Digitalization

Single Pair Ethernet – The top technology

In today's networked world, data transmission via Ethernet plays a crucial role. This has been particularly true since the introduction of Single Pair Ethernet, which has opened up completely new possibilities and challenges for industrial applications. In the following article, we answer all the important questions about networking and integrating field devices and sensors based on Single Pair Ethernet and the associated benefits for industrial processes.

Table of contents

What is Single Pair Ethernet?

Single Pair Ethernet, or SPE for short, is Ethernet-based communication that forms the basis for a variety of transmission protocols. The end-to-end concept enables direct data transmission between the sensor and the cloud, resulting in seamless communication without media discontinuity across all levels of the automation pyramid. This simplifies access to sensor data from the field level and the implementation of applications. In some cases, the technology is also incorrectly referred to as "Single per Ethernet".

What does the OSI model mean?

The OSI model (Open Systems Interconnection Model) is a conceptual framework that describes the standardized functions of a communication or computer network. It divides network communication into 7 successive layers, with each layer having specific tasks and functions. It helps to structure and standardize complex network communication. Single Pair Ethernet is located at the lowest level, the so-called physical layer.

OSI-Modell

OSI-Modell: (1) Physical Layer, (2) Data Link Layer, (3) Network Layer, (4) Transport Layer, (5) Session Layer, (6) Presentation Layer, (7) Application Layer

How does SPE differ from traditional Ethernet?

The main difference lies in the number of cable pairs in the data cable used. While traditional Ethernet uses 2 or 4 cable pairs depending on the transmission rate, SPE only requires a single twisted pair of wires in the shielded data cable. In addition, the innovative technology based on the 10BASE-T1L standard enables cable lengths of up to 1,000 meters, whereas previously cable lengths of only 100 meters were common.

What does the abbreviation 10BASE-T1L mean?

The abbreviation 10BASE-T1L is a term made up of several partial aspects that contains the relevant information about the network connection. For example, the number 10 indicates the transmission rate of 10 Mbps. The term "BASE" refers to the type of signal and means that Ethernet signals can be transported via the data cable. "T1" stands for "Twisted Pair" and the abbreviation "L" for Long Distance, which means that data cable lengths of up to 1 km are possible.

What are the advantages of Single Pair Ethernet?

Single Pair Ethernet (SPE) offers several advantages, particularly in the field of industrial automation and device networking. The most important benefits include

Reduction of cable complexity

SPE uses only one-pair copper data cables instead of the usual two- or four-pair data cables. This simplifies the cable architecture/assembly and reduces weight and space requirements. This makes installation and routing in complex machines and systems much easier, even in applications where the data cable is subject to high bending stress.

Cost savings

Less cable material leads to lower costs for the cables themselves and for installation. Maintenance costs can also be reduced.

High data transmission rates in real time

SPE supports real-time data transmission, which ensures improved process control and increased safety in industrial applications.

Power over Data Line (PoDL)

During data transmission, power is also supplied via the same cable pair. This makes it easier to power devices and eliminates the need for separate power cables.

Easier connectivity and integration

SPE facilitates integration into existing Ethernet infrastructures and supports standardized Ethernet protocols, which simplifies connectivity and integration into networks. All that is required is a single pair Ethernet switch with the corresponding supported IEE 802.3 standard of the technological subgroup used.

Improved reliability and robustness

SPE systems are often designed for harsh industrial environments, making them more resistant to environmental influences and mechanical stress.

Long distance transmission

SPE can transmit data over longer distances than conventional Ethernet, which can be an advantage in large industrial plants or buildings.

Future-proof

With the growing number of IoT devices and the need to network them efficiently, SPE offers a future-proof solution that keeps pace with the requirements of modern and future network applications.

What applications is SPE technology suitable for?

Thanks to the barrier-free connection of field devices, Single Pair Ethernet is a door opener for innovations from which many sectors and branches of industry can benefit. In particular, this includes industrial networks, automotive applications, building automation and other applications where a robust, cost-efficient or space-saving cabling solution is required. Single Pair Ethernet is also the technology of choice for use in harsh industrial environments or for climate monitoring in large warehouses and greenhouses. Finally, the immense cable length means that sensors can also be integrated over long distances.

