The macrotrend of urbanization and the resultant impact on climate change is shifting the outlook for building automation and control. Currently buildings account for 40% of all CO2 emissions, with 28% attributed to building operation. As the overall building floor space is predicted to double in the next 40 years, this situation will not improve without focused strategies for building digitization. These efforts are needed to help meet new regulations/certification and drive energy efficiencies to improve sustainability. In parallel, building digitization also enables healthier buildings, improving productivity, and reducing health issues for occupants.
New factories, cars and homes are being networked and automated with internet-connected technologies – Ethernet, wireless internet, and even the latest cellular technology (5G). However, the benefits of automation could also be applied to existing commercial buildings. Unlike homes and vehicles, building automation systems are often built to last decades, with the buildings themselves being purpose-built to stand for 50 to 150 years.
Most existing buildings have very limited control technologies and no real time access to building parameter data or usage statistics. Most of today’s building connectivity is based on legacy analog or short reach digital communication schemes. Naturally, this creates challenges for building management and information technology (IT) professionals tasked with reliably monitoring, providing security, gathering data, and controlling building systems. It restricts access to edge data, which can provide insights into building utilization and enable real time optimization of building parameters to maximize efficiency and occupancy comfort.
There is a unifying solution, however, where a diverse range of sensors, actuators, and building controllers based on 21st century long reach industrial Ethernet technology can be deployed to enable real-time access and control of building assets. This requires deploying a building connectivity network based on single pair Ethernet, 10BASE-T1L. This is a two-wire communication that brings both power and data over long cable runs of up to 1km. This enables Ethernet to edge sensors and controllers, often while using existing cabling infrastructure. This new standard, 10BASE-T1L, brings many advantages to building automation applications that ease the path to upgrading existing structures using low cost and reliable communication and power, along with efficient network configuration options.
This article will discuss the trends in building automation that justify a smarter and more seamless Ethernet-based solution for existing and new buildings. Moreover, it will dive into the advantages of using 10BASE-T1L and how this new standard of communication can be used to fuse the currently chaotic building automation infrastructure into a network as easily managed and accessible as internet networking.
The main challenges facing building automation communication today are:
There are multitudes of buildings standing and in functional use around the world that were built in the times of telegraph machines. There has also been a boom of building construction for nearly a century as the world’s population becomes increasingly urbanized and real estate premiums skyrocket. These circumstances have resulted in legacy buildings in every major city that have a diverse mix of building automation and security systems. With the new trends of greater energy efficiency, lower carbon footprint, improved security, and the business opportunities now available with building and occupant data services, there is now a push to harmonize the divergent building networking systems to enable access to remote monitoring/control and cloud services.
This means removing the need for translation systems and gateways to bridge between the multiple different connectivity networks and protocols. With a connectivity network based solely on Ethernet, data packets can be communicated more efficiently to the cloud from the edge. Removing the translation layers enables seamless, real-time connectivity and for the first time provides the opportunity to deploy a host of new edge sensors to actively manage the building parameters. It also enables power savings at both the electronic level and the macro building level.
The communication standards used in legacy buildings are often built with different network technologies, throughputs, and effective ranges, creating a complex building automation infrastructure that is both hard to maintain and difficult to operate reliably. These factors explain why gateways and translational communication systems have been as prevalent as they are.
Powering these diverse edge electronics is often a burden and requires other dedicated electronics just to power even small sensors. More sophisticated power requirements for edge computing nodes or actuators that use higher power and may require higher-fidelity power supplies necessitate the need for dedicated power sources. The ability to deliver both the data and the power on a single cable saves on cabling runs, cost, and maintenance overheads.
A solution is needed to bring these commercial buildings to the modern age of data, where building management can make use of cloud services, machine learning/artificial intelligence features, and benefit from enhanced reliability and security. Ideally, this solution would be able to operate with adequate bandwidth, long range, and convenient network topology options; include power over the cabling; and use minimal wires. Moreover, the ideal standard would also be common standards-driven and seamlessly integrate with Ethernet IT networking infrastructure. Fortunately, such a standard now exists with 10BASE-T1L, IEEE802.3cg.
Within a Building 10BASE-T1L connectivity enables the following benefits:
Ability to use existing twisted-pair infrastructure for lower-cost retrofits
10BASE-T1L provides for real-time reconfigurability of edge nodes, first step diagnostics of fault remotely without the need to deploy service personnel, and troubleshooting ease, as well as a seamless transition to IT Ethernet-based systems at higher layers in the building network. One big advantage of Ethernet is that it is standards based and possesses intrinsic interoperability. Also, for Ethernet, no special training is needed.
10BASE-T1L, as with any 10BASE-T standard, can support higher level protocol layers like DeviceNet, BACNET IP, KNX IP, MODBUS/TCP and IoT protocols such as MQTT), which enables connection and software control, of a diverse range of edge nodes to cloud services.
