ros2_control SystemInterface test

Test details

Tests
Detail	Information
Package	canopen_ros2_control
Test file	launch/canopen_system.launch.py
Description	Create an exemplary ros2_control SystemInterface with CAN master and communicates to a slave node.
Prerequisites	vcan0 must be available

Explanation of the test

The test is starting generic system interface and generic controller for CanOpen devices. Generic system interface enables integration of values from the CAN Bus into ros2_control framework and the controller enables you to send and receive data from the CAN bus through ros2_control to ROS2.

The next few lines show you some command to have exemplary usage of the ros2_control integration:

After the test is started check /dynamic_joint_states to show internal data from CAN nodes in ros2_control system.
```
ros2 topic echo /dynamic_joint_states
```
Open a new terminal and echo data from the topic /node_1_controller/rpdo.
```
ros2 topic echo /node_1_controller/rpdo
```
In a new terminal publish some data to the controller to write them to the CAN bus:
```
ros2 topic pub -r 100 node_1_controller/rpdo canopen_interfaces/msg/COData "
  index: 25
  subindex: 35
  data: 238
  type: 8"
```
Now watch how data in the first two opened terminals are changing.