Hi Eitan -
I'm inclined to say that this isn't a network issue since lots of other 
things work, like streaming video from the robot using image_transport 
(and iwconfig shows really good link quality), but I'll try your 
suggestions next time I'm in the lab.

Thanks,
-Dan

On 4/16/10 4:12 PM, Eitan Marder-Eppstein wrote:
> Dan,
>
> Those are strange problems to have. A hunch I have is that nav_view 
> has dropped its TCP connection to the robot for one reason or another 
> on certain topics. This happens to us sometimes when we're switching 
> between being connected to our robots over ethernet to wireless or 
> when we lose connectivity to the robot for long periods of time. I'd 
> be curious about a few things:
>
> 1) Can you get things to start displaying in nav_view by running the 
> following command:
>      rosrun topic_tools relay [missing_topic_name] [missing_topic_name]
>     This will re-advertise the topic and cause nav_view to refresh its 
> TCP connections.
>
> 2) Are you sure that the robot can connect to the machine that's 
> running nav_view? Have you been running rostopic echo on the robot 
> itself? Or on the local machine?
>
> 3) If you use rviz, do you see the same kind of problems. If this is a 
> network issue, I'd expect you to see the same problems, but it'd be 
> useful to know.
>
> Hopefully this helps or we at least find out more about what's going on.
>
> Hope all is well,
>
> Eitan
>
> On Fri, Apr 16, 2010 at 1:54 PM, Dan Lazewatsky 
> <lazewatskyd@cse.wustl.edu <mailto:lazewatskyd@cse.wustl.edu>> wrote:
>
>     Hi all -
>     We've been trying to get the nav stack running on one of our
>     robots and
>     are having some frustrating and not totally reproducible problems. Nav
>     is setup from config files that I got working on an erratic and have
>     modified for this robot. When I start up nav_view after getting amcl,
>     move_base and the like going, most of the time I don't see any laser
>     scan, inflated obstacles etc. in nav_view and using Set Pose
>     doesn't do
>     anything. move_base/local_costmap/obstacles is publishing data, and
>     rxgraph shows it connected to nav_view. When I use Set Pose, I can see
>     the message getting sent off, but the new pose is not reflected in
>     nav_view. Sometimes, I'll see the inflated obstacles in nav_view, but
>     once the map shows up they disappear.
>
>     Any help would be much appreciated,
>     -Dan
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