To develop a 10BASE-T1L device, you simply require a 10BASE-T1L PHY like the ADIN1100 from Analog Devices, a host processor with integrated medium access control (MAC), and sensor or actuator and measurement electronics. Where a low power processor is used and no MAC interface is supported, the ADIN1110 MAC PHY makes the ideal solution enabling direct interfacing over SPI and reduces the burden on the edge microcontroller in terms of managing broadcast and multicast traffic. The 10BASE-T1L end nodes can then connect to a building or room controller that has 10BASE-T1L enabled ports.
If the room controller only supports standard Ethernet, then a media converter will be required. The media converter only translates the physical encoding and does not modify the content of the Ethernet packets, which makes the media converter transparent to the communication protocol. The network in the building can also be expanded to include 10BASE-T1L field switches that support the connection of multiple local edge nodes and traffic aggregation with uplinks to centralized room or building controllers at the highest data rates possible. The ADIN2111 two port low complexity ethernet switch with built-in 10BASE-T1L PHYs adds Ethernet connectivity to every node in a building, harmonizing the building network with Ethernet to simplify network management. The ADIN2111 is ideal for applications where sensors are connected in line or ring topologies.
With 10BASE-T1L, you can install, provision, and upgrade field devices (end nodes) remotely from a desk via a connected laptop or mobile device. Commissioning time with Ethernet is also drastically reduced due to the higher bandwidth connection, which means instructions are implemented and responses received close to real-time. Hence, building operators can now include new edge nodes into their umbrella of security and maintenance services in a day, as opposed to a week-long process.
Furthermore, as Ethernet technology is essentially ubiquitous, it is not at all challenging to find trained technicians or college graduates educated in Ethernet, where the knowledge and expertise base for many legacy communication standards is shrinking.
Many legacy buildings have a variety of communication protocols and edge sensors/actuators that use at least two-wire, twisted-pair (balanced-line) communications, as well as diverse powering solutions. The power solutions for these sensors may be wired to a building AC unit, rely on special transformers to lower the AC voltage, or voltage conversion from AC to DC. These electronics typically experience wear and tear and could impact the reliability and functionality of the edge sensor, computing, actuator, or security system if not maintained.
Having power and data on the same, venerable, and single twisted-pair communication infrastructure that may already be installed in locations ideal for placing edge electronics can greatly simplify a building automation system while enhancing reliability and reducing maintenance / troubleshooting burdens. This is why 10BASE-T1L supports up to 10 Mbps of full-duplex communication in a DC balanced/point-to-point configuration up to 1 km while delivering up to 52 W of power (cable-dependent) over a single twisted-pair cable. Leading PHYs like the ADIN1100 from Analog Devices require just 39 mW of power, enabling 10BASE-T1L hardware to utilize magnitudes-less power than standard Ethernet Technology.
10BASE-T1L is capable of point-to-point, daisy chain, or ring network topologies, which may further ease the path of upgrading existing building communication infrastructure, as less new cabling is typically needed with a ring topology than with star or point-to-point topologies. Though RS485-based communication systems may be able to achieve up to 100 Mbps with extended capability transceivers, this data rate isn’t achievable over long cable runs. Moreover, RS485 doesn’t support power over the cabling without special electronics, and RS485 systems still require gateways and network translation equipment to work with Ethernet-based networking infrastructure.
Aside from being lower-cost, lighter, and using standards-based cabling and connectors (interchangeable plug-in M8 and M12 connector interfaces that meet M212C2E2/M313C3E3 standards), 10BASE-T1L is also designed from the ground up to be reliable in harsh environments. 10BASE-T1L hardware meets the standards for electromagnetic compatibility for susceptibility and immunity. This may be vital for certain fire and safety or security-based applications, in a world growing rife with electromagnetic interference. Another consideration is safeguarding sensitive edge node data from malicious attacks. With DeepCover® secure authenticators, a cryptographic solution to eliminate these issues can easily be implemented for any system.
The advantage of data line and long-range capability of 10BASE-T1L enables a plethora of new use cases by bringing Ethernet to the edge in buildings. It offers the opportunity to directly develop IP-addressable nodes that can be configured, reconfigured, interrogated, and optimized in real time to maximize building asset usage and occupancy comfort. This brings connectivity to even the most remote end nodes in a building automation network and connects them to the centrally managed cloud enabled systems.
Analog Devices has been leading the charge with 10BASE-T1L, using the organization’s extensive experience as a major supplier of industrial Ethernet with a proven track record in delivering products that exceed standards. It is important for product designers to be mindful of certifications when selecting components for any industrial application, and ADI’s rigorous chip-level testing, unparalleled applications support, as well as recent investments in the area of cyber security and long track record of 50+ years of providing industrial components helps alleviate those concerns.
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