search

fkie / multimaster_fkie

ROS stack with FKIE packages for multi-robot (discovering, synchronizing and management GUI)
BSD 3-Clause "New" or "Revised" License
268 stars 108 forks source link

node manager warning #34

Closed Georacer closed 8 years ago

Georacer commented 8 years ago

Hello,

I am trying to connect two roscores, one running on an Ubuntu laptop and another running on an Ubuntu Odroid XU3, both with ROS Indigo.

I have successfully followed all the steps for the single network configuration from here: http://www.iri.upc.edu/files/scidoc/1607-Multi-master-ROS-systems.pdf

I am able to publish a topic from the laptop and read it on the Odroid.

However, when I try to open the node_manager to get a better idea of my network, I get the following warning, regarding the quality of the link and the time slip.

screenshot from 2016-03-30 23 17 58

Is there something I need to worry about or something I can do about it?

Thanks

atiderko commented 8 years ago

Hello @Georacer,

the warning about time slip is particularly interesting when tf is synchronized. You can remove the warning by:

  1. Increasing the Max time difference value in Settings-Tab (Default: 0.5 sec)
  2. Sync the clock of both hosts
  3. Set the current time of localhost to odroid-time using the button beside username-combobox in the yellow control panel.

regards, atiderko

Georacer commented 8 years ago

Hello @atiderko

Thank you for your swift reply. Alas, my follow-up was not so swift.

On 1): I can find the code for said settings tab (https://github.com/fkie/multimaster_fkie/blob/f3af64bd1b733e64615b5960316975e9cb8567f4/node_manager_fkie/src/node_manager_fkie/settings_widget.py) but for the love of me I cannot find how to open this tab from node_manager. A screenshot with the location of the button would be helpful. I take it you are not referring to the heartbeat rate.

On 2): Do you mean that I should eg connect both PCs to the internet and let them auto-adjust their clocks, or something more involved?

On 3): If I start node_manager on the laptop, I can only command a time-set (to laptop-time) on the Odroid. That is initially rejected due to lack of su rights, but the error message explain what to do about that.

Additionally, the same configuration today seems to work without errors (no weird colours!) Perhaps I was having an intermittent problem.

Other than that, could you tell me the meaning of the icon and its colour, which is on the top left, between the sync toggle button and the hostname and looks like a plug? screenshot from 2016-04-05 23 21 41

Thanks.

P.S. If you think we're done here, you can go ahead and close this ticket.

atiderko commented 8 years ago

Hello @Georacer,

1) I see your settings-tab is not displayed. Normally it is displayed beside on tabs with launchfiles and description: node_manager_settings Did you have error outputs in the console where node_manager was started? Try to delete $HOME/.ros/node_manager/settings.ini, perhaps it helps.

2) Yes, or you setup your own NTP-server ;-)

3) It was a designe decision: time change option is a temporary fix, so you have to change only the localhost.

I let this ticket open until we find the settings tab ;-)

regards

Georacer commented 8 years ago

Yup! That did it. I can see it now, thanks!

The multimaster stack seems really useful for what I want to do. Are there other documentation resources apart from http://fkie.github.io/multimaster_fkie/ and http://www.iri.upc.edu/files/scidoc/1607-Multi-master-ROS-systems.pdf ?

atiderko commented 8 years ago

there are also a chapter in http://www.springer.com/us/book/9783319260525