Big data analytics moves right to the edge

14 April 2020

Brendan O’Dowd looks at the implications of the introduction of the IEEE 802.3cg standard for industrial automation and what it might mean for 4-20mA or HART systems.

The ratification in November 2019 of the IEEE 802.3cg standard marked the introduction of a new and dramatically different way for factory operators to connect devices at the edge of the network, freeing them from the restrictions of infrastructure based on the legacy 4-20mA and HART communications interfaces. 

The 802.3cg standard, also known as 10BASE-T1L, is a type of industrial Ethernet networking protocol. It provides a way to break down the barriers between the basic operational devices which perform frontline service in the factory or process plant – the sensors and valves, actuators and control switches – and enterprise data, where the intelligence of the new ‘smart factory’ comes to life. 

10BASE-T1L networking looks set to become an important enabler of the general transformation towards a data- and analytics-driven approach to factory operation. 

As Industry 4.0 implementations become established in every modern factory operation. At its heart is the desire to profit from the exploitation of ‘big data’. New analytics software has begun to transform the way that industry operates and maintains factory equipment and premises. The insights from analytics are often most profound when they uncover patterns in apparently disparate sets of data. 

The more data, and the more types of data, that can be reliably captured from devices in the factory, the more opportunities there will be for software to support advanced functions such as condition monitoring and predictive maintenance. The low data bandwidth of the 4-20mA and HART interfaces and the limited scope for integrating them into enterprise computing infrastructures has traditionally hampered efforts to apply analytics to these legacy end-points. It has also restricted the amount of power that can be supplied to an end-point, and the scope to manage the device’s operation remotely. 

10BASE-T1L connectivity promises to extend the productivity and efficiency benefits that can be derived from that data to the remotest corners of factories and process plants where sensors and other end-points operate today out of reach of the enterprise network. 

The case for installing 10BASE-T1L equipment today rests on the set of capabilities provided for in the 802.3cg standard. A 10BASE-T1L connection offers: 
• A maximum data rate of 10Mbits/sec over a cable length of up to 1km.
• Up to 500mW of power to end-points in Zone 0 intrinsically safe applications, enabling the operation of a much wider range of more sophisticated end-points than a 4-20mA or HART system can support. It can also supply up to 60W of power to non-intrinsically safe applications, depending on the cabling.
• Potential to reuse existing, installed single twisted-pair cabling.
• Rich device management options, including the supply of diagnostic data from the connected device, and the provision of software updates to it.
• An IP (Internet Protocol) address for every node, extending ‘Internet of Things’ capability to the edge of the factory network. An IP address enables a node to be not only monitored but also managed remotely. 
• Integration with enterprise network infrastructure. 

From a hardware standpoint, implementation of 10BASE-T1L equipment is normally straightforward because the physical medium for its communications is single twisted-pair cable. This might even be the same wiring which already carries 4-20mA or HART communications. The 802.3cg standard also supports installation in hazardous (explosion-proof) environments. 

It is likely that early implementations of 10BASE-T1L will be of hybrid equipment which supports both the legacy interface, such as 4-20mA, and the new industrial Ethernet protocol. 

Making it a success
Two critical factors will determine whether a 10BASE-T1L project is successful – A focus on data and network security.

Once engaged in the operational details of a 10BASE-T1L roll-out, engineers can easily lose sight of the reason for it: to lift the veil on the operation of end-points such as sensors, and feed rich streams of data from them to enterprise-level data analytics engines. 

It follows that the biggest risk to the success of a 10BASE-T1L project is not at the end-points themselves, or at the physical infrastructure: the problem is most often at the back end, when inadequate provision is made for handling and using the data sets coming from the newly connected end-points. 

So, industrial engineers embarking on a 10BASE-T1L installation should keep these questions in mind: 
• What types of insights do I plan to derive from the data that will be acquired from sensors and other end-points? 
• How will the data be integrated into enterprise-level control systems? Is the format of the data from end-points compatible, or does it need translation? 
• How will insights from data analytics lead to process or system improvements? 

The second crucial issue relates to security. The nature of the threat to end-points changes dramatically as soon as they are connected via a 10BASE-T1L network. Before, when connected via 4-20mA, the only way that an end-point could be ‘hacked’ was through physical interference with the device itself or the wires connected to it. A 4-20mA connection is immune to network-borne threats. 

The superior connectivity provided by the 802.3cg standard – including an IP address for every node – makes every end-point vulnerable to remote attack via the enterprise network. The inherent, physical firewall which isolates 4-20mA or HART end-points from the network disappears as soon as the factory installs 10BASE-T1L. 

This means that individual nodes and the network infrastructure itself have to be secured through the implementation of software technologies such as: 
• Secure authentication of devices via encrypted device IDs.
• Encryption of data transmissions.
• Firewalls to bar outside entities from gaining access to secure devices. 

Learning lessons 
Following the ratification of the 802.3cg standard, the development of 10BASE-T1L-compatible components and equipment has been accelerating. For its part, Analog Devices (ADI) has been working with industrial equipment manufacturers to ensure that they are able to follow their roadmaps for the introduction of systems that support 10BASE-T1L networking. The expectation in the industry is that products offering 10BASE-T1L capability will be released to the market by mid-2021. 

ADI’s experience in supporting customers’ implementations of new technology will help make these 10BASE-T1L product introductions successful. The structure of its Industrial Automation division supports technology implementation marrying technical expertise with market insight to produce the right outcome for the customer. In the case of 10BASE-T1L, this approach will encompass the provision of physical layer products and support for the full communications stack. It also takes account of the long commercial lifetimes of industrial products, backed by a roadmap which forecasts continuous production with compatible 10BASE-T1L products for decades to meet the expectations of industrial customers. 

The rapid development of 10BASE-T1L components is enabling industrial equipment manufacturers to start to develop new industrial Ethernet-enabled products. Backed by a consortium of industrial companies which has supported the standard development process, 10BASE-T1L technology looks set to supplant the 4-20mA and HART interfaces and accelerate the adoption of Industry 4.0. 

Brendan O’Dowd is general manager, Industrial Automation at Analog Devices.

More about the IEEE 802.3cg standard 
The IEEE 802.3cg standard for 10BASE-T1L enables 10 Mbps communication and power up to 1km over a single twisted pair cable. It is expected that this technology will replace traditional 4 mA to 20 mA or bipolar analogue voltage communications that proliferate within field devices today. 10BASE-T1L provides up to 500 mW of power in intrinsically safe applications and up to 60 W (cable dependent) in non-intrinsically safe applications. The standards provide unified communication and power protocols, with a common networking infrastructure for edge nodes. 

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