and the transmission length required by radio frequency (RF), which is particularly obvious for these required bandwidths.
A pair of wires can achieve high data rates-so why not combine four SPE paths in your existing infrastructure? This idea of using four pairs of cables for SPE through "cable sharing" is very simple. This is possible for special situations, but it has no real meaning in terms of technology and economy. On the one hand, compared with MPE, SPE cabling requires higher bandwidth, especially crosstalk. In addition, compared with the MPE with a transmission length of 100 meters, the transmission length of SPE for shielded cables under 1000BASE-T1 is only 40 meters so far. For this migration scenario, the user must check each path of the installed SPE cabling. Therefore, the actual economic feasibility of this type of use strategy is questionable. For example, for installed Cat. The 6A wiring must meet the qualification of 1000BASE-T1, the transmission length must not exceed 40 meters, and the corresponding radio frequency parameters must meet the conditions of up to 600MHz. If all of these are perfectly matched, then you can transmit 1 Gbit/s four times through SPE, even if this Cat. 6A cabling path can still support 10 Gbit/s MPE.
Each connector type is inseparable from a specific application. Of course, international standardization has been achieved. Well-known examples are RJ45 connectors for Ethernet and simple HDMI or DVI connectors for video transmission. Therefore, a standardized interface connector is needed to successfully launch new network technologies (such as SPE) in the market. This is because only by using standardized interfaces can it be possible to network various devices in a unified data network. The design of the SPE connector (according to IEC 36171-6) is based on the specifications of the relevant IEE 802.3 standard and other market requirements.
A differential voltage signal with a nominal voltage of ±1 V is usually used for pure Ethernet transmission. However, when determining the nominal voltage of the SPE connector, the parallel use of the two wires of the remote power supply must also be considered. The method used in SPE for this is to supply power through the data line; it is standardized according to IEEE 802.3bu. Similar to PoE, the maximum rated voltage is 48 VDC, so the maximum supply voltage to the power supply equipment (PSE) is 60 VDC. Compared with PoE, PoDL defines additional 12 V and 24 VDC typical on-board voltages for vehicle insulation voltage. Although the IEEE 80.3 SPE standard does not define clear specifications for the insulation requirements related to the largest user group in the automobile. Normal applications in industrial wiring have the same requirements as four pairs of Ethernet with 1.5 kV (rms) contact to the shield and 1.0 kV (rms) contact to contact (see section 126.5. 1 IEEE 802.3cr). Rated current When determining the rated current, the PoDL requirements are also decisive. In the current standard, Table 104-1 IEEE 802.3bu specifies the maximum feed-in power as 63.3 W, which corresponds to the maximum power supply of the powered device of 50 W. This results in a minimum allowable value of 1.36 A supply voltage at 48 V. However, a rated current of 4 A DC has been selected to maintain a sustainable interference level in the future. Background: According to the National Electrical Code (NEC) of the North American market, the maximum power of NEC Class 2 equipment is limited to 100 W; this is also the maximum remote power supply of the PoE standard IEEE 802.3bt. This means that future PoDL expansion will remain below 100 W, and the 24 V power supply voltage used in industrial automation will result in a rounded maximum rated current of 4 A.
In order to transmit data, SPE uses a full-duplex connection on a differential pair with an impedance of 100 ohms. In order to achieve lower interference sensitivity (especially for electric vehicles), SPE chose a lower code, PAM3 is up to 1000BASE-T1, and PAM4 is used for 2.5/5/10GBASE-T1. Compared with the multi-pair Ethernet standard, this greatly increases bandwidth requirements. For example, IEEE 802.3ch for multi-gigabit SPE up to 4 GHz in 10GBASE-T1 (compared to only 500 MHz 10GBASE-T) is currently under discussion. Therefore, the RF requirements for cables and connection technologies are getting higher and higher, and a very symmetrical connector design is required to reliably meet these more stringent RF requirements. For this reason, the contacts of the T1 industrial connector are symmetrically arranged in a completely enclosed shielded shell. The coupling capacitance and inductance of the two conductors to the shielding layer or printed circuit board are the same. No interference to differential data transmission. This means that the signal paths in the two conductor paths are the same, and the difference in signal propagation time is avoided.
