SOEM for ROS2

Table of Contents

• SOEM ROS2 Package Upgrade
• Package Description
• Installation
• Building the package
• Usage

SOEM ROS2 Package Upgrade

This package is a thin ROS2 wrapper of the Simple Open EtherCAT Master (SOEM). It is based on the ROS1 wrapper from http://wiki.ros.org/soem https://github.com/mgruhler/soem. The main difference is that ROS2 uses the colcon build system, and ROS1 the catkin build system. This package allows you to use soem from within your regular ROS2 workspace.

Package Description

SOEM is an open source EtherCAT master library written in C.

SOEM has originally been hosted at http://developer.berlios.de/projects/soem/ but has been moved to GitHub and the OpenEtherCATsociety organisation.

Disclaimer: This package is not a development package for SOEM, but rather a wrapper to provide SOEM to ROS2.

All bug reports regarding the original SOEM source code should go to the bugtracker at https://github.com/OpenEtherCATsociety/SOEM/issues.

All ROS related issues may not be adressed. I put it out here in the hope that someone else will maintain it, so basically it is what it is.

Installation

You have to build soem by building this package because there is no ros--soem binary available.

Building the package

Create workspace

First create a ROS2 workspace, including a src-directory.

Then goto the src-directory and clone this repository.

Clone a repository

Use these steps to clone from SourceTree, our client for using the repository command-line free. Cloning allows you to work on your files locally. If you don’t yet have SourceTree, download and install first. If you prefer to clone from the command line, see Clone a repository.

1. You’ll see the clone button under the Source heading. Click that button.

2. Now click Check out in SourceTree. You may need to create a SourceTree account or log in.

3. When you see the Clone New dialog in SourceTree, update the destination path and name if you’d like to and then click Clone.

4. Open the directory you just created to see your repository’s files.

Build

Go back to the workspace directory. Bulld using:

colcon build

Usage

To use soem in your ROS2 package add the following to your package.xmland CMakeLists.txt, respectively.

In your package.xml add:

  <depend>soem</depend>

and in your CMakeLists.txt, add it to find_package as shown:

find_package(soem REQUIRED)

Better yet, there is an example application ether_ros2 that is a simple ROS2-node in which some analog values are polled. It is advised to observe the code including the package.xmland CMakeLists.txt for your convenience.