In today's networked world, data transmission via Ethernet plays a crucial role. SPE (Single Pair Ethernet) simplifies data transfer, offering completely new possibilities and challanges for industrial applications. In the following FAQ, 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.
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 interruption down to the field level of the automation pyramid. This simplifies access to sensor data from the field level and the implementation of applications.
The OSI model (Open Systems Interconnection Model) is a reference model for data communication standards to promote interoperability between heterogeneous network topologies. The reference model is divided into 7 different 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: (1) Physical Layer, (2) Data Link Layer, (3) Network Layer, (4) Transport Layer, (5) Session Layer, (6) Presentation Layer, (7) Application Layer
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.
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.
Single Pair Ethernet (SPE) offers several advantages, particularly in the field of industrial automation and device networking. The most important benefits include
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.
Less cable material leads to lower costs for the cables themselves and for installation. Maintenance costs can also be reduced.
SPE supports real-time data transmission, which ensures improved process control and increased safety in industrial applications.
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.
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 IEEE 802.3cg standard of the technological subgroup used.
SPE systems are often designed for harsh industrial environments, making them more resistant to environmental influences and mechanical stress.
SPE can transmit data over longer distances than conventional Ethernet, which can be an advantage in large industrial plants or buildings.
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.
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.
Single Pair Ethernet (SPE) enables various data transmission rates, which can vary depending on the technical requirements and cable length. These include
These transmission rates are designed for applications where reliability is more important than high speed. A distinction is made between two main types:
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.
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.
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 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 |
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.
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.
The Single Pair Ethernet Systems Alliance focuses on the development, standardization and dissemination of SPE. Its main objectives ir />
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.
