eCAL - enhanced Communication Abstraction Layer

The enhanced Communication Abstraction Layer (eCAL) is a middleware that enables scalable, high performance interprocess communication on a single computer node or between different nodes in a computer network. eCAL provides publish - subscribe and server - client pattern to connect different nodes in the network with almost no configuration required.

eCAL automatically chooses the best available data transport mechanism for each link, it supports: - Shared memory for local communication (incredibly fast!) - UDP and TCP for network communication

Visit the eCAL Documentation at 🌐 https://ecal.io for more information.

Architecture

Facts about eCAL

• eCAL is fast (1 - 20 GB/s, depends on payload size. Check the measured performance here)
• eCAL provides both publish-subscribe and server-client patterns
• eCAL is brokerless
• eCAL provides a C++ and C interface for easy integration into other languages (like python, csharp or rust)
• eCAL can be used in conjunction with Matlab Simulink as eCAL Simulink Toolbox for simulation and prototyping
• eCAL has powerful tools for recording, replay and monitoring all your data flows - decentralized
• eCAL is simple and zero-conf. No complex configuration for communication details and QOS settings are needed
• eCAL is message protocol agnostic. You choose the message protocol that fits to your needs like Google Protobuf, CapnProto, Flatbuffers...
• eCAL uses the standardized recording format HDF5
• eCAL integrates gently into your ROS2 environment with the eCAL RMW

• eCAL supports Intel and arm platforms

• eCAL runs on a wide variety of operating systems:

  • Windows (stable)
  • Linux (stable)
  • QNX (experimental)
  • MacOS (experimental)
  • FreeBSD (experimental)

Installation

We provide binary installers for Windows and Ubuntu. If you need further help installing and configuring eCAL, please refer to the documentation.

Windows

Download the latest eCAL Installer and follow the Setup Wizard

We only support 64bit Windows 7 / 10

Ubuntu

Install eCAL from our PPA:

sudo add-apt-repository ppa:ecal/ecal-latest
sudo apt-get update
sudo apt-get install ecal

This PPA will always upgrade you to the latest eCAL Release (-> Rolling Release PPA). If you intend to stay on an specific release, check out other PPAs here.

Ubuntu 18.04, 20.04, 22.04, 23.04, 23.10 for CPU architectures (i386), x64, armhf, arm64 are supported at the time of writing.

Example

Using eCAL in your project to exchange data is simple. After you have downloaded eCAL and installed CMake, you are good to go.

Check out the Hello World example from the eCAL documentation for further details.

#include <ecal/ecal.h>
#include <ecal/msg/string/publisher.h>

#include <thread>

int main(int argc, char** argv)
{
  // Initialize eCAL. The name of our process will be "Hello World Publisher"
  eCAL::Initialize(argc, argv, "Hello World Publisher");

  // Create a String Publisher that publishes on the topic "hello_world_topic"
  eCAL::string::CPublisher<std::string> publisher("hello_world_topic");

  // Infinite loop
  while (eCAL::Ok())
  {
    // Publish a "Hello World" message
    publisher.Send("Hello World");

    std::this_thread::sleep_for(std::chrono::milliseconds(500));
  }

  // finalize eCAL API
  eCAL::Finalize();
}

Tools from the eCAL ecosystem

eCAL comes with a set of read-to-use tools that will help you with developing, testing and debugging your software. Command line interface versions and easy to use GUI applications are available.

• The eCAL Monitor to visualize the data flow and inspect messages sent between publishers and subscribers

• The eCAL Recorder to record the data sent between your eCAL nodes

• The eCAL Player to replay the eCAL recordings later on

• eCAL Sys to define your system configuration and monitor your applications

eCAL eco system tools / utilities / interfaces

• ecal-toolbox - Mathworks simulink toolbox for eCAL
• ecal-mongraph - Simple graph visualization for eCAL
• ecal-gpsd-client - eCAL gpsd client

eCAL & Foxglove

• ecal-foxglove-bridge - Visualize eCAL messages with Foxglove Studio
• ecal-mcap-tools - Interoperability tools between eCAL HDF5 and MCAP measurement format

eCAL & ROS

• rmw_ecal - eCAL / ROS2 middleware layer
• rosidl_typesupport_protobuf - Protobuf based rosidl typesupport

