Logger User Guide

The Logger records CAN bus data for later analysis, export, and playback. It provides a full view of stored data including disk usage, recording sessions, user events, and partition management.

Logger Overview

Logger page showing disk usage card and stored data partitions card with Overview tab active

The Logger page has two main sections:

Disk Usage Card — Storage metrics for the logging system
Stored Data Partitions Card — Two tabs for viewing recorded data

Click Refresh to update the displayed data manually.

Disk Usage

Disk usage card showing used space, free space, total space, and progress bar

The disk usage card displays:

Metric	Description
Used Space	Storage consumed (with percentage of total)
Free Space	Available storage (highlighted in green)
Total Space	Total disk capacity

A visual progress bar shows the current usage level.

Overview Tab

Overview tab showing logger sessions chart on the left and user events table on the right

The Overview tab displays recording sessions and user events side by side.

Time Range Inputs

The Start and End fields at the top are editable text inputs in 24-hour format (YYYY-MM-DD HH:MM:SS). Type directly to set a precise time range for viewing and exporting data. The start time cannot be set later than the end time. These fields update automatically when navigating the chart or selecting events.

Logger Sessions Chart

Bar chart visualization of logging sessions
Each bar represents a recording session with start/stop timestamps
Click a bar to highlight its corresponding user events

User Events Table

Column	Description
Time	Full timestamp (YYYY-MM-DD HH:MM:SS)
Topic	Event category
Payload	Event data or message
#	Session number badge

Features:

Search — Filter events by topic or payload
Click a row to highlight the associated session
Clear button to remove highlight

Session Summary Stats

Four statistics at the bottom:

Stat	Description
Sessions	Total number of recording sessions
Total CAN1	Total CAN1 frames recorded
Total CAN2	Total CAN2 frames recorded
Total Frames	Combined total across both channels

Advanced Tab

Advanced tab showing partition bar chart with data zoom slider and stored partitions count

The Advanced tab provides detailed partition-level storage visualization.

Partition Bar Chart

X-axis: Date/time labels for each partition group
Y-axis: Logarithmic scale showing data point counts (formatted as K/M)
Hover over bars to see partition details
Click a bar to open the Partition Details modal
Slider at the bottom for zooming into large datasets

Partition Details

Partition Details modal showing time period, partition table with checkboxes, and action buttons

Click a bar in the Advanced tab to open the Partition Details modal.

Group Summary

Time Period — Start and end time of the partition group
Total Data Points — Total frames with count of underlying partitions
Selected Partitions — Number selected for export or removal

Partition Table

Column	Description
Start Time	Partition start timestamp
End Time	Partition end timestamp
Duration	Formatted as hours, minutes, seconds
Data Points	Number of CAN frames
Select	Checkbox for bulk operations

Action Buttons

Button	Description
Select All / Deselect All	Toggle selection of all partitions
Export Selected	Download selected partitions (choose CSV or Candump format)
Remove Selected	Delete selected partitions (with confirmation)
Close	Close the modal

Exporting Data

Export progress modal showing spinner, frames processed counter, and data size

Export Workflow

Click a partition bar in the Advanced tab (or a session in the Overview tab)
Select specific partitions using checkboxes
Click Export Selected
Choose a file location
Monitor real-time progress:
- Frames Processed counter
- Data Processed size
When complete, a success message confirms the export

Export Format

A Format dropdown lets you choose between:

Format	Description
CSV	Helix CSV format (Timestamp, Ch, ID, DLC, Flags, Data). Best for spreadsheet analysis.
Candump (.txt)	Standard Linux `candump -l` format. Compatible with `canplayer`, `cansniffer`, and other SocketCAN utilities.

Files are named can_export_YYYY-MM-DDTHH-mm-ss-sssZ.csv (or .txt for candump)
Large exports are split into multiple files (10M frames per file)

Warning: Do not close the browser window during export.

Removing Partitions

Removal confirmation dialog with warning about permanent data deletion

Removal Workflow

Select partitions using checkboxes
Click Remove Selected
Confirm in the dialog — this action cannot be undone
Monitor removal progress
Data refreshes automatically after completion

Starting and Stopping Recording

Recording can be started from multiple locations:

Dashboard toolbar — Play/Stop buttons control live data and recording
Logger Quick Access — Toggle in the header toolbar
Logger Settings — Configure auto-start on boot

When recording is active, the sidebar shows a REC indicator.

User Events

User events are timestamped markers that can be created from anywhere in the application:

Click the Create User Event button in the header toolbar
Simple mode — Enter just a message
Advanced mode — Provide a custom topic and JSON payload

Events appear in the Overview tab's User Events table and are associated with recording sessions.

Tips

Monitor disk usage — Keep an eye on free space, especially during long recording sessions
Export before deleting — Always export important data before removing partitions
Use user events — Mark important moments during recording for easier analysis later
Enable auto-start — Configure auto-start logging in Settings > Logger for unattended recording
Use time range exports — When exporting from the Overview tab, adjust the time range to select specific data windows