Accelerate the transition to Industry 4.0 with Industrial Ethernet connectivity

The Fourth Industrial Revolution is changing the way we make products, thanks to the digitization of manufacturing and processing equipment. We have witnessed the benefits of automation technology over the past few decades, and now advances in data processing, machine learning, and artificial intelligence are further promoting the development of automation systems. Today, automation systems are increasingly connected, enabling data communication, analysis, and interpretation, and enabling auxiliary intelligent decision-making and actions in factory areas. Smart factory initiatives are creating new business value by increasing production, asset utilization, and overall productivity. They use new data streams to achieve flexibility and optimize quality while reducing energy consumption and reducing waste residues. In addition, cloud-connected intelligent systems make manufacturing environments more efficient by supporting mass customization.

The advantage of Industry 4.0 is the ability to make better decisions by making full use of the increasing amount of data. In the entire automation system, the ability to obtain and transmit data in a timely manner depends on the connection network. In order to cope with the growing amount of data, network technology as well as manufacturing process processes and methods must be continuously improved. Smart, interconnected automation environments require digital connection systems, machines, robots, etc. to create and share information. The communication methods used by these machines and the deployed factory communication networks are the core of the enterprise and the key to promoting the realization of Industry 4.0.

Figure 1. Cloud infrastructure.

All sensors and actuators throughout the plant (even remote locations) need to be seamlessly connected, but this is not possible using existing infrastructure. If enterprise-level data is needed to provide actionable insights in the future, the challenge is to find a way to enable this unprecedented amount of data to be transmitted without disrupting the communication network. This raises the question of how to design, build, and deploy an industrial communication network that can meet the needs of today's automation environment and tomorrow's virtual factory.

Why Industrial Ethernet?

Since connectivity is at the core of realizing the vision of Industry 4.0, three conditions must be met for enterprises to truly achieve connectivity. First, higher-level information technology (IT) or enterprise infrastructure must be integrated with the control network of the plant. Second, the various existing networks or production units in the plant must coexist in a collaborative manner to support interoperability. Third, we need to achieve seamless and secure connectivity throughout the process environment, from the process terminal all the way to the enterprise cloud.

To meet these challenges, we need to adopt basic network technologies that support the goals of interoperability, scalability, and coverage. Widely deployed Ethernet technology is the ideal solution. It provides high bandwidth, supports rapid commissioning, and can be widely deployed in the IT infrastructure of all manufacturing environments.

Figure 2. The convergence of two major domains: information technology (IT) and operational technology (OT).

However, given the need for real-time operations, standard Ethernet is not a viable solution for industrial control infrastructure. Operational technology (OT) control networks need to ensure that communication messages are delivered to their intended locations on time. This ensures that the task or process at hand is operating correctly. The TCP/IP protocol used to route traffic does not inherently guarantee this level of deterministic performance. In the same way that standard Ethernet enables file sharing or access to network devices such as printers, Industrial Ethernet allows controllers to access data and send instructions from PLCs to sensors, actuators, and robots throughout the factory floor. The key difference is the impact of delayed or undelivered messages. In non-real-time applications, a slow web page update has little impact, but in a manufacturing environment, it can have a huge impact, from wasted materials to accidental personal injury. For control systems to work properly, messages must be delivered reliably and on time every time.

As a result, Industrial Ethernet has become the technology of choice for control-level operational technology. Seamless connectivity is required not only between IT and higher-level OT networks, but also between the various layers of the factory OT network and the end-node sensors, as shown in Figure 3. Today, connectivity requires the use of complex, power-hungry gateways in the lower layers of the OT network, and converged IT/OT networks in the higher layers of Ethernet. Having an interoperable, factory-wide Ethernet-based automation network eliminates the need for these gateways, thereby simplifying the network itself. In fact, the protocol gateways used to translate and support the upper layers of the OT network are not directly addressable and create isolation in the network. This data isolation limits the ability to share information across the factory. This runs counter to the vision of Industry 4.0 described earlier, where manufacturers wanted to collect telemetry data from the OT side to drive analytics and business processes on the IT side.

