Accurate Technologies - Blog #AE1000

What Is ASAM MDF4 and Why Is It Used?

Fri, 14 Aug 2026 13:07:33 -0400

Part 1 - ASAM MDF4 Explained

Modern vehicle development generates enormous amounts of measurement data. Whether engineers are calibrating an ECU, validating a control strategy, testing a powertrain, or recording data from a vehicle network, hundreds or even thousands of signals may need to be captured simultaneously.

Storing those measurements is only part of the challenge. The data also needs context: What does each signal represent? What are its units? How should a raw value be converted into a physical value? When was each sample recorded? How are signals with different sampling rates synchronized?

This is where ASAM MDF (Measurement Data Format) comes in.

MDF is a standardized binary file format designed for storing measurement data together with the information required to interpret it. MDF4, the fourth major generation of the standard, was designed to support the increasingly large and complex datasets produced by modern automotive development and testing.

What Is ASAM MDF?

MDF stands for Measurement Data Format. The standard is maintained by ASAM (Association for Standardization of Automation and Measuring Systems) and is widely used for measurement and test data, particularly in automotive development.

An MDF file is more than a collection of recorded values. It can contain both the measurement samples and metadata describing those measurements.

Depending on the recording, this can include information such as:

Signal and channel names
Raw measurement values
Physical units
Conversion information
Time information
Sampling information
Descriptions and other channel metadata
Events and attachments
Vehicle network data

Keeping this information together makes MDF useful for exchanging measurement data between acquisition, calibration, validation, and analysis tools.

Files based on MDF 4.x commonly use the .mf4 file extension.

Why Does a Standard Measurement Format Matter?

Consider a relatively simple test.

An engineer records engine speed, temperatures, pressures, pedal position, ECU parameters, and CAN traffic during a vehicle test. Some measurements may be sampled every millisecond, while others are recorded much less frequently.

A simple tabular format can represent some of this information, but it quickly becomes inefficient as recordings become larger and more complex.

There are several questions the file format needs to answer.

How do signals with different sampling rates coexist? How are timestamps represented? How is a raw ECU value converted into an engineering unit? How can very large recordings be stored efficiently? How can another application interpret the recording without knowing the details of the original acquisition system?

MDF was created to provide a standardized way of representing this type of measurement data.

That standardization is important because the application recording the data does not necessarily have to be the application analyzing it.

Why MDF4?

Earlier versions of MDF had already established the format within automotive measurement and calibration workflows. However, measurement systems continued to evolve.

ECUs became more complex. The number of measurable parameters increased. Vehicle networks generated more data. Sampling rates increased. Test durations became longer.

As a result, measurement files could become extremely large.

MDF4 introduced an architecture better suited to these requirements while retaining the core idea behind MDF: store measurement data together with enough information to correctly interpret it.

One of the key characteristics of MDF4 is its block-oriented structure.

Instead of treating a measurement file as one large table, MDF4 organizes information into interconnected blocks. Different blocks can describe the file, data groups, channel groups, individual channels, conversions, actual measurement data, events, attachments, and other information.

This architecture gives MDF4 considerable flexibility.

For example, a recording can contain multiple groups of measurements with different structures and timing characteristics rather than forcing every measurement into one universal sample rate.

We'll look much more closely at this block structure in the next article in this series.

MDF4 Is More Than Signal Values

When engineers first encounter an MF4 file, it is easy to think of it as simply a container for signal-versus-time data.

There is considerably more happening underneath.

Imagine that a measurement system records an ECU parameter as the integer value: 2150

That number alone may not tell an engineer very much.

The MDF4 file can also describe the channel, its unit, and the conversion needed to turn the stored value into a meaningful physical value.

The result might be something such as: 21.5 °C

This distinction between stored/raw values and physical engineering values is fundamental to working with measurement data.

MDF4 can preserve the information needed to make that interpretation part of the dataset rather than relying entirely on external knowledge.

Handling Different Sampling Rates

Another important measurement challenge is time.

Not every signal in a vehicle or test system is acquired at the same rate.

For example:

One group of signals might be sampled every 1 ms.
Another might be sampled every 10 ms.
A slower temperature measurement might update every 100 ms.
Network messages may arrive according to their own timing.

