SPE Cables - Single-Pair Ethernet
The original concept of Ethernet and its evolution

The name Ethernet became known to the world in the year 1973, when Bob Metcalfe first described the network system that he had conceived, thus making connections of computers to printers possible. Since then, Ethernet has deepened its roots to become the de facto protocol that controls the way data transmits in local area networks (LANs) and wide area networks (WANs).

The original Ethernet was widely used in commercial environments. Industrial Ethernet technology, on the other hand, is mostly used in harsh environments – factories, solar farms, mines and even ocean liners – which constantly place tremendous stress on Ethernet cables and the related components. Dust, moisture, climatic changes and electromagnetic interferences are some of the common challenges.

What is Single Pair Ethernet and how is it different from the usual Ethernet?

Where the conventional Ethernet cables from the LAN sector or Industrial Ethernet cables use two or four pairs of wires depending on the transmission rate, Single Pair Ethernet cables, or SPE in short, are copper cables that contain only one twisted pair (single pair) used for data transmission, such as in industrial applications.

“The Single Pair Ethernet Technology is therefore the leaner, lighter and material-saving Ethernet development for many current and future applications.”
What was SPE developed for…?

Industry 4.0 and the Industrial Internet of Things (IIoT) require uniform network infrastructure across all levels and systems, as well as data transmission in real time. The automotive industry is the first to prove that the SPE theory works – where Ethernet technology had been strategically positioned to become the next network backbone of automobiles, the classic Ethernet, which already connects all upper layers in the automation pyramid, is often unsuitable for connecting the lowest field level because the cables are oversized, and connection is complex.

Here comes SPE cables as the better alternative –

By replacing 4 pair cables in conventional Ethernet with one pair, SPE cables brought about a significant advantage in connecting security systems, diagnostics, vehicle sensors and autonomous vehicle technology.

For automobiles, this reduction in internal cabling weight not only reduces the overall costs of raw material, but also increases fuel efficiency. Conventional fieldbuses, too, have proven their advantages over Ethernet, by controlling the exchange of information between sensors and actuators with the control level (PLC). The next aim is therefore to replace these BUS systems with SPE systems and cables as soon as possible, with these advantages:

Potential replacement of fieldbuses with future-proof Single Pair Ethernet systems
Standardisation of technology in IP-based networks, from sensor to ERP or the cloud, in favour of smart factories
Miniaturisation of the cable leads to material and cost savings on top of a lightweight and space-saving design – especially useful when it comes to networking sensors and actuators
Single-pair cable design enables faster and easier on-site installation while reducing risk of errors during assembly
Existing 2-wire Ethernet infrastructure may be re-used without a massive re-design
Cost-efficient due to the elimination of additional gateways that have previously been used to connect fieldbuses to higher-level standard Ethernet
SPE uses PoDL (Power over Data Line) to supply terminal devices with up to 50W via the data line - comparable to PoE which has already proven itself in today's Ethernet
Open cabling standards with compatible cabling components are suitable for universal use in the entire automation industry

To ensure that IIoT technology is adapted by factories quickly and seamlessly, uniform communication protocols had to be created. The completed standards, according to IEEE 802.3, define the technical framework conditions for Single Pair Ethernet transmissions in industrial applications, with the industrial connector view “T1 Industrial Style” being standardised by IEC 63171-6.

The IEEE 802.3 working group has defined standards for different SPE use cases:

SPE NORM Bitrate Cable length, point to point
Shielded Unshielded
IEEE 802.3 ch 2.5/5/10 Gbit/s 15 m -
IEEE 802.3 bp 1 Gbit/s 40 m 15 m
IEEE 802.3 bw 100 Mbit/s 40 m 15 m
IEEE 802.3 cg 10 Mbit/s 1000 m and more -
A robust pairing of SPE and LAPP
– Meet the LAPP ETHERLINE® T1 product family

LAPP has contributed to the SPE cable development with the introduction of the ETHERLINE® T1 product family, which consists of various Single Pair Ethernet cables for use in industrial machinery and plants:

FD P 1x2xAWG26/7
is a shielded AWG26 cable for Gigabit and used in cable chains
(available soon)
# 2170921
PUR outer sheath
Cable chain
Up to 1 Gbit/s
Max. 40 m
UL AWM 80°C, 300 V
Y FLEX 1x2xAWG22/7
is an AWG22 cable for occasional movement and is suitable for
100 Mbit and Gigabit
# 2170922
PVC outer sheath
Occasional flexing
100 Mbit/s - 1 Gbit/s
Max. 100 m
P FLEX 1x2xAWG18/7
is an AWG18 cable for 10 Mbit/s and distances of up to 1000 m
(available soon)
# 2170924
PVC outer sheath
Permanently installed
10 Mbit/s
Max. 1000 m
UL (in preparation)
Driving the SPE momentum with a strong partnership

“Since incompatible components hamper market penetration, it is important for us to develop a standard to help the products break through,”

– Ralf Moebus, Head of Product Management for Industrial Communication at LAPP

In order to accelerate this move to the mainstream, LAPP has decided to be a member of the SPE Industrial Partner Network, a consortium of well-known companies that want to help SPE technology achieve a breakthrough to the mainstream.

Aiming to create an integrated SPE infrastructure, this meaningful partnership will create standardised interfaces and system components – and the engine of innovation has been kickstarted, with the establishing of standards and close cooperation with international committees.