Problem with ROS terminal, joint plot and spiketrain in web cockpit


Hi, I’m new to the platform, so bear with me if this might be some basic error on my part.

The problem is this: I have a local install of the nrp, can launch experiments and enter the web cockpit. The experiments themselves run as they should, but neither the ROS terminal, joint plot nor the spiketrain visuals seem to work. More specifically

ROS terminal: The only command I can run is help. All other hang the terminal and give no output. On the other hand, ROS seems to work, since I can enter all commands in a local terminal, and from what I can see they give the expected outputs.

Joint plot: Opening the joint plot only shows “Start the simulation to display the plot”, even though the experiment is running, and joints are certainly moving.

Spiketrain: This simply displays an empty plot.

My guess is that all of these might be related to the fact that simulation time and real time are also not displayed in the web cockpit. This is the case for all experiments, both template and custom ones. Note that when I echo the /clock topic in a local terminal it shows that time is running.

Any ideas on what might be wrong? Help in any shape or form would be greatly appreciated. Let me know if I should provide any additional information.

Best regards,


Dear Oskar,

What seems to be broken here is Rosbridge. This component forwards ROS topics to a websocket for use by the Web cockpit. Test if this component is broken: check the output of it when you restart the backend with “cle-start” or stop the NRP, start only roscore and then cle-rosbridge and see.
Might also be nginx failing to forward rosbridge to port 8080. Original rosbridge port is 9090 and nginx is tunnelling it to 8080. See $HOME/.local/etc/nginx/conf.d/nrp-services.conf to see the config. Could be that 8080 is used on your PC?
Are you using a docker install or did you compile from sources?



Dear Axel,

Thanks, you are indeed correct, the problem was with Rosbridge. It works, but seems to shut down or not be started properly. However cle-rosbridge after starting cle and the frontend fixes the problem - everything in web cockpit now functioning as should!

Again, thanks a lot!


Ps. I’m using nrp compiled from source, in case it’s of use to anyone seeing this.