Trying to force all of this information into one large table can result in duplicated timestamps, empty values, interpolation, or unnecessarily large files.

MDF4 provides structures that allow related channels and their timing information to be organized efficiently.

This is one reason understanding concepts such as data groups, channel groups, channels, and master channels becomes important when working with MDF4.

Designed for Large Measurement Files

Measurement files can grow quickly.

Recording 1,000 channels at high sampling rates for an extended test can generate millions (or billions) of individual samples.

MDF4 includes mechanisms intended to make storing and accessing these datasets practical. Among them are support for compressed data blocks and structures that allow measurement data to be organized according to how it was acquired.

These features also introduce an important distinction between MDF4 and simpler formats such as CSV.

CSV is extremely useful when data needs to be human-readable or easily exchanged with general-purpose applications. But representing a large, complex measurement recording as rows and columns can significantly increase file size and lose some of the richer structure associated with the original measurement.

MDF4 was designed specifically around measurement data.

Where Is MDF4 Used?

MDF4 is particularly common in automotive engineering, although its underlying concepts apply to other measurement environments as well.

Typical applications include:

ECU calibration
Vehicle testing
Powertrain development
Electrified powertrain and battery testing
Controls development
Validation and verification
Data acquisition
Vehicle network recording
Test bench measurements
Measurement data exchange and post-processing

A common workflow might look like:

Measurement → MDF4 recording → Analysis → Engineering decision

The recording application captures the test in MDF4, and engineers can then use an MDF4-compatible analysis application to inspect signals, compare tests, calculate derived quantities, or investigate events.

For example, ATI VISION Data Analyzer (VDA) can work with MDF4 measurement files for post-processing and analysis, including MDF4 files generated by third-party measurement systems. This illustrates one of the practical advantages of using a standardized measurement format: acquisition and analysis do not necessarily need to happen in the same software environment.

MDF4 vs. MDF3

MDF3 files are still encountered in existing measurement environments, so it is useful to understand that MDF4 is not simply MDF3 with a new file extension.

MDF4 introduced substantial changes to the underlying file architecture to better accommodate modern measurement requirements, including increasingly large and diverse datasets.

For users, both formats may ultimately present familiar concepts, channels, timestamps, values, and units.

For software reading the files, however, their internal structures are significantly different.

This becomes especially important when developing data-processing tools or troubleshooting why a particular application handles one MDF generation differently from another.

Why Engineers Should Understand MDF4

Most engineers working with MF4 files will never need to implement an MDF4 parser.

But understanding the basic structure of the format can still make everyday data analysis easier.

It helps explain why two signals may have different time bases, why extracting a channel from a very large recording can involve more work than expected, why raw and physical values can differ, why file compression affects analysis performance, and why converting an MDF4 recording to a simpler format may discard useful information.

Understanding what is inside the file makes it easier to understand what your analysis software is doing with it.

What's Next: Inside an MDF4 File

So far, we've treated MDF4 largely from the outside: what it is, why it exists, and the types of problems it solves.

The next step is to look inside.

In the next article in this series, Inside an MDF4 File: Understanding the MDF4 Data Structure, we'll explore the block-based architecture behind MDF4 and introduce the relationships between file headers, data groups, channel groups, channels, conversions, and the blocks containing the actual measurement data.

Once those relationships are clear, an MF4 file stops looking like a mysterious binary file and starts looking like a structured representation of the measurement system that created it.

Automotive Ethernet Explained Pt. 6

Fri, 12 Jun 2026 12:01:04 -0400

Getting Started with Automotive Ethernet Tooling

Automotive Ethernet introduces new capabilities, but it also introduces new tooling requirements.

CAN tools are still important, especially in mixed-network vehicles, but Ethernet adds packet-based communication, IP diagnostics, service discovery, synchronization, and high-bandwidth data streams. Engineers need tools that can see more than raw traffic. They need tools that understand how Automotive Ethernet behaves inside the vehicle.

Why Tooling Matters

Automotive Ethernet networks are more complex than traditional CAN networks.

