CAN Scope

A portable Windows application for loading automotive measurements, decoding CAN signals (.mf4, mdf, .blf, .asc,.csv) , inspecting raw frames, and plotting signal data interactively.

Screenshots

Stacked plot:

Multiple Axis plot:

CAN Trace / Raw Frame viewer:

Supported formats

Measurement	Content	Database
BLF (.blf)	Raw CAN frames	DBC or ARXML required
ASC (.asc)	Raw CAN frames	DBC or ARXML required
MDF4/MDF3 (.mf4, .mdf)	Raw CAN bus logging or pre-decoded signals	Required only for raw bus logging
CSV (.csv)	Raw CAN export, narrow signals, or wide signals	Required only for raw CAN data

MDF and CSV content is detected automatically. Database Manager supports per-channel DBC/ARXML assignments, mixed database formats, decode-coverage indicators, and a channel-0 fallback.

Current capabilities

• Fast bulk loading and decoding for BLF, ASC, MDF/MF4, and CSV measurements.
• Searchable channel/message/signal tree with multi-select plotting and drag-and-drop.
• Indexed CAN Trace viewer for raw frames, filtering, and on-demand signal decode.
• Formula-based New Signal generation with arithmetic, comparisons, and logical expressions; generated definitions are saved in configurations.
• CSV and Excel (.xlsx) export of plotted signals on a shared time axis.
• JSON configuration save/load for measurement paths, database mapping, generated signals, plotted order, groups, colors, visibility, axes, cursors, and display settings.
• YAML rule-based diagnostics for expressions, ranges, fault flags, and message loss; optional GitHub Models analysis is available through Ctrl+Shift+A.

Plotting

• Stacked is the default mode and gives each signal its own lane and Y scale.
• Normal overlays signals on one Y axis.
• Multi-Axis groups axes by unit, with an optional individual axis per signal.
• Dual draggable cursors provide values and delta time.
• Fit-to-window and vertical-fit work across all plot modes while preserving the relevant view range.
• Signals can be grouped, reordered by dragging, recolored, hidden, or removed.
• Show Data Points uses adaptive markers and thinner lines.
• Hide Line is enabled only when data points are shown; when ON, it displays points without signal lines.

Install and run

Portable release

Download the latest Windows ZIP from Releases, extract it, and run CANScope.exe. No installer or Python installation is required.

From source

git clone https://github.com/dinacaran/canscope.git
cd canscope
python -m venv .venv
.\.venv\Scripts\Activate.ps1
python -m pip install -r requirements.txt
python app.py

The portable build and CI release build use Python 3.12.

Basic workflow

1. Select Open File and choose a supported measurement.
2. If the file contains raw CAN frames, select Open Database and configure DBC/ARXML mapping.
3. Select Load + Decode.
4. Search the signal tree, then double-click, drag, press Space, or use the context menu to plot signals.
5. Use cursors, plot modes, data points, grouping, and fit controls as needed.
6. Select Save Config to preserve the session or Export to write CSV/Excel data.
7. Open CAN Trace when the source contains raw CAN frames.

Keyboard shortcuts

Key	Action
F	Fit X and Y to all visible data
V	Fit Y to the current X range
Space	Plot selected signal-tree entries
C	Change the selected signal color
R	Toggle both cursors
Delete	Remove selected plotted signals
Ctrl+Z	Undo the last plot action
Ctrl+S	Save configuration
Ctrl+Shift+R	Open CAN Trace
Ctrl+Shift+- / Ctrl+Shift++	Collapse / expand signal-tree messages

Test and build

python -m pip install -r requirements.txt -r requirements-dev.txt
python -m pytest

Build the portable application with:

.\build_portable.bat

Output is written to dist\CANScope\. Pushing a v*.*.* tag runs the Windows build workflow and publishes a release ZIP.

Repository layout

app.py                 Application entry point and version
core/readers/          BLF, ASC, MDF/MF4, and CSV readers
core/                  Decode, signal storage, export, and generated-signal logic
core/diagnostics/      Rule engine and optional AI-assisted diagnostics
gui/                   Main window, plots, database manager, CAN Trace, diagnostics
config/diagnostics/    User-editable diagnostic rules and documentation
resources/             Application icon and splash assets
tests/                 Pytest regression suite

Runtime dependencies are maintained in requirements.txt.

Security and license

Release binaries are currently unsigned, so Windows SmartScreen may show a warning on first launch.

CAN Scope is licensed under the MIT License.