Open logger recordings in MATLAB
Bring CAN signals from MF4 bus-logging files into MATLAB as plain variables, without a toolbox for reading MDF files.
Convert MF4 (MDF4) to MAT or CSV in your browser.
Convert an MF4 (MDF4) bus log to MATLAB .mat or CSV, decoded with your DBC. No CANape or CANoe needed.
Step 1 of 4 · Upload logs
Drop your MF4 file here
or.mf4 files up to 150 MiB, up to 5 at a time. Conversion runs in your browser, so files stay on your computer.
Who ends up holding an MF4 they cannot open
MF4 (MDF4) is the ASAM standard that data loggers and measurement tools write. When it holds raw CAN traffic, the signals are readable only once a DBC has decoded them.
Export MF4 CAN data to CSV for Excel
Turn decoded CAN signals into one flat table for spreadsheets, dashboards or an attachment to a defect ticket.
Share measurements across teams and suppliers
Not everyone has CANape, INCA or an MDF4 viewer. MAT and CSV files open anywhere.
from scipy.io import loadmat
d = loadmat('drive.mat', squeeze_me=True,
struct_as_record=False)
# fields: time, value, unit
speed = d['ESP_VehicleSpeed']Feed Python and machine-learning pipelines
Load decoded signals with SciPy or pandas for statistics, regression analysis or training data from field tests.
Turn an MF4 recording into signals
Four steps. The MF4 file and your DBC files stay in your browser.
Add an MF4 bus-logging file
Drop up to five .mf4 files. Each is scanned for CAN bus-logging data and the channels it contains are listed.
Link each channel to its DBC
The frames in an MF4 are raw, so signals need a DBC. Connect each channel to its own database, either by dragging a DBC onto the channel or by adding more files.
Choose .mat or .csv
MAT stores a struct per signal for MATLAB; CSV gives a single table for Excel and Python.
Convert and download
Frames are decoded with your DBC and each MF4 is saved as its own .mat or .csv.
What an MF4 conversion hands back
Only signals decoded with your DBC are written, at full resolution, with time in seconds.
| time_s | time_us | channel | message | signal | value | unit |
|---|---|---|---|---|---|---|
| 0.004608 | 4608 | 1 | ESP | VehicleSpeed | 42.5 | km/h |
| 0.014595 | 14595 | 1 | ESP | VehicleSpeed | 42.6 | km/h |
| 0.024611 | 24611 | 2 | VCU | DrvTorReq | 118 | Nm |
The .mat structure
Each signal is a struct named Message_Signal with its time and value arrays; unit, message and channel travel with it. An info struct records the MF4 and its channels.
The CSV table
A flat table with time_s, time_us, channel, message, signal, value and unit, one row per sample, easy to filter in Excel or pandas.
Signals already stored in the MF4 are not copied
This tool decodes raw CAN frames. Measurement channels that already hold physical values, such as ECU signals recorded by a calibration tool, are not exported. Frames missing from your DBC are skipped too.
Per-run limits
Five MF4 files per run, each up to 150 MiB. A CSV holds 2,000,000 rows; use MAT for long recordings, which has no row limit.
MF4 conversion: what to know first
What does it take to convert an MF4 recording?
An MF4 with CAN bus logging and the DBC for each bus. Add the file, link every channel, choose MAT or CSV and convert. It runs in your browser and the output downloads from the page.
Which MF4 files will work?
ASAM MDF 4.x files that store raw CAN or CAN FD frames, that is, bus logging. If a file only contains measurement signals that are already physical values, there are no frames to decode.
Is MF4 the same thing as MDF4?
Yes. MDF4 is the ASAM Measurement Data Format, version 4, and .mf4 is its file extension.
Does my MF4 get uploaded?
No. The MF4 and your DBCs are read, decoded and written inside your browser tab.
Several CAN channels in one MF4: how do DBCs apply?
Link a DBC per channel. With two DBCs on one channel, each frame goes to the first linked DBC that defines its ID and the second covers only the rest; nothing is merged or repeated.
The converted file is empty. What happened?
Most often the DBC does not belong to that bus, or a channel has no DBC linked. Link the database that defines the messages on each channel. An MF4 that only holds decoded signals has no CAN frames to convert.
Can I export CSV for Excel, and what are the limits?
Yes, choose CSV. A CSV is capped at 2,000,000 rows, so long recordings fit better in MAT. Each MF4 may be up to 150 MiB, five per run.
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