rosbridge_client

This package provides a client for the rosbridge_suite's server.

Installation

To install the package, first install the dependencies.

pip install rospy_message_converter roslibpy

Then, install the package itself.

catkin build rosbridge_client

On the remote site, the rosbridge_suite needs to be installed (e.g. ros-noetic-rosbridge-suite).

Nodes

rosbridge_transceiver

This node connects to a remote ROS instance running a rosbridge_server via a websocket. It lets the user chose a set of local and remote topics, which shall be forwarded to the remote and local site, respectively.

Parameters

• hostname is the hostname of the machine running the remote ROS instance. Default: localhost
• port is the port of the remote rosbridge_server. Default: 9090
• send is a comma-separated list of local topics to forward. An alternative remote topic names can be provided.
• recv is a comma-separated list of remote topics to receive. An alternative local topic names can be provided.

Alternative remote (local) topic names when sending (receiving) topics have to follow the local (remote) topic name delimited via a colon ':'. For example, the following argument for the send parameter would forward the local topics l1 and l2 to remote topics r1 and r2.

_send:=l1:r1,l2:r2

The next example receives the remote topic r1 and r2 and publishes the messages locally via topics l and r2.

_recv:=r1:l,r2

Example

The system can be tested on a single machine as follows.

Install the rosbridge_suite:

apt install ros-noetic-rosbridge-suite

Run the server:

roslaunch rosbridge_server rosbridge_websocket.launch port:=9090

Note, that the port parameter can be omitted. In this case, the default port 9090 will be used.

After installing the package locally, run the client node:

rosrun rosbridge_client rosbridge_transveiver _port:=9090 send:=/in:/out _recv:=/rin:/rout

Now, running two rostopic echo commands will listen to the forwarded topics.

rostopic echo /out
rostopic echo /rout

Sending two messages will yield an output on the two topics above.

rostopic pub -1 -s /in std_msgs/String "{data: 'Hello from local'}"
rostopic pub -1 -s /rin std_msgs/String "{data: 'Hello from remote'}"