Figure 3. Automation system pyramid.

Since determinism in packet delivery and timing ensures that control applications meet mandatory requirements, many vendors have begun to offer real-time protocols suitable for OT networks. This has led to solutions that are deterministic but rely on protocols from each vendor. As a result, a large number of incompatible solutions have emerged, each using a different type of communication protocol running in different manufacturing units and not interoperating with each other. This has led to long-term data isolation or data silos. A solution is needed that allows different manufacturing departments using different protocols to coexist and share the network without degrading control traffic. This solution is time-sensitive networking (TSN) - a vendor-neutral real-time Ethernet standard based on the IEEE 802.1 specification. As the name suggests, TSN is about time. It transforms standard Ethernet communication into communication that provides timing guarantees for mission-critical applications. The standard aims to ensure that information can move from one point to another in a fixed, predictable time. In this way, TSN guarantees timely delivery. In order for communication to be predictable, devices on the network must use the same concept of time. The standard defines a method to transmit specific TSN Ethernet frames according to a schedule while allowing non-TSN frames to be transmitted on a best-effort basis (see Figure 4). In this way, TSN enables real-time and non-real-time traffic to coexist on the same network. Because all devices use the same time, important data can be transmitted with low latency and low jitter at speeds of up to gigabits.

Figure 4. Time-sensitive network characteristics.

The goal is to build a converged network where each protocol can share the wire in a deterministic and reliable way. TSN is a standard toolbox that provides the required determinism. It represents a transition to a reliable and standardized connectivity architecture that eliminates data isolation through dedicated fieldbuses. This network convergence, in turn, drives the generation of more data by increasing the scalability of the network itself, in bandwidths ranging from 10 Mbps to 1 Gbps and beyond.

It is likely that TSN will be adopted throughout new facilities, but will be phased in to parts of existing plants. For manufacturers of field devices, this means that in the near future, traditional Industrial Ethernet solutions will need to be supported alongside TSN.

Extension to process terminal

Our final, and perhaps most impactful, change is the ability to enable seamless connectivity from the end node to the enterprise cloud in process control applications, as shown in Figure 5. Until now, connectivity to the end has been limited to existing 4 mA to 20 mA or available fieldbus technologies. In many implementations, these are hardwired point-to-point connections, limiting the flexibility to grow and expand the network over time. These non-Ethernet-based field communications face several challenges. First, very limited bandwidth (e.g., 1.2 kbps for HART® with 4 mA to 20 mA) limits the amount and speed of information flow. Second, the limited power input of the instrument itself limits the functionality of the instrument. Finally, the overhead of gateways at the control and IT levels is unsustainable. There is also the challenge of operating in a Zone 0 intrinsically safe environment and trying to leverage existing cable networks to support faster and cheaper commissioning.

Figure 5. Seamless connection from terminal to cloud.

All of this is driving the development of the IEEE 802.3cg-2019™ standard for 10BASE-T1L full-duplex communications. This standard, which was recently ratified, defines specifications for 10 Mbps full-duplex communications over single twisted pair cables up to 1 km long with power. Data will now be available in sensors and transmitted in OT and IT infrastructures as Ethernet packets. No conversion is required (which causes latency, consumes power, and incurs cost overhead). Existing network architectures will change (as shown in Figure 5), with remote I/O units converted to Ethernet field switches. Ethernet commands can now be transmitted between controllers and field instruments via 10BASE-T1L multi-port field switches. Insights gained at field nodes can then be transmitted as Ethernet packets (with higher bandwidth) over the field switching network to the PLC/DCS and ultimately to the cloud.

There are several distinct advantages that drive the transition from traditional fieldbuses to Industrial Ethernet. First, existing cabling infrastructure can be reused (up to 1 km), simplifying deployment and reducing retrofit costs. Second, the available power delivered through the cable to the instrument itself, previously limited to 36 mW (optimal when deployed with 4 mA to 20 mA), can now reach 60 W (depending on the cable) or 500 mW in Zone 0 (intrinsically safe applications). The additional available power now supports instrumentation with terminal intelligence and more features. Combined with the currently available 10 Mbit uplink speed, it is expected that more insights can be provided, thereby achieving ROI efficiency for Industry 4.0.

