ros2 node list empty

asked 2022-01-18 06:28:30 -0500

pablo.arandarod gravatar image

updated 2022-01-31 08:40:14 -0500

lucasw gravatar image

When trying to echo what certain topics are publishing I was executing ros2 topic echo <name-of-the-topic> and it wasn't able to echo nothing at all. I used rqt-graph to see if the topics and nodes appeared there and they do, so I used both commands ros2 topic list and ros2 node list to see if they appeared there, and they don't.

To be accurate, when using ros2 node list the list appears empty and when using ros2 topic list 2 values appear: \parameter_events and \rosout.

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You'll need to provide more detail here. Is this a multi-machine setup? Is there some node you're running that should be providing data?

cst0 gravatar image cst0  ( 2022-01-18 11:35:17 -0500 )edit

If ros2 topic list is showing only \parameter_events and rosout only, then I am afraid there are no nodes running

aarsh_t gravatar image aarsh_t  ( 2022-01-18 12:03:08 -0500 )edit

@cst0 It is all in the same machine, I'm just running a simulation in Gazebo where I'm spawning a robot and gazebo publish some info of various sensors.

Regarding @aarsh_t, when I use rqt-graph nodes and topics related to the simulation do appear.

pablo.arandarod gravatar image pablo.arandarod  ( 2022-01-18 14:20:29 -0500 )edit

Can you upload the screenshot of both in parallel?

aarsh_t gravatar image aarsh_t  ( 2022-01-19 00:26:03 -0500 )edit

Can you pls show the output of ros2 topic info <name-of-the-topic> and ros2 topic info <name-of-the-topic> -v

osilva gravatar image osilva  ( 2022-01-19 13:12:07 -0500 )edit

Also added you points so you can display the rqt-graph requested by @aarsh_t.

osilva gravatar image osilva  ( 2022-01-19 13:14:36 -0500 )edit

@osilva@aarsh_t basically I decided to delete my current installation (actually, not that much of an installation, but a build) and decided to install through apt and it is working fine for now

pablo.arandarod gravatar image pablo.arandarod  ( 2022-01-20 07:13:06 -0500 )edit

Thank you @pablo.arandarod for the update.

osilva gravatar image osilva  ( 2022-01-20 07:17:57 -0500 )edit