Instead of only looking at message IDs and signal values, engineers may need to analyze:

Ethernet frames
IP traffic
SOME/IP services
DoIP diagnostic sessions
AVB or TSN timing behavior
Gateway routing
CAN, CAN FD, and LIN interaction

Without the right tools, it can be difficult to understand where a problem starts and how it affects the rest of the vehicle network.

What Engineers Need on Day One

Getting started with Automotive Ethernet typically requires a few core capabilities.

At minimum, engineers need to be able to:

Connect to Automotive Ethernet networks
Monitor live traffic
Decode common automotive protocols
Log data for later review
Generate or stimulate traffic
Validate diagnostics over Ethernet
View CAN and Ethernet behavior together

The goal is not just to capture packets. The goal is to understand what the vehicle network is doing.

Engineers also benefit from tools that provide a unified view of the vehicle network. As modern architectures combine CAN, CAN FD, LIN, and Automotive Ethernet, switching between multiple disconnected tools can slow troubleshooting and validation efforts. ATI's VISION® platform helps engineers monitor, analyze, and interact with multiple vehicle networks from a single environment.

Monitoring vs Active Testing

There are two common tooling modes: monitoring and active testing.

Monitoring means observing traffic without interfering with the network.

This is useful for:

Debugging communication issues
Reviewing network load
Capturing intermittent faults
Understanding ECU behavior

Active testing involves sending traffic, simulating ECUs, or injecting faults.

This is useful for:

ECU bring-up
Gateway validation
Diagnostics testing
Stress testing
Reproducing edge cases

Both are important. Development teams often rely on active testing early, while validation teams need strong monitoring and repeatable test execution.

For example, engineers may use ATI's VISION® platform to monitor data that an ECU is receiving from other connected nodes. This can be used to identify message decoding issues in the ECU software. During development, these same environments can be paired with simulation and gateway solutions to actively test communication scenarios and validate system behavior.

Scaling from Bench to Vehicle

Automotive Ethernet testing usually starts on the bench.

A bench setup might include:

One or more ECUs
A gateway
CAN or CAN FD networks
An Ethernet connection
Diagnostic or simulation tools

As development progresses, testing moves into the full vehicle. At that point, complexity increases significantly.

Engineers must validate:

Multi-network traffic
Gateway behavior
Latency and jitter
Diagnostic routing
System-wide fault behavior

As testing progresses from bench setups to full vehicle environments, maintaining consistent workflows becomes increasingly important. Tools that support both development and validation activities help reduce rework and improve efficiency. ATI's portfolio, including VISION® and its Vehicle Communication Gateway, can be used throughout the development lifecycle, from early ECU bring-up and diagnostics to vehicle-level network validation.

Avoiding Common Beginner Mistakes

One common mistake is treating Automotive Ethernet like office Ethernet.

Standard IT tools can be helpful, but they are not enough on their own. Automotive networks require visibility into vehicle-specific protocols, timing requirements, and mixed-network behavior.

Another mistake is testing Ethernet in isolation. In most vehicles, Ethernet works alongside CAN, CAN FD, and LIN. A problem may appear on Ethernet but originate from a gateway, diagnostic route, or CAN-side message.

Effective tooling should help engineers see the whole system, not just one network segment.

What to Look for in Automotive Ethernet Tools

When evaluating tools, look for capabilities such as:

Automotive Ethernet interface support
CAN, CAN FD, and LIN support
SOME/IP and DoIP decoding
Logging and replay
Traffic generation
Gateway testing support
Time synchronization analysis
Fault injection
Scalable bench and vehicle workflows
Unified visibility across CAN, CAN FD, LIN, and Automotive Ethernet networks

Modern vehicle architectures require engineers to understand how multiple networks interact. Solutions such as ATI's VISION® platform are designed to provide that visibility, helping teams analyze communication, diagnose issues, and validate system behavior across the entire vehicle network.

The right tool should support both development and validation needs without forcing teams to switch workflows entirely.

Why This Matters

Automotive Ethernet is becoming a foundation for modern vehicle architectures. As networks become faster and more interconnected, engineers need tools that provide visibility across the entire system, not just individual buses. Platforms such as ATI's VISION® help development and validation teams monitor network activity, troubleshoot issues, and better understand interactions between Ethernet, CAN, CAN FD, and LIN networks.

