What is an MF4/MDF4 file?

Measurement Data Format version 4 (MDF 4) is a standard file format by ASAM used by the automotive industry for storing measurement data in binary file format. It records CAN, CAN FD, LIN bus data, sensor data from an engine control unit (ECU), offering interoperability across many CAN tools. It contains both the raw measurement data and the metadata necessary to interpret that raw data.

MDF first came into existence in the ’90s, when it was developed by Bosch and was later made public in 2002. Later ASAM standardized it in 2009. MDF4 is the latest version extensively used in CAN software APIs and has become the widely used standard across the automotive industry.

It enables one to store the recorded or calculated data for post-measurement processing, evaluation and long-term storage. But these are not the only advantages of using the MDF4 format.


  • Supports raw bus logging and physical values.

  • Open standard with comprehensive support for CANbus logging.

  • Designed to be fast. As it is index base hence, extremely fast to read, write, edit etc.

  • Enables loss-less recording.

  • Used for data exchange between different tools

  • It supports compressions, which drastically reduces the file size, thus improving the SD card capacity, server cost, and 3G/4G upload expenses.

  • Allows files of any size to be written (264 bytes).

  • Supported by many powerful and free software and APIs.

MDF4 Blocks Structure

An ASAM MDF file (file extension: *.mf4) is organized in binary blocks where each block consists of several contiguous bytes that can be seen as a record or structure of data fields. There are different types of blocks, and the block type defines the block’s purpose and content.

CAN data Frame Blocks.PNG

Further, the CN 2 (signal) or CAN Data Frame. This is split into seven parts/sub channels:

CAN Data Frame.png
CAN Data Frame channels.PNG

These features make MDF ideal for cloud analytics and telematics - across CAN, CAN FD, LIN, J1939, OBD2, CANopen, NMEA 2000 and more. ‘DiaLog’ and ‘ReXdesk’ software from Influx support MDF4 formats for storing data. In addition to MDF4, we support various other formats such as MAT, CSV, S3T, TDM, ASC, BLF, TRC.

For detailed information on this, please visit: https://www.asam.net/standards/detail/mdf/wiki/

To know more on Influx Technology & its MF4 compatible loggers, Click here.