Single Pair Ethernet: Industrial Automation Stakeholders Weigh In
As Single Pair Ethernet (SPE) extends the use of Ethernet technology beyond automotive applications to sensors and actuators in industrial automation, SPE becomes more visible to and accessible by various user groups.
In a recent blog, we covered the five technical SPE features that leaders in industrial environments can use to determine the relevance of the technology for their specific applications. These features include:
- Seamless communication
- High bandwidth
- Long transmission distances
- Remote power capabilities
- Installation flexibility
But deciding whether to deploy SPE is rarely this simple. The decision to use Single Pair Ethernet is often made by a group of stakeholders with differing priorities and opinions on which SPE features and benefits are most critical or relevant.
Below, we introduce the stakeholders who are typically involved in the SPE decision-making process, as well as their specific interests and opportunities when it comes to SPE technology.
Construction and Installation Professionals
Communication technology choices have a major influence on the decision to move forward with SPE. Weight, cable routing, installation of data and power cabling, maintenance, and fire protection must be taken into account.
In some applications, SPE offers advantages over today’s physical transmission standards:
- SPE cables can reduce weight compared to other types of copper-based cabling.
- With a small outer diameter and bend radius, SPE can simplify cable routing.
- In harsh industrial environments, copper-based transmission, such as SPE, offers durability advantages over fiber-based systems.
- Thanks to SPE’s remote power capabilities, a single data cable can be used to transmit data and provide power. This can be achieved similar to Power over Ethernet (PoE) via the data pair or by using hybrid cables.
Construction of a train is an application where SPE may be beneficial: This is a weight- and space-sensitive environment that exposes cables to harsh conditions. Here, the use of SPE cables for networking control, monitoring systems, and passenger information systems within the train offers significant advantages.
Smaller, lighter-weight cables streamline cable routing, take up less space on the train, and increase flexibility for trouble-free installation. This significantly reduces the overall weight of the train, which improves energy efficiency and performance (a lower mass makes it easier to accelerate and decelerate).
The cables do not break easily in tight installations or under vibration. At the same time, SPE’s remote power capabilities use data-transmission cables to enable an efficient power supply for sensors, cameras, and displays.
The result: better operational efficiency, safety, and passenger experiences.
Network Administrators
Once a system is installed, a network administrator must distribute the addresses and authorizations of the communication participants in the network.
SPE’s features of seamless communication and remote power play a central role in simplifying network installation and maintenance while supporting common security mechanisms. Seamless communication simplifies integration and management of network components by providing a unified, IP-based communication platform to the sensor/actuator level.
This reduces the complexity of network commissioning and supports the efficient application of security mechanisms, such as IEEE 802.1X, and enables end-to-end authentication and encryption across all network levels. SPE’s remote power supply also helps streamline the installation and maintenance of devices by eliminating the need for separate power cables, which is particularly useful when setting up network components in hard-to-reach or remote areas.
An example of this can be found in the creation of a secure network in a large warehouse, where SPE is used to integrate a variety of surveillance cameras and access control systems.
By using SPE, these devices can be easily connected to data and power over a single cable, significantly reducing installation costs and complexity while facilitating compliance with security standards through IEEE 802.1X to ensure secure and reliable network operation. However, for network-enabled devices, this calls for extra effort in implementing the required functions compared to fieldbuses and potentially requires more hardware resources, such as computing power or memory.
Application Programmers
The seamless communication and bandwidth features of SPE are particularly important for application engineers who are involved in programming systems and carrying out factory acceptance tests (FATs). SPE supports efficient, end-to-end IP-based communication, which enables direct and uncomplicated networking of sensors, actuators, and control units.
This simplifies the programming and integration of system components, as there are fewer restrictions in terms of compatibility and connectivity. For example, an application engineer can switch flexibly between sensor manufacturers without having the connection as a central selection criterion. At the same time, the switch from fieldbus to Ethernet technology provides end devices with more bandwidth so that additional diagnostic data can be retrieved.
In contrast to four- and eight-wire Ethernet connections, SPE enables the use of compact connectors and lighter cables. Compared to fieldbuses, however, SPE requires the implementation of a complete IEEE network stack, which creates additional development costs. Standards development organization ODVA has accepted this challenge and has responded with a reduced functional scope of EtherNet/IP for devices with severe hardware limitations (“constrained devices”). This includes CIP Security with pre-shared keys and control data exchange exclusively via UDP.
Application Operators
For application operators tasked with the control, maintenance, and servicing of systems, the remote power and seamless communication features of SPE play a central role.
Remote power makes it possible to supply end devices, such as sensors and actuators, with power via Ethernet cables, which simplifies installation and maintenance, especially in difficult-to-access or large-footprint areas.
This becomes even more important in the context of remote monitoring and control of installations that use SCADA systems, which require reliable and parallel communication for process control and monitoring. The seamless communication offered by SPE is crucial here to ensure uniform IP-based networking to the sensor/actuator level.
This end-to-end connectivity not only facilitates the integration of different system components but also supports the parallel transmission of control commands and real-time data acquisition for SCADA systems.
A concrete example of this is the remote control and monitoring of a distributed power generation system. By using SPE, application operators can monitor the output of solar panels and wind turbines in real-time and simultaneously send control commands to inverters and load management systems, ensuring optimum energy yield.
The combination of remote power supply and seamless communication enables efficient, reliable, and cost-effective operations management, which is essential for modern infrastructure management. Until now, remote monitoring and control has not been implemented directly with sensor data, but the controllers in the processes have provided aggregated data to SCADA systems. This reduces demand for the sensors in fieldbus applications but requires regular adaptation of the control programs to extract current data.
Data Scientists
For data scientists involved in plant-wide data analysis, predictive maintenance, and control optimization, SPE’s bandwidth and seamless communication features are particularly important. The high bandwidth of SPE enables the fast transmission of large amounts of data required for analysis and machine learning. This is crucial for gaining real-time insights and developing accurate predictive models. Seamless communication also facilitates the integration of data from disparate sources via a unified interface, reducing the complexity of data collection and enabling more comprehensive data analysis.
A practical example of this is the optimization of production processes in a manufacturing plant. A data scientist can use SPE to collect data from sensors on machines at high frequency and use this information to develop predictive maintenance algorithms. By analyzing this data, potential failures can be detected, and maintenance work can be proactively planned before unplanned downtime occurs.
The combination of high bandwidth and seamless communication enables efficient data collection and analysis, leading to a significant increase in plant availability and optimization of operational processes. In current fieldbus environments, sensor connections are isolated by controllers that act as gateways. As a result, data scientists cannot retrieve the sensor data in the required resolution. This limitation restricts their role in current fieldbus environments.
Belden’s Focus on SPE
As industry-specific SPE variants continue to be standardized through IEEE 802.3 and stakeholders consider the technology for their industrial automation applications, Belden will help lead the charge in bringing Single Pair Ethernet to industrial automation applications so plants can reap the benefits.
Our Single Pair Ethernet portfolio of cabling and connectivity products is designed to optimize Ethernet connection possibilities in harsh environments, including industrial and transportation operations.
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About the Author
Lukas Bechtel has been with Belden since 2012, rising through the ranks from test automation engineer to technology architect in our CTO office. He’s also a faculty member and researcher at Esslingen University, where he teaches students about IT and network security and industrial networks while studying areas like Industry 4.0, wireless communication and industrial communication and security.