The better the tooling, the easier it is to debug issues early, validate system behavior, and reduce risk before vehicle-level testing.

Looking to Simplify Automotive Ethernet Development and Validation?

Modern vehicles rely on a mix of CAN, CAN FD, LIN, and Automotive Ethernet networks. ATI's VISION® platform and Vehicle Communication Gateway help engineers monitor, analyze, diagnose, and validate communication across these mixed-network environments, supporting both development and validation workflows from the bench to the vehicle.

Up Next

In the next post, we will look at common Automotive Ethernet myths and what actually breaks in real-world development and validation. From "Ethernet isn't deterministic" to "Ethernet will replace CAN," we'll separate fact from fiction and examine the challenges engineers actually encounter during development.

JSAE Show 2024

Wed, 08 May 2024 09:41:24 -0400

ATI at JSAE (Japan Society of Automotive Engineers) 2024

The JSAE conference is a showcase of innovation and collaboration for the Japanese automotive industry. With sustainability and efficiency at the forefront, the event provides a platform for Japanese engineers, researchers, and industry leaders to exchange ideas and insights into the future of mobility.

From cutting-edge advancements in electric vehicles to breakthroughs in autonomous driving technology, the JSAE show demonstrates the industry's relentless pursuit of excellence and its commitment to shaping a greener, safer, and more connected automotive landscape.

The ATI Japan team will show its commitment to cutting-edge technologies and solutions designed to address the industry's most pressing challenges with demonstration highlights at the event, offering attendees a firsthand glimpse into the company's transformative offerings:

Explore the intricate interplay of LIN and CAN messages, seamlessly interfaced with a PC using Kvaser Hybrid, exemplifying ATI's commitment to connectivity and interoperability.

Delve into the future of automotive connectivity as ATI demonstrates the conversion of LIN messages to Automotive Ethernet messages using VCG and AE-100, paving the way for enhanced data transmission and communication protocols.

Gain insights into system performance and diagnostics as live CAN messages are displayed on the DAS4ATI, while all messages across multiple automotive networks are meticulously monitored and logged in VISION 7.0 ECU Calibration and Data Acquisition software, underscoring ATI's commitment to data-driven decision-making and optimization.

Discover more about the JSAE show at: https://aee.expo-info.jsae.or.jp/en/yokohama/

Booth number: 182

Introducing the AE-1000 USB

Thu, 25 Apr 2024 13:53:46 -0400

Revolutionizing Automotive Ethernet Connectivity

In the area of automotive technology, connectivity is key. As vehicles become increasingly sophisticated, the need for seamless communication between various systems has never been more crucial. Enter the AE-1000 USB 3.0 Type C Automotive Ethernet Adapter—an innovative solution that bridges the gap between USB and Automotive Ethernet, paving the way for enhanced connectivity and communication in the automotive industry.

The AE-1000 USB is a bi-directional physical layer media converter that facilitates seamless communication between USB and Automotive Ethernet (OPEN Alliance BroadR-Reach). With its plug-and-play functionality, users can enjoy hassle-free connectivity without the need for any additional configuration software. Simply plug the AE-1000 USB into a USB port, and you're ready to go.

Powered via USB, the AE-1000 USB seamlessly integrates with standard NIC (Network Interface Card) drivers, installing as an Ethernet port on the PC. This means that users can leverage existing infrastructure and protocols, eliminating the need for specialized drivers or software. Whether you're a seasoned automotive engineer or a tech-savvy enthusiast, the AE-1000 USB offers a user-friendly solution for enhancing connectivity and communication in automotive applications.

Equipped with support for 100/1000Mbps data rates, the AE-1000 USB 3.0 transfers data up to 10 times faster compared to USB 2.0, ensuring smooth and efficient data transfer between systems. Whether you're transferring large datasets, streaming multimedia content, or conducting real-time diagnostics, the AE-1000 USB is up to the task, providing reliable connectivity when it matters most.