The purpose of the SPE interface design is to consider all the electrical parameters that have been explained above, and to leave enough reserves for future higher bandwidth, remote power supply (PoDL) requirements, and various housing designs that have been accepted and widely used. market. Multiple factors are important: the balance between the market's demand for miniaturized interfaces and high robustness, as well as good handling and well-designed termination areas to match the wire and cable diameters to be used. Following these design goals, 0.5 mm contact gap and 2.8 mm contact gap were selected for the contact system. The contact spacing matches the cross section of the cable to be connected. For the short transmission distance of 100BASE-T1 and 1000BASE-T1, AWG 26 or AWG 22 conductors with a core diameter of approximately 1 mm or 1.6 mm can be used. However, for the longer distance 10BASE-T1L 1000 m, AWG 16/18 conductors are required, with a typical core diameter of about 2 mm; therefore, a contact distance of 2.8 mm is the best. According to the IEEE 802.3 standard, longer distances can only be achieved by using shielded transmission paths. Therefore, in order to ensure safe transmission even in harsh industrial environments, shielding design has been adopted. At the same time, these shielding plates also provide a powerful mechanical interlock for the IP 20 version. The metal latch lever eliminates the problem of damage to the latch mechanism-this is a common criticism of RJ45. M8 and M12 circular connectors have established their applications in industrial applications. Therefore, the M8 structure type of the new SPE mating surface adds threaded, snap-in and push-pull interlocks, making them a unified "data container". The M12 design with screws and push-pull interlock has also been standardized to accommodate the large cable cross-section of the 1000-meter 10BASE-T1L channel. This means that all designs use the same mating surface, and the IP20 connector can also be connected to the IP65/67 interface for parameter configuration or testing. The use of the widely accepted M8/M12 type ensures good market acceptance, while also reducing the necessary investment costs, because many suppliers have already provided corresponding housing designs. The use of the same sockets and plug-in connector inserts ("data containers") in all construction types ensures that all product series have uniform technical characteristics. This makes it easier to implement cost-effective production through economies of scale. Therefore, the SPE interface that complies with IEC 63171-6 provides an internationally standardized mating surface that can best support the future use of SPE in industrial applications. By using this standardized SPE data container, this IEC 63171-6 mating surface can also be easily integrated into other designs, such as the connector system with internal M12 push-pull interlocks currently being developed as a new standard project.
Industrial Ethernet is becoming more and more common in automation and I4.0 applications. More and more devices and solutions from all walks of life are becoming "smart"-for this, they need a suitable Ethernet infrastructure. The SPE ecosystem shows us how technologies, standards, infrastructure components, equipment, and test equipment can logically establish and support each other. They ultimately provide a solid foundation for the digitization of many different markets. This is why HARTING is actively working in the field of standardization and developing infrastructure suitable for industrial use. HARTING is now actively supporting equipment manufacturers to implement SPE. All partners hope to provide building blocks for the SPE ecosystem. They see themselves as partners of the Industrial Ethernet User Group, because SPE can provide new infrastructure for these protocols (such as PROFINET), which will enable IP-based communications all the way to the field level. As the slogan promises: "SPE-IIoT infrastructure." This means that SPE will not only support many applications in a more efficient and environmentally friendly way, but SPE will also support many new applications. In addition to the current main discussion on digital technology, the social challenges and impacts of digitalization on our democratic society must also be discussed in the whole society. These challenges and impacts only took shape at the beginning of the first industrial revolution. Ulrich Sendler gave a detailed overview of the development of industry, technology, and society in the book "Digital Networks: Mankind in Turbulence-The Road to a New World View" published in 2018. This is a book worth reading, and offers many suggestions on the steps needed to ensure that digitization succeeds in society and serves the well-being of mankind.
New application areas such as autonomous driving, the Internet of Things, and the Industrial Internet of Things require new and more powerful network technologies. SPE is such a technology. Compared with wireless solutions, the ability to simultaneously power devices and provide data through only one connection is a huge advantage. The remote power supply through PoDL makes batteries and accumulators redundant-this is a major advantage of environmental compatibility and sustainability. The cable-based transmission method has an additional advantage, that is, there are no regulatory restrictions on the available frequency range, so there is no need to incur licensing fees for the necessary frequency bands. Since frequency bands are not uniformly allocated (even on an international scale), devices with radio interfaces must always adapt to different market needs. This is not necessary for cable-based transmission methods. Therefore, a unified device that can be used on a global scale can be developed. Together with the Time Sensitive Network (TSN) standard developed in IEEE 802.1, Ethernet technology and all necessary mechanisms are being expanded to achieve deterministic data communication-a prerequisite for all real-time applications. Therefore, SPE is the perfect infrastructure solution and "facilitator" for the Internet of Things and Industrial Internet of Things, making it an important part of the integration industry. In order for SPE to fully realize this potential in the ecosystem, partners from different industries must work together to make this vision possible. The first is the joint international standardization of IEEE 802, ISO/IEC and TIA. It continues to develop and produce the necessary components, starting with semiconductors, magnetic components, connector/cable components and measurement technology. Only when standards and components are available (at least in the initial sample quantity), users can equip their many possible devices with SPE transmission technology and open up a wide range of new applications. This article comes from the IIoT and Industry 4.0 e-books.
Matthias Fritsche is HARTING's product manager and Ethernet connection expert. He pays close attention to the latest trends and developments in HARTING Industrial Ethernet communications. He is also a member of various standards committees and actively promotes standards and specifications for users. Fritsche has accompanied and promoted the topic of single-pair Ethernet for many years, and regards it as the future infrastructure of industrial networks. Jonas Diekmann is the technical editor of HARTING Technology Group, responsible for the public relations, news, marketing and content management of the electronic department. Over the years, the co-authors have also been working on the topic of SPE and have brought customers and readers closer to the topic through technical articles that emphasize the future of Gbit Ethernet. Rainer Schmidt is the industrial wiring business development manager of the German HARTING Technology Group. Schmidt actively participates in international standardization, such as IEC SC65C (IEC61918, IEC61784-5 series), Cenelec TC215 (EN50173 and 50174 series) and TIA TR-42. Schmidt is the chairman of ISA/IEC JTC 1/SC25 and a member of SC 25/WG 3 (ISO/IEC11801 series).
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