Robotics StackExchange | Archived questions

Viewing a published LaserScan from Machine A on Machine B using RVIZ

So i have Machine A and Machine B they are connected and Machine B has the same master as Machine A.

I have a base_scan topic that if is do the command

rostopic list

I will get all the correct topics no matter if i run on Machine A or B.

But when i run

rostopic echo /base_scan

It only works on the Master Machine A, and not Machine B. It just crashes eventually.

What i'm trying to do is get basescan to appear on RVIZ in Machine B but it just doesn't show no errors come up and i know basescan does appear correctly if RVIZ and base_scan are on the same machine so the only thing i can think of is there being some problem with listening to a publisher from another machine.

The machines are set up following the ROS Multiple Machines Tutorial and it works fine

I'm wondering if anyone has anything that i could try to fix this problem. Thanks in advance.

Asked by Dalecn on 2021-12-10 19:00:21 UTC

Comments

That sounds like you have not done the full network setup. Listing the topics does not require bidirectional communication. Subscribing does. If you'd like some help please edit your question to include all the outputs of the links from the bottom of the article NetworkSetup and Troubleshooting

Asked by tfoote on 2021-12-10 19:20:42 UTC

If the Multiple Machine Tutorial works properly i would of thought the Network was setup correctly as it does Publishing and Subscribing in it.

Asked by Dalecn on 2021-12-10 21:01:47 UTC

Some of the configurations are not persistent if you opened and closed a new shell you may have not set up your system again exactly right the second time. Or some of your network settings changed, or your hostnames etc. We can't help you unless you provide the debugging data to show what your actual error is. The most likely issue you are facing is that your settings don't cover your setup correctly. To help you we'll need to understand exactly what your setup is and how you have configured it. The exact steps and environment as well as the actual console outputs are what will let us help you resolve your connectivity issue.

Asked by tfoote on 2021-12-10 21:08:53 UTC

@Dalecn "it crashes eventually" is very unusual. Please confirm to us that you are running the same version of ROS on both machines.

  • The most common reason for this symptom is that a firewall is still enabled on one of the machines. Make sure you reboot the machine after disabling the firewall.
  • The next most common reason is that Machine A can not determine the IP address of Machine B.

Asked by Mike Scheutzow on 2021-12-11 09:34:10 UTC

Answers