MDF / MF4¶

Measurement Data Format for time-series measurement data and metadata.

Identity¶

Measurement Data Format for time-series measurement data and metadata.

What This Protocol Teaches¶

• Capture files are evidence containers with time bases and metadata.
• MDF meaning depends on channel metadata, conversions, and acquisition provenance.
• Logged signal values are not the same as live bus frames.

Operational Context¶

MDF / MF4 appears in automotive, measurement contexts and is modeled in the atlas at the capture-format layer(s). The binder treats it as an inspection surface: what evidence appears, what timing matters, and what outside authority is required before assigning meaning.

A Concrete Artifact¶

# synthetic MDF/MF4-like summary
DG0/CG0 time[s]: 0.000, 0.010, 0.020
Channel EngineSpeed[rpm]: 998.5, 1000.0, 1001.0
Source: decoded CAN signal via example.dbc

Synthetic offline sample for explanation; not a real operational trace or live-system instruction.

Worked Decode¶

1. Read DG0/CG0 time[s] as sampled-channel timing evidence in a synthetic file summary.
2. EngineSpeed[rpm] appears already decoded, so channel metadata and conversion provenance become the main authority.
3. Source: decoded CAN signal via example.dbc keeps the derived value tied to its description source.
4. An MDF/MF4 channel can preserve values while obscuring whether original bus timing or raw frames are still available.

Field Layout / Anatomy¶

Visual Model¶

Timing And Authority¶

Timing authority comes from acquisition clocks, time channels, synchronization, and file provenance. Semantic authority comes from channel metadata, conversions, and any upstream decode source.

Bytes rarely explain themselves. Name the source that defines meaning before naming engineering values: standard metadata, label table, DBC, PGN/SPN definition, object dictionary, register map, DID catalog, LDF, ARXML, channel metadata, or vendor profile.

Failure And Ambiguity¶

• Derived channels can look authoritative while hiding conversion provenance.
• Sample timing is file timing unless raw bus timing is explicitly preserved.
• Channel names can outlive the database or firmware version that created them.

Observer Lesson¶

An observer can infer sample cadence, gaps, alignments, channel provenance, and derived-state hypotheses. They cannot assume live bus timing or original wire evidence unless the file records it explicitly.

Python Model¶

schoolbus does not parse this format in this wave. This page records source posture, passive inspection questions, and metadata boundaries only. Runtime support would require a separate approved plan with concrete synthetic artifacts, tests, and source-checked parser boundaries.

Local Teaching Notes¶

The summary is synthetic and omits MDF block-level details.

Source Confidence¶

Source confidence is high for scope and terminology, with semantic claims limited to public metadata, public source notes, and synthetic teaching artifacts.

Source Notes¶

References¶

Public Sources¶

• ASAM
• ASAM MDF — canonical-standard.
• ASAM standards overview — official-public.
• Tooling references
• asammdf — MDF/MF4 files.