The AE-1000 USB offers customizable configuration options, allowing users to tailor the adapter to their specific needs. With configuration switches for Commander/Responder mode, data rate selection (1000Mbps or 100Mbps), auto-negotiation, and Gigabit-A0 (Legacy) or Gigabit-A2 (IEEE) compatibility, users have the flexibility to optimize performance based on their unique requirements. Whether you're looking for maximum speed or legacy compatibility, the AE-1000 USB puts the power in your hands.

With its innovative design, plug-and-play functionality, and customizable configuration options, the AE-1000 USB Automotive Ethernet Adapter is poised to revolutionize connectivity in the automotive industry. Whether you're developing next-generation vehicle systems, conducting diagnostics, or exploring new possibilities in automotive technology, the AE-1000 USB provides a reliable and efficient solution for enhancing communication and connectivity. Say goodbye to connectivity woes and hello to a future of seamless automotive communication with the AE-1000 USB.

USB 3.0 vs. 2.0

Mon, 19 Feb 2024 11:21:22 -0500

ATI’s AE1000 uses USB 3.0, offering faster/better options over its predecessors.

You may be comfortable and familiar with USB 2.0, but ATI is now launching an Automotive Ethernet adaptor (the AE-1000) with USB 3.0. What does this change signify? Well, you can step into the fast lane of data transfer with USB 3.0 – a technological leap that not only outpaces its predecessor by up to 10 times but also revolutionizes syncing and charging, providing an efficient power boost for mobile platforms.

So, let’s explore how this cutting-edge USB technology is reshaping the way we connect and power electronic devices. Firstly – speed. In optimal conditions USB 3.0 is up to 10 times faster on data transfer compared to USB 2.0.

Next, efficiency. USB 3.0 not only synchronizes data faster than its predecessor, but it also charges devices faster (at 900mA per USB 3.0 port,) meaning that it’s an excellent power management technology ideal for mobile platforms.

USB 3.0 is also compatibility agnostic. It’s backward compatible with both USB 1.1 and 2.0, ensuring seamless connectivity across various devices and avoiding unnecessary obsolescence. This enables users to opt for gradual upgrades to external devices, saving the costs of having to immediately replace them.

With regards power efficiency and output, USB 3.0 enhances the overall energy performance of connected devices and boasts an improved current (9A) output compared to USB 2.0’s 0.5A. This equates to 4.5 Watts from a standard 5V output, meaning that connected devices charge significantly faster.

Arguably the largest positive impact of USB 3.0 speeds lies in the efficiency and time savings it brings to various data-intensive tasks, making it an asset for users who prioritize speed and productivity. For example, if a 25-gigabyte Blu-ray film takes approximately 14 minutes to transfer using a USB 2.0 interface a USB 3.0 interface will transfer the same film in just 70 seconds, making it 10x faster.

With these faster speeds, files previously transferred using USB 2.0 can be in a fraction of the time, significantly improving efficiency. This enables USB 3.0 to provide seamless media streaming, with a smoother and uninterrupted experience. Faster data transfer facilitates quicker backups and syncing, reducing the time required for routine data management tasks.

USB 3.0 is capable of higher transfer rates due to utilizing five more pins than previously used in USB 2.0, which allows both the host and device to operate in dual channels. This enables a significantly faster data transfer than was possible using USB 2.0’s single-channel transmission which could only receive or transmit a single signal and often resulted in bottlenecks.

USB 3.0 can transfer up to 5 Gbps. For certain applications, especially those involving external storage or fast data transfer between devices, USB 3.0 may provide sufficient speed without the need for Ethernet infrastructure. This is a key user benefit because setting up USB connections is significantly simpler than configuring Ethernet connections. Typically, USB devices can be plugged in and recognized by a system without requiring additional network configurations.

Ethernet connections typically require additional hardware such as routers, switches, and cables to establish a network. USB 3.0 on the other hand, only requires compatible ports on the connected devices, making it far more user-friendly.

Hence why ATI’s new AE-1000 the incorporation of USB 3.0 offers a simple solution for higher speed devices. Its 9-pin DB connection accommodates Automotive Ethernet with speeds that can be matched by its new USB 3.0 technology without data bottlenecks. This enables the AE-1000 to behave as the perfect intermediate plug and play media converter product for connected devices still operating under 5Gbps, without requiring the complications of an external Ethernet network.