What data transmission rates does SPE support?

Single Pair Ethernet (SPE) enables various data transmission rates, which can vary depending on the technical requirements and cable length. These include

10 Mbps (10BASE-T1 according to IEE 802.3cg standard)

These transmission rates are designed for applications where reliability is more important than high speed. A distinction is made between two main types:

  • T1S (Short Distance): This variant is intended for short distances and supports multi-drop operation, in which up to 8 devices can be connected in an unshielded cable harness up to 25 meters in length.
  • T1L (Long Distance): This variant enables point-to-point Ethernet connections over a length of up to 1000 meters. A shielded two-wire cable is used here, which also supports Power over Data Line (PoDL).

100 Mbps (100BASE-T1 according to IEE 802.3bw standard)

This speed is often used in automotive networks, where it offers a good balance between speed and cost efficiency. With an unshielded cable harness, the maximum length is 15 m.

1 Gbps (1000BASE-T1 according to IEE 802.3bp standard)

This higher transmission rate is ideal for applications that require faster data transmission, such as in certain industrial applications or advanced vehicle systems. A length of 15 m can be realized with an unshielded cable, while a shielded cable offers a range of up to 40 m.

2.5/5/10 Gbps (Multi-Gig according to IEE 802.3ch standard)

The multi-gig data transmission rates can be used to cover applications in the automotive sector that require very high bandwidths, such as driver assistance systems or autopilot systems. A length of 15 m can be realized here with shielded data cables.

Timeline of data transfer rates


Timeline IEEE 802.3 IEEE 802.3 Standard Max. Distance Speed Bandwidth Category according ISO/IEC TR11801-... Pairs
2015 IEEE 802.3bw 100BASE-T1 15 m UTP 100 Mb/s 66 MHz SPE 1
2016 IEEE 802.3bp 1000BASE-T1 40 m
15 m UTP
1000 Mb/s 600 MHz SPE 1
2019 IEEE 802.3cg 10BASE-T1L
10BASE-T1S
1000 m
25 m UTP
10 Mb/s 20 MHz SPE 1
2020 IEEE 802.3ch Multi-Gig (15 m) 2.5/5/10 Gb/s SPE 1

Are there any special requirements for the installation of SPE?

Several factors are crucial to ensure efficient data transmission and end-to-end networking. These include the type and quality of the cables, SPE-capable hardware (SPE switches, routers and end devices) and the right connectors and connections. Careful planning of the network design, consideration of the environmental conditions and professional installation are also required.

Which manufacturers offer Single Pair Ethernet sensors?

Single Pair Ethernet technology is an innovative technology that has so far only been offered by individual sensor and automation technology companies. It is successfully marketed by two different alliances of technology drivers. The best known is the Single Pair Ethernet Systems Alliance, which provides a good overview of potential sensor and technology providers in its member directory.

What are the goals of the Single Pair Ethernet Systems Alliance?

The Single Pair Ethernet Systems Alliance focuses on the development, standardization and dissemination of SPE. Its main objectives ir />

  1. Promoting SPE technology: A primary goal of the Alliance is to increase awareness of the benefits and application possibilities of SPE. This includes highlighting the efficiency, cost benefits and improved performance that SPE offers over traditional Ethernet solutions.
  2. Development and standardization: The Alliance is working on the development and standardization of SPE to ensure broad interoperability and compatibility between different devices and systems. This includes work on technical specifications, performance requirements and standards.
  3. Collaboration between members: The Alliance encourages collaboration between its members, who come from different industries and sectors. This facilitates the exchange of knowledge and experience and supports the development of innovative SPE solutions.
  4. Market development: It supports the development of the SPE market through various initiatives, including marketing activities, trade fairs and conferences to make the technology accessible to a wider audience.

What does the future of Single Pair Ethernet look like?

Single Pair Ethernet is considered a pioneer of process automation and has the potential to fundamentally change the way data is transmitted in industrial and industry-related applications. It is therefore enjoying growing industrial acceptance and will play a key role in IoT applications in the future. These include smart city applications, intelligent buildings, connected vehicles and more. From a technical perspective, there is no way around Single Pair Ethernet.