Other projects related to eCAL

• fineftp-server - FTP functionality to collect distributed measurement artifacts over network
• tcp_pubsub - Additional TCP transport layer for higher reliability for publication/subscription over network
• udpcap - Npcap based UDP-socket emulation to increase the eCAL performance on MS Windows
• docker-ecal - Inoffical dockerfiles for eCAL
• golang-ecal - eCAL go language binding
• ecal-rs - eCAL rust language binding
• nodejs-ecal - eCAL wrapped for Nodejs
• trellis - General purpose middleware framework for distributed applications
• ADMA2eCAL - Software gateway for connection to ADMA hardware from GeneSys Elekronik GmbH

License

eCAL is licensed under Apache License 2.0. You are free to

• Use eCAL commercially
• Modify eCAL
• Distribute eCAL

eCAL is provided on an “as is” basis without warranties or conditions of any kind.

Contributors

How to contribute

This repository is maintained by the Eclipse Foundation, Inc.

Contributions via pull requests are very welcome! Please discuss a change you wish to make via issue (preferred), email, or any other method with the maintainers of this repository.

Ways you can help

• Code reviews: You can help with code review to avoid bugs and increase readability. Be welcoming, appreciative, and helpful.
• Communication in issues: You can monitor issues and help other people who have questions about contributing to, or using this project.
• Suggesting improvement: If you have a suggestion of your own, search the open issues. If you don't see it, feel free to open a new issue.
• Contributing solutions: Concrete solution proposals are very welcome. Have a look at the pull request description for further details.

Feel free to reach out to one of the maintainers if you need help getting started (see also below).

Pull Request Process

Code contributions are to be submitted via pull requests. For this fork this repository, apply the suggested changes and create a pull request to integrate them. Before creating the request, please ensure the following which we will check besides a technical review:

• No breaks:
  • Builds: All required platform builds pass (github actions).
  • Tests: The unit tests still pass.
  • Docs: The documentation still builds.
• Docs updated: Make sure any changes and additions are appropriately included into the documentation (both docstrings and the docs sources).
• The new code and included third party libraries do not infringe any trademark, patent, copyright, or open source compliance.
• Please make sure to sign the Eclipse Contributor Agreement and link your GitHub Account to your Eclipse Account.

Once we received your pull request, you will get feedback from the maintainers within 10 working days. Once you have the sign-off of at least one maintainer you may request the second reviewer to merge the Pull Request for you.

We are looking forward to your contributions.

Getting Help

1. If you're new to the project, a good place to start is the README.md and the quickstart section in the documentation linked in this project (alternatively, check out the documentation build instructions).
2. Take a look at the user guide and API documentation.
3. If you need help getting started or implementing a change, open an issue with your question. If there is already an issue open for the feature you're working on, please post there.

Code of Conduct

(The following is adapted from the Contributor Covenant, version 1.4, available at http://contributor-covenant.org/version/1/4)

Our Pledge

In the interest of fostering an open and welcoming environment, we as contributors and maintainers pledge to making participation in our project and our community a harassment-free experience for everyone, regardless of age, body size, disability, ethnicity, gender identity and expression, level of experience, nationality, personal appearance, religion, or sexual identity and orientation.

Our Standards

Examples of behavior that contributes to creating a positive environment include:

• Using welcoming and inclusive language
• Being respectful of differing viewpoints and experiences
• Gracefully accepting constructive criticism
• Focusing on what is best for the community
• Showing empathy towards other community members

Examples of unacceptable behavior by participants include:

• The use of sexualized language or imagery and unwelcome sexual attention or advances
• Trolling, insulting/derogatory comments, and personal or political attacks
• Public or private harassment
• Publishing others' private information, such as a physical or electronic address, without explicit permission
• Other conduct which could reasonably be considered inappropriate in a professional setting

Our Responsibilities

Project maintainers are responsible for clarifying the standards of acceptable behavior and are expected to take appropriate and fair corrective action in response to any instances of unacceptable behavior.

Project maintainers have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, or to ban temporarily or permanently any contributor for other behaviors that they deem inappropriate, threatening, offensive, or harmful.

Scope

This Code of Conduct applies both within project spaces and in public spaces when an individual is representing the project or its community. Examples of representing a project or community include using an official project e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event. Representation of a project may be further defined and clarified by project maintainers.

Enforcement

Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team. All complaints will be reviewed and investigated and will result in a response that is deemed necessary and appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.

Project maintainers who do not follow or enforce the Code of Conduct in good faith may face temporary or permanent repercussions as determined by other members of the project's leadership.