sync_topics parameter not working?

[ZdenekM]

It looks like sync_topics is ignored (at least in my case). With following setup:

ROS1 (ROS_MASTER_URI=http://localhost:11312)

• rostopic pub /test/topic std_msgs/String 'Hello World' -r 1
• rostopic pub /test/topic_secret std_msgs/String 'Hello World!' -r 1
• rosrun master_discovery_fkie master_discovery
• rosrun master_sync_fkie master_sync _sync_topics:=["/test/topic"] _sync_topics_on_demand:=false

ROS2 (ROS_MASTER_URI=http://localhost:11311)

• rosrun master_discovery_fkie master_discovery
• rosrun master_sync_fkie master_sync _sync_topics_on_demand:=false
• rostopic echo /test/topic -> works (as expected)
• rostopic echo /test/topic_secret -> also works

Am I missing something or is it a bug? I would like to "flip" only selected topics between ROS1 and ROS2. Thanks in advance.

Ubuntu 14.04, ROS Indigo, multimaster_fkie from debs (also tried with current version from git).

[atiderko]

Hi ZdenekM,

you have to run rosrun master_sync_fkie master_sync _sync_topics:=["/test/topic"] on ROS2, too. In your case you don't need to start master_sync on ROS1.

The parameter of master_sync specify which remote topics, services or nodes are registered/filtered by own ROS Master. It does not matter if the master_sync is running on another host.

regards, atiderko

[ZdenekM]

Now it works fine. Thanks. This could be probably mentioned on wiki. Btw, is it possible to "remap" topic - I mean to have 'topic1' on ROS1 as 'topic2' to ROS2?

[atiderko]

I am pleased :-).

No, it is no possible to to rename topics while synchronization, because master_sync does not so deeply change ROS. There no new connections are created. master_sync registers only a new topic, the connections is done by ROS Master itself.