What technologies are currently available?

A new powerful low-latency, low-power physical layer technology needs to be combined with a scalable switch architecture to support the development of automation networks. ADI has always been at the forefront of the development of Industrial Ethernet. We use our rich automation domain expertise and advanced technologies to continuously develop a broad portfolio of solutions to ensure reliable delivery of time-critical data in industrial applications, seamless connectivity and efficient operation. ADI's Chronous™ scalable Ethernet solution portfolio includes physical layer devices (PHY), embedded switches, and complete platform solutions with multi-protocol software. These are fully tested and verified to speed up product launch.

Figure 6. ADI Chronous—industry-leading Industrial Ethernet solutions.

Figure 7. Providing trusted data to ensure network security.

Key solutions include:

ADIN1200, the industry-leading 10 Mbps/100 Mbps Industrial Ethernet physical layer device, offers an enhanced feature set and proven reliability.

ADIN1300, the industry-leading low-latency, low-power Gigabit physical layer device, has proven reliability and is suitable for demanding application environments.

fido5200/fido5100, real-time embedded dual-port multiprotocol switch, supports multiple available TSN features. New TSN features can be enabled through available firmware updates. Multiprotocol software updates are also supported and are available through the ADI Chronous Developer Portal.

ADI Chronous is a proven, scalable, and complete Ethernet solution that simplifies system design and reduces development time. It is a perfect scalable Ethernet solution.

To support this transition and provide network connectivity for traditional field devices, ADI has developed a new technology called software configurable I/O (AD74413R). This will facilitate the development of field configurable remote I/O units to achieve the convergence of traditional instrumentation with high-level Ethernet networks.

How safe is it?

Ethernet has security vulnerabilities, and security is one of the key issues affecting the popularization of Industry 4.0 technology. If an open information flow is created between OT and IT and across the entire enterprise from terminal to cloud, security vulnerabilities can have a devastating impact.

Security should be a fundamental risk management consideration when planning an Industry 4.0 strategy. However, building security into today’s increasingly complex networks is not easy; a multi-layered approach is required to ensure that the system itself is secure—whether it is the end device, controller, or gateway and stack. The ADI Chronous product family provides security at every node in the system while minimizing trade-offs in power, performance, and latency.

Deployment Planning

While Industrial Ethernet has made great strides in recent years, fieldbuses and other legacy network technologies are still being used. We all agree that converged networks based on Industrial Ethernet offer many benefits. These include: simplified network architecture, reduced costs by removing gateways, elimination of hardwired connections, improved system optimization, and increased uptime. The ratification of new standards will accelerate this long-awaited transition. The need for higher-performance connectivity networks and a greater degree of integration between OT and IT systems are driving this process. TSN is the foundation for accelerating the implementation of converged networks, and combined with 10BASE-T1L, it enables seamless end-to-cloud connectivity. This migration is a one-time effort, but the potential benefits are so compelling that its adoption may outpace standard industry specifications.

At the heart of the Industry 4.0 vision is the automation of processes using connected devices that have the ability to collect, send, and receive information. ADI Chronous brings data and insights that were previously unavailable through many end-node devices, opening up new areas of data analysis and operational insights. Industrial Ethernet connectivity opens up this new application space by seamlessly transferring existing and future data streams from the automation network to the cloud.

Today, there are still islands of information and insight data that we cannot access, but as industrial Ethernet deployment becomes more popular, the challenges facing Industry 4.0 will shift to security and how to use this data to fully enhance business value. It will be a wise choice to work with a trusted industrial market product partner with decades of experience. Analog Devices has deep domain expertise, technical experience, and a wide range of solutions to help you accelerate your transition to the smart factory of the future.