By Patrick McLaughlin
In the automotive industry, multiple generations of technological advancement have incorporated the use of single-pair copper cabling systems, which support Ethernet transmission. For years, automobile manufacturers have implemented Single Pair Ethernet as a technology that enables communication among an auto’s electronic systems. Today, single-pair communication and single-pair cabling systems are expanding their reach into other areas, specifically including manufacturing and industrial facilities.
In 2019 the Institute of Electrical and Electronics Engineers (IEEE) published the 802.3cg specifications, which define the 10Base-T1L and 10Base-T1S physical layers. 10Base-T1S is intended for short-distance point-to-point communications up to at least 25 meters. 10Base-T1L is used for point-to-point communications over longer distances, up to 1000 meters. The “10” at the beginning of each of these nomenclatures indicates the transmission speed is 10 Mbits/sec.
The case for SPE
In a technical brief describing these technologies, the Ethernet Alliance explains, “Compared to using traditional field buses, using an Ethernet architecture simplifies system implementation since a single software framework can be used from the lowest to the highest speed ranges.
“At the edge, up to 10 Mbits/sec is a major advance for most applications that were previously limited to a data rate of less than 30 kbits/sec,” the alliance continues. “A higher-bandwidth communication link is required to deliver richer datasets from field devices to plant-level infrastructure or up to the cloud for processing. With Ethernet connectivity, it is possible to configure sensors with a laptop or mobile phone, regardless of whether the sensor is on the desk or is deployed in a manufacturing plant.”
Panduit recently published a document titled “The Promise of Single Pair Ethernet,” in which it states, “Industrial operations are being both pushed and pulled to transform their network infrastructure. Industries are at a crossroad with legacy systems nearing end-of-life while at the same time the workforce versed in supporting these systems is also reaching an end to their tour of duty. Forward-thinking organizations are putting in places processes to document and retain this knowledge. But for many, it is unlikely that the collective knowledge of this experienced workforce will be effectively transferred to the new and inexperienced one coming in … Single Pair Ethernet provides a standard Ethernet physical layer that the incoming workforce is already familiar with and presents a clear and cost-effective migration path.
“The automotive industry’s success with Single Pair Ethernet serves to strengthen its foundation for use in manufacturing and process industries,” Panduit adds. “Similarly, these industries are embracing the technology to achieve a single converged network—enterprise to device—and displace the prevalent legacy systems.”
“10Base-T1L supports 10-Mbit/sec transmission over balanced single-pair cabling for connecting a wide range of sensors, actuators, relays, contactors and other low-speed devices used for building automation applications,” explains Siemon in a technical brief covering 10Base-T1L. “Adoption of 10Base-T1L is a milestone step in enabling interoperability and networking of smart industrial IoT devices. The standard supports optional direct current power delivery using IEEE 802.3 power over data lines.”
Standards and products
Within the Telecommunications Industry Association (TR) TR-42 Telecommunications Cabling Systems Committee, several standards are under development related to single-pair cabling. One such standard is ANSI/TIA-568.5 Balanced Single Twisted-Pair Telecommunications Cabling and Components Standard. That standard, which is currently under development and in a balloting process, will include two categories of single-pair cabling—one with a channel reach of 1000 meters and the other with a channel reach of 400 meters. Both categories operate at a frequency range between 0.1 and 20 MHz.
As the TIA’s standards-development groups work toward finalizing the specifications in 568.5, single-pair cabling products and systems are available to the market. Panduit, Siemon, and Reichle & De-Massari (R&M) are among the companies offering these systems.
Siemon is focusing its TERA system, a fully shielded cabling system that has been available on the market for years, on the 400-meter category of 10Base-TL.
Panduit offers single-pair cable and single-pair connectors. “This communications system includes copper cabling and connectivity for a variety of applications and environments, and enables edge devices to be efficiently added to the Ethernet network using only 1-pair cabling rather than 2- and 4-pair cabling,” Panduit says. “This system allows for Power over Data Line power delivery and up to 10-Mbit/sec bandwidth over channels up to 1 km in length, and supports standards in development for 100-Mbit/sec and 1-Gbit/sec bandwidths at shorter channel lengths.”
R&M introduced its single-pair cabling system in June. At the time of the introduction, the company’s market manager for LAN cabling Matthias Gerber said, “Initially, the largest area of application is ceiling cabling, in other words, the digital ceiling. Starting from floor distributors or service nodes in the ceilings, Single Pair Ethernet cabling can spread a long way. The Single Pair Ethernet system from R&M offers a transmission range of 600 meters.”
The system includes two connector styles; LC-Cu complies with IEC 63171-1 for structured cabling and building automation, while MSP complies with IEC 63171-2 for industrial environments.
R&M offering different interface types for different application environments is indicative of the reality that Single Pair Ethernet and its associated cabling will be deployed in smart buildings as well as industrial environments. As user demands evolve, the cabling technology may have to adapt to meet those dynamic demands.
We at Cabling Installation & Maintenance recently conducted an interview with several members of the TIA’s Single Pair Ethernet Consortium. In our next issue, we will provide an in-depth look at Single Pair Ethernet from the consortium’s viewpoint, including the technology’s ability to serve the industrial and smart-building markets.
Patrick McLaughlin is our chief editor.