Logging & Replay

CANoli can record everything on the bus to a file and later replay it as if it were live traffic. Both live in the Logger panel (the record icon in the sidebar).

The Logger panel, with the recording controls above the replay controls

Recording a log

  1. Connect to the bus.
  2. Open the Logger panel.
  3. Choose a Format from the dropdown:
    • ASC — Vector ASCII format, widely interoperable.
    • BLF — Vector binary format, compact for large captures.
    • CSV — plain spreadsheet format.
  4. Click Start Logging. The button changes to Stop Logging and the status reads Logging....
  5. Click Stop Logging when you’re done.

While recording, the panel’s Frames: count and file Size: tick live, and the status bar’s logging label counts up with them — so you can see capture progressing even with the Logger panel closed.

Logs are written to a logs/ folder next to your project file, with timestamped names like canoli_20260617_143022.asc. The Saves to: line shows the folder — hover it for the full path, or click the copy button beside it to put the path on the clipboard.

Markers

Type a note in the Marker text… field and click Add Marker to drop a timestamped annotation into the log while recording — handy for marking the moment a fault occurred.

Loading a log for replay

In the Replay section of the Logger panel:

  1. Click Open Log File… and pick a log. Replay can read ASC (.asc), BLF (.blf), CSV (.csv), and TRC (.trc, PEAK) files.
  2. The progress readout shows Replay: 0 / <total> once the file is loaded.

Playing back

The replay controls are:

  • Play — start replaying; the button becomes Pause while running.
  • Reset — rewind to the first frame.
  • Step — advance a single frame at a time (great for inspecting a sequence).
  • Speed: — playback rate: 1x (original timing), 2x, 5x, 10x, or Max (as fast as possible).

As replay runs, the progress readout updates (for example, Replay: 42 / 1000) and the replayed frames flow into the Trace window and Chart exactly like live traffic — so every analysis tool works on recorded data too.

Tip: Replay is also the easiest way to feed a log into the AI features. Most AI tools read a log file directly, so you can analyze a capture without going on bus at all.

Next: Charting Received Data.