Engineering 101

The Crucial Role of Testing in Automotive Ethernet Standards

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Autopilot systems used to be for air, marine or spacecrafts — but today’s car drivers are increasingly relying on technologies to serve as ‘an extra pair of eyes and ears’ and help them stay safe on the road.

Here, Martin Frederiksen, Managing Director at Recab UK, has explained why development tools for automotive Ethernet are ever more crucial to today’s driver safety systems.

The earliest innovations in car safety came from unlikely places. The windscreen wiper was invented by a cattle rancher, Mary Anderson; while Florence Lawrence, a Hollywood starlet, pioneered the turn signal. These technologies have saved countless lives, of course. But it wasn’t until many years later — and the involvement of major car manufacturers, like General Motors (GM) with its introduction of the airbag in 1973 — that stringent testing of these systems became mandatory.

As today’s drivers rely more on advanced driver assistance systems (ADASs) for safety, like lane-centring systems or advanced cruise control, technologies have to meet increasingly stringent testing standards. From the latest entertainment technologies to ADASs like lane-keep assistance or automated emergency braking, there are more requirements for Ethernet based networks in vehicles than ever before.

According to draft European Union (EU) rules, manufacturers of ADASs will be required to show how these systems safely return control back to the driver, monitor the road and how they react in emergency situations. There are also non-binding performance ratings, like Europe’s New Car Assessment Program (or Euro NCAP). A windscreen wiper designed by a cattle rancher simply won’t cut it anymore.

New Communication Architectures

This is where Automotive Ethernet is playing a vital role. Not only in allowing communications between in-car systems within the vehicle itself, but also in testing these systems at the pre-development stage in ways that suit the standards.

Automotive Ethernet is used in communication between different electronic control units (ECUs), the embedded systems in automotive electronics that control one or more of the electrical systems or subsystems. Previously, automotive busses like CAN, LIN, MOST and FlexRAY were established as the most common communication paths. However, these established bus systems cannot support the high-bandwidth sensors that are used for ADASs. Ethernet is advantageous over these existing bus systems. It keeps the simple and cost saving wiring as used in CAN using a twisted pair of cables.

That’s why Ethernet-based communications — which, for decades, have been associated with offices or factories — are playing an increasingly-vital role in vehicle diagnosis.

Stopping Disruptions

Aside from greater bandwidth and simple cabling, Automotive Ethernet is also scalable with the capability to virtually separate different local area networks (VLAN) while also being compatible with Car2X Communication, where data comes from infrastructure or other vehicles, without media disruption.

Testing Automotive Ethernet

At the testing stage for safety equipment, the right development tools are critical for the insights in ECU communication, ensuring that ECUs are communicating with each other properly, and the right signals are being sent. Data is transferred point to point in full duplex mode, which makes it difficult to listen to data packets during development between two ECUs without influencing the communication. This includes NETLion 1000 by Recab UK’s longstanding and trusted supplier, b-plus, of Deggendorf, Germany.

NETLion is a development tool that decouples data from both ways of communication as a test access point (TAP). In an additional operation mode it converts the data of automotive Ethernet to standard Ethernet used in IT communications. This way it supports the developer to analyse communication during test and development. It also supports checks for signal quality and cable tests.

Crucially, the NETLion 1000 is designed to support the 1000BASE-T1 standard for one direct point-to-point conversion between automotive ECUs. The standard defines the transferral of Gigabit (Gbit) Ethernet over a single twisted pair cable for both automotive and industrial applications. It includes cable specifications for 15 metres (type A) or 40 metres (type B) reach. NETLion can convert up to two 100Base-T1 or 1000Base-T1 signals into 100BASE-TX or 1000BASE-T Ethernet; the latter is common in IT applications.

The small NETLion box’s role might seem simple, but handling new Automotive Ethernet architectures is among the biggest challenges for OEMs, especially to migrate and validate functionality to 1000BASE-T enabled ECUs. It’s vital that Ethernet communications within a vehicle are taken care of. The NETLion is designed to facilitate this with an easy use, and the ability to analyse the pre-testing data afterwards with software by analysing 100/1000BASE-T1 physics as 100BASE-TX/1000BASE-T Ethernet.

Automotive Ethernet Expanding to Other Markets

Going forward, automotive Ethernet will benefit other markets such as commercial vehicles, agriculture vehicles like tractors and even drones. Development tools like NETLion 1000 are crucial as technologies like high bandwidth sensors and cameras evolve and become more common. Recab UK can support its customers in these varied applications where such development tools can prove crucial.

For now, the advantages of ADASs are huge — according to the UK’s Department for Transport, failing to look, loss of control and poor manoeuvring contributed towards 63 per cent of fatalities in reported road accidents in 2018. By ensuring the automotive Ethernet systems are fully operational at the initial testing stage, OEMs can guarantee that ADASs give motorists the extra, trusted pair of eyes and ears they need.

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