Industrial Automation

SPE’s Role Is Expanding Across Industrial Automation Applications

Dr. Michael Hilgner, Cornelia Eitel, Lukas Bechtel
To decide whether Single Pair Ethernet is the best approach for your application, compare it to other technologies and see which aligns with your pain points.

Single Pair Ethernet (SPE)

As the world continues to run on Ethernet, the uses for Single Pair Ethernet (SPE) continue to grow.


While the technology got its start in the automobile industry, it’s now extending Ethernet communications to field-level devices on the plant floor in process and discrete manufacturing industries. (Learn more about SPE and its move into industrial automation.)


SPE has other application possibilities as well, including:

  • Building automation
  • Freight and passenger trains
  • Warehouses


Weighing the Advantages of SPE

How can you determine whether SPE is the right approach for your application? It’s important to compare the advantages of SPE to the advantages offered by other currently available technologies to see which best aligns with your requirements and pain points.

For example, here are some of the advantages offered by SPE. Which are most critical for your application?


1. Seamless communication

From the sensor to the cloud, SPE enables seamless machine-to-machine and machine-to-human communication. A transparent Ethernet-based network enables IP-based communication between end nodes. Heterogeneous networks require gateways to link network segments that limit end node visibility and accessibility.


2. High bandwidth

Using just one pair of wires for transmission, data throughput for SPE ranges from 10 Mb/s to 1 Gb/s across various distances (the longer the distance, the lower the data throughput).


3. Long transmission distances

SPE can enable higher data speeds to be maintained across longer distances than other technology. Distances related to bandwidth are sometimes referred to as “bandwidth range.”


4. Remote power capabilities

SPE makes it possible to transmit power via the data cores or additional cores of a hybrid cable, enabling remote power (the power supply is located separately from the device).


5. Installation flexibility

Compared to traditional four-pair cables, and depending on the cross-sections of the conductors, an SPE cable has a smaller diameter. It’s also lighter than a four-pair cable. This makes the cables faster and easier to install in tight spaces, such as in a control cabinet.


It’s important to note that some of the advantages listed above can be achieved by non-SPE systems: For example, Nos. 1, 2 and 3 can be achieved by Ethernet via fiber, while Nos. 1, 2 and 4 can be achieved by Ethernet via copper.


The advantages of SPE become apparent only when another highly relevant feature is added. Nos. 1 through 4 above, for instance, represent the advantages of Ethernet Advanced Physical Layer (Ethernet-APL), which is designed for process environments.


In areas with limited space, the combination of Nos. 1, 2 and 5 is relevant. As a result, either the 1,000 Mb/s 40-meter segment, the 10 Mb/s 1,000-meter segment or the 10 Mb/s segment could be suitable.


What TSN Brings to SPE

SPE enables strong growth in Ethernet-capable devices and open network architectures.


In particular, the replacement of specialized gateways and use of switches means that different types of traffic can be mixed with different Quality of Service (QoS) requirements.


For example, SPE enables surveillance cameras to use the same infrastructure as sensors and actuators. However, it’s difficult to meet desired QoS requirements, especially with low bandwidth and mixed traffic classes. Previous Industrial Ethernet protocols are also affected by this, which is why time-sensitive networking (TSN) development began with IEEE 802.1.


TSN is a series of extensions to Ethernet standards that aim to enable deterministic communication over Ethernet networks. TSN provides mechanisms to ensure the transmission of data with guaranteed bandwidth and latency. As a result, TSN is ideal for real-time industrial applications.


Like multi-pair Ethernet, SPE also benefits from these TSN enhancements:


  • Improved determinism. TSN introduces mechanisms that make the transmission of time-critical packets more deterministic than with previously available prioritization schemes. Uniform time synchronization also brings advantages for control processes and network-wide analysis of sensor data and logs.

  • Robustness and reliability. New and standardized redundancy and filter mechanisms promote robustness for critical network segments and specific applications.

  • Transparency and scalability. Ethernet networks allow nearly all devices to be addressed directly. At the same time, creating individual TSN subdivision configuration domains offers the advantage of clear assignment and application-specific configuration to ensure scalability.

Using TSN for Specific Applications

To reduce the complexity of new standards, various industry-specific TSN profiles are being developed. These profiles act as configuration standards that indicate how to use TSN in specific applications.


For example, the IEC/IEEE 60802 TSN Industrial Automation Profile is specifically designed for automation in discrete manufacturing and forms a solid basis for implementation in industrial environments.


The IEEE 802.1DG Automotive Profile and IEEE 802.1DP Aerospace Profile extend the capabilities of TSN to the requirements and challenges faced in automotive and aviation environments.


In addition to reducing complexity, specific properties for individual sectors are also being recognized in TSN profiles.


The current version of the IEC/IEEE 60802 TSN Profile defines uniform network management using NETCONF network management protocol and uniform topology detection using LLDP.


How Manufacturers Are Responding to SPE

As industry-specific SPE variants are standardized through IEEE 802.3 and customer requirements arise from various industries, manufacturers must be ready to respond by:


  • Identifying cross-industry commonalities

  • Prioritizing modular device design with the aim of maximizing the reusability of components for different application areas

  • Aligning with standards so that devices also meet the requirements of other industries


For example, Belden recently launched its Lumberg Automation BEETLE SPE Light Managed Switch to support the transition to future-ready networks built with SPE technology. It aligns with key industry standards, 10BASE-T1L, PoDL and more.


With BEETLE, industrial organizations can scale operations while achieving greater range and long-term cost savings.


Belden continues to help bring Single Pair Ethernet to industrial automation applications so plants can reap the benefits. As SPE continues to gain momentum, we’ll keep you updated.


Learn more about Single Pair Ethernet.


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