ros2-examples-ads

Example ROS2 package for communicating with Beckhoff PLC´s using ADS/AMS.

ADS - Automation Device Specification
AMS - Automation Message Specification

See also: https://infosys.beckhoff.com/content/1033/tc3_ads_intro/116158859.html

Tested using Ubuntu 22.04.2 LTS.

Build instructions for ADS library (do this first):

1. Navigate to a suitable location, for example cd ~/projects/.
2. Clone the project including submodules in your selected location:
   git clone --recurse-submodules [email protected]:kristianmk/ros2-examples-ads.git. (or https://github.com/kristianmk/ros2-examples-ads.git)
3. If the next step fails, you need a specific ADS library version (the submodule is by default the newest one, and this could be wrong in the future!).
4. Go to the ADS subfolder; build the ADS library. Build as described in the ADS library README-file: First meson build then ninja -C build. Error-like message "Library ws2_32 found: NO" is OK when we are running meson build on Linux, as ws2_32 is the MS Windows sockets library (we don´t need/want that anyways).
5. Go back to the main ros-examples-ads folder.

The Beckhoff ADS library is available here if you prefer not to use submodules: https://github.com/Beckhoff/ADS .

Build instructions for ADS example without ROS2. This example is more or less identical to the official Beckhoff example program:

1. Navigate to the ads_example_cmake_no_ros2 folder.
2. Edit the ADS example to reflect a correct remote IP and remote AMS net id.
3. Open CMakeLists.txt and look at how it builds the ADS library without depending on the git submodule for better automating the build. (We did not need to build the ADS module separately before this).
4. Run cmake . then make.
5. Test the ads_example program.

Build instructions for ROS2 node example:

0. Make sure you have ROS2 installed.
1. Navigate to the ads_example_package folder.
2. Edit the ADS example to reflect a correct remote IP and remote AMS net id.
3. Source ROS2 underlay (for example if using a bash terminal and a custom built ROS2:
   . ~/ros2_humble/install/local_setup.bash.
4. Note that this ROS2 package example will NOT build the ADS library automagically. The next step will fail if you did not build it in the ADS submodule directory earlier.
5. Build using colcon build.
6. Source ROS2 overlay (for example, if using a bash terminal: . install/local_setup.bash.
7. Run the node with ros2 run ads_example_package ads_node.

Exception handling was not included in this example; all ADS operations that could throw exceptions should be handled; see error handling in the ADS example without ROS2 from Beckhoff. See https://isocpp.org/wiki/faq/exceptions#why-exceptions to understand why you should know exceptions in C++.