“The November 2019 endorsement of the IEEE 802.3cg standard marks the introduction of a radically new way for plant operators to connect devices at the network edge, freeing them from the constraints of infrastructure based on traditional 4 mA to 20 mA and HART® communication interfaces .
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By Brendan O’Dowd, Analog Devices
The November 2019 endorsement of the IEEE 802.3cg standard marks the introduction of a radically new way for plant operators to connect devices at the network edge, freeing them from traditional 4 mA to 20 mA and HART-based®Infrastructure limitations of the communication interface.
The 802.3cg standard, also known as 10BASE-T1L, is an industrial Ethernet network protocol. Through this protocol, it is possible to break down the barriers between the basic operational equipment (sensors, valves, actuators and controls) that perform front-line services in the factory and the enterprise data, bits and byte libraries that enable the intelligence of the new smart factory. 10BASE-T1L networks will be an important enabler of the shift to a data- and analytics-driven factory operating model, a trend known as Industry 4.0.
Does this mean that industrial engineers should be ready to replace 4 mA to 20 mA or HART systems with 10BASE-T1L infrastructure, even though the 802.3cg standard is just being set?
What are the key factors for a successful transition from 4 mA to 20 mA or HART to 10BASE-T1L?
Figure 1. 10BASE-T1L enables big data analytics at the edge of the factory network
Data analytics supports increased productivity and efficiency
Industry 4.0 implementation is sweeping every modern factory operation. At the heart of Industry 4.0 is the desire to profit from big data. New analytical software has begun to change the way industries operate and maintain factory equipment and buildings. Insights from analytics are often most profound when they reveal patterns across distinct datasets.
The more data and types of data that can be reliably obtained from plant equipment, the greater the opportunity for software to support advanced features such as condition monitoring and predictive maintenance. The low data bandwidth of 4 mA to 20 mA and HART interfaces and the limited scope for integrating them into enterprise computing infrastructures prevent engineers from applying analytics to these traditional endpoints. 4 mA to 20 mA and HART technology also limit the amount of power that can be supplied to endpoints and the range of remotely operated devices.
Therefore, the advantages of data obtained by converting existing 4 mA to 20 mA or HART devices to 10BASE-T1L can be used to increase productivity and efficiency. Smart, connected factories are often able to reduce unplanned downtime, reduce energy waste, make better use of equipment and other assets, and deploy people more efficiently. 10BASE-T1L connectivity promises to extend these benefits to all corners of the factory, where sensors and other endpoints operate outside the confines of the enterprise network.
10BASE-T1L: Higher data rates and power output
The situation in which 10BASE-T1L equipment is installed depends on the set of functions provided by the 802.3cg standard. The 10BASE-T1L connection provides the following functions:
・Maximum data rate of 10 Mbps over a cable of up to 1 km.
Provides up to 500 mW of power to endpoints in Zone 0 intrinsically safe applications, enabling operation of a wider range of and more complex endpoints than can be supported by 4 mA to 20 mA or HART systems. It can also deliver up to 60 W to non-intrinsically safe applications, depending on wiring.
• It is possible to reuse existing, installed twisted pair cables.
• Extensive device management options, including providing diagnostic data from connected devices and providing them with software updates.
· Internet Protocol (IP) addresses for each node, extending IoT capabilities to the edge of the factory network. Through the IP address, you can not only monitor the node, but also manage the node remotely.
• Integrate with enterprise network infrastructure.
From a hardware perspective, implementing 10BASE-T1L devices is usually straightforward. This is because the physical medium used for 10BASE-T1L communication is a twisted pair. This might even be the same cable that carries 4 mA to 20 mA or HART communications. The 802.3cg standard supports installation in hazardous (explosion-proof) environments.
Early implementation of 10BASE-T1L is possible on hybrid equipment that supports both legacy interfaces (eg 4 mA to 20 mA) and the new Industrial Ethernet protocol.
Success on 10BASE-T1L
Analog Devices will play an important role in the adoption of Industry 4.0 technologies by many customers. Our experience shows that two key factors will determine the success of a 10BASE-T1L project:
・ Attention to data
・ Network Security
Once attention is paid to the operational details of a 10BASE-T1L implementation, engineers may lose sight of the reason for implementing it, which is to uncover the truth about the operation of endpoints (such as sensors) and feed the rich streams of data from them into enterprise-level data analytics engines.
Therefore, the greatest risk to the success of the 10BASE-T1L project is not the endpoints themselves, but the physical infrastructure; problems often arise in the backend, when the data sets from newly connected endpoints are not sufficiently prepared to process and use them.
Therefore, industrial engineers embarking on a 10BASE-T1L installation should consider these questions:
· What types of insights can I gain from the data I get from sensors and other endpoints?
• How to integrate this data into enterprise-level control systems? Is the format of the data from the endpoint compatible or does it need to be converted?
• How will the insights from data analysis improve the process or system?
The second key issue for engineers to face is security. As long as endpoints are connected through a 10BASE-T1L network, the nature of threats to endpoints changes dramatically. A less sophisticated connection reduces the risk of attack when previously connected via 4 mA to 20 mA.
The excellent connectivity provided by the 802.3cg standard, including the IP address of each node, makes every endpoint vulnerable to remote attacks over the corporate network. As soon as the factory installs 10BASE-T1L, the inherent physical firewall that isolates the 4 mA to 20 mA or HART endpoint from the network disappears.
This means that the individual nodes and the network infrastructure itself must be secured by implementing various techniques such as:
・ Device security authentication by encrypted device ID
・ Data transmission encryption
・ Firewall that prevents external entities from accessing the security device
Figure 2. Using 10BASE-T1L to unlock rich data streams for enterprise-grade data analytics engines
Lessons learned from Industry 4.0 projects
The development of 10BASE-T1L compliant components and devices has been accelerating since the 802.3cg standard was endorsed. On our side, ADI has been working with industrial equipment manufacturers to ensure that they can follow the roadmap to introduce systems that support 10BASE-T1L networks. The industry expects that products offering 10BASE-T1L functionality will be available by mid-2021.
ADI’s extensive experience in supporting customers implementing new technologies will contribute to the successful introduction of these 10BASE-T1L products. The Industrial Automation segment will support the implementation of this technology as it combines technology-focused developers with market-oriented people focused on customer applications. This team-based model combines technical expertise with market insights to bring clients the right direction.
For 10BASE-T1L, this mode will provide the PHY product and support the full communication stack. It also takes into account the long commercial useful life of industrial products, supported by a roadmap that predicts decades of continuous production of 10BASE-T1L compatible products to meet industrial customer expectations.
The rapid development of 10BASE-T1L components by Analog Devices and others will enable industrial equipment manufacturers to begin developing new products that support Industrial Ethernet technology. Backed by a strong consortium of industrial companies supporting the standards development process, 10BASE-T1L technology is expected to replace 4 mA to 20 mA and HART interfaces and accelerate the adoption of Industry 4.0.
Figure 3. ADI Chronous, Scalable Ethernet, Just Right
