Attention: Answers.ros.org is deprecated as of August the 11th, 2023. Please visit robotics.stackexchange.com to ask a new question. This site will remain online in read-only mode during the transition and into the foreseeable future. Selected questions and answers have been migrated, and redirects have been put in place to direct users to the corresponding questions on Robotics Stack Exchange. Additional details are available here.

Data loss between publisher and subscriber

asked 2017-10-03 17:15:12 -0600

_nobot.enter
5 ●2 ●5 ●5

Hello

I was running ROS package with one publisher and subscriber in below link. https://github.com/oroca/oroca_ros_tu...

Basically, publisher sends a number (add 1 every loop) and subscriber gets it.

So, I run subscriber first, then run publisher in a different terminal.
Then I could see that there was a loss.

Publisher starts with 0, but Subscriber gets from 3.

Is this normal? Is this solvable?

Thank you in advance.

edit retag flag offensive close merge delete

add a comment

1 Answer

Sort by » oldest newest most voted

answered 2017-10-05 04:21:17 -0600

Stefan Kohlbrecher

24361 ●173 ●299 ●444 https://www.energy-rob...

When a publisher is created, there is some setup performed "behind the scenes", such as registering with the ROS Master and potential subscribers. This means that when one publishes immediately after creation of the publisher, messages might not actually get out because the Publisher wasn't "ready" yet. See for instance also other Q/As such as this one. Pretty sure that adding a sleep here in line 13 would fix the issue.

edit flag offensive delete link

Comments

Thanks Stefan Kohlbrecher :D

_nobot.enter ( 2017-10-05 13:50:17 -0600 )edit

add a comment

Question Tools

2 followers

Stats

Asked: 2017-10-03 17:15:12 -0600

Seen: 392 times

Last updated: Oct 05 '17

Data loss between publisher and subscriber edit

1 Answer

Comments

Question Tools

Stats

Related questions

Data loss between publisher and subscriber