Connecting a Robot
After assembling and installing the robot and control unit as detailed in the user manual, power on the control unit. It can take a couple of minutes for the controller software to fully start up.
Connecting a PC to the Control Unit
Connect the computer running ROS 2 to the PC port on the control unit.
Attention
For the time being, ensure that there is only one connection path between the control unit and the ROS 2 PC. Simultaneous connections on multiple network interfaces (e.g. via PC port and via another local network) have been observed to cause problems with ROS 2 communication. This issue will be addressed in a future version of the RobCo ROS 2 interface.
The PC will be assigned an IP address in the 192.168.3.0/24 subnet (i.e. IP addresses will be of
the form 192.168.3.x). Thus, the PC should be configured for automatic IP assignment via DHCP.
To verify the connection to the control unit, the ping command can be used with the control unit’s
interface address on the PC port, 192.168.3.1:
$ ping 192.168.3.1
PING 192.168.3.1 (192.168.3.1) 56(84) bytes of data.
64 bytes from 192.168.3.1: icmp_seq=1 ttl=64 time=0.818 ms
64 bytes from 192.168.3.1: icmp_seq=2 ttl=64 time=1.08 ms
If there are no replies to the ping command, please refer to the Network Troubleshooting section below.
Verify ROS Connection
To verify that the robot controller software has fully started up, open a browser on the ROS PC and
navigate to http://192.168.3.1. Acknowledge any warnings from the browser, the RobFlow interface
does not have SSL (HTTPS) support. Verify the controller connection by clicking the status icons on
the top right.
If the controller is started up and connected, the ROS 2 connection can now be verified:
ros2 topic list
The output should contain the /robco_joint_states and /robco_joint_commands topics. To verify
that messages are actually received:
ros2 topic echo /robco_joint_states
If messages with the current joint angles and velocities are displayed, the ROS 2 interface is operating correctly.
Network Troubleshooting
No Connection to Control Unit
If the connection from PC to control unit could not be established (no reply to ping command), here are some troubleshooting steps:
Verify that the control unit is indeed powered on.
Check the activity LEDs (if present) on the PCs network port are lit up. If not, try exchanging the network cable.
Verify in the PC’s network settings that automatic IP assignment via DHCP is enabled.