Overview

The diagnostics system collects information about hardware drivers and robot hardware to make them available to users and operators. The diagnostics system contains tools to collect and analyze this data.

The diagnostics system is build around the /diagnostics topic. The topic is used for diagnostic_msgs/DiagnosticArray messages. It contains information about the device names, status, and values.

It contains the following packages:

• diagnostic_aggregator: Aggregates diagnostic messages from different sources into a single message.
• diagnostic_analysis: Not ported to ROS2 yet #contributions-welcome
• diagnostic_common_diagnostics: Predefined nodes for monitoring the Linux and ROS system.
• diagnostic_updater: Base classes to publishing custom diagnostic messages for Python and C++.
• self_test: Tools to perform self tests on nodes.

Collecting diagnostic data

At the points of interest, i.e. the hardware drivers, the diagnostic data is collected. The data must be published on the /diagnostics topic. In the diagnostic_updater package, there are base classes to simplify the creation of diagnostic messages.

Aggregation

The diagnostic_aggregator package provides tools to aggregate diagnostic messages from different sources into a single message. It has a plugin system to define the aggregation rules.

Visualization

Outside of this repository, there is rqt_robot_monitor to visualize diagnostic messages that have been aggregated by the diagnostic_aggregator.

Diagnostics messages that are not aggregated can be visualized by rqt_runtime_monitor.

Target Distribution

• Rolling Ridley by the ros2 branch
• Humble Hawksbill by the ros2-humble branch
• Iron Irwini by the ros2-iron branch
• Jazzy Jalisco by the ros2-jazzy branch

Workflow

New features are to be developed in custom branches and then merged into the ros2 branch.

From there, the changes are backported to the other branches.

Backport Tooling

This tool has proven to be useful: backport

Use this command to port a given PR of PR_NUMBER to the other branches:

backport --pr PR_NUMBER -b ros2-humble ros2-iron ros2-jazzy

Versioning and Releases

• (X.0.0) We use the major version number to indicate a breaking change.
• (0.Y.0) The minor version number is used to differentiate between different ROS distributions:
  • x.0.z: Humble Hawksbill
  • x.1.z: Iron Irwini
  • x.2.z: Jazzy Jalisco
  • x.3.z: Rolling Ridley
  • Future releases (Kilted Kaiju 05/25) will get x.3.z and Rolling will be incremented accordingly.
• (0.0.Z) The patch version number is used for changes in the current ROS distribution that do not affect the API.

License

The source code is released under a BSD 3-Clause license.