sync_params

This package synchronises parameters between multiple masters. It periodically reads from the parameter server, publishes it to a global topic, then writes to the parameter server. It’s intended to work across multiple masters in multimaster_fkie setups. Tested for versions Indigo and Kinetic.

Only new parameters will be written to the parameter server. No parameter will ever be overwritten.

By default, all parameters will be synchronised. The blacklist excludes parameters based on their name. The whitelist parameters are exempt from the blacklist. These can both be regular expressions. For example:

blacklist = ["/*"]
whitelist = [/my_parameter]

Would only synchronise my_parameter.

The parameter use_wall_time is designed for spawning robots in Gazebo. Gazebo pauses the ROS clock when loading a robot, and waits for the robot_description parameter. But that parameter might not get synchronised if sync_params uses the ROS clock.

1. Nodes

1.1 sync_params_node

1.1.1 Subscribed Topics

/params (sync_params/ParameterMsg)

The parameters to be synced.

1.1.2 Published Topics

/params (sync_params/ParameterMsg)

The parameters to be synced.

1.1.3 Parameters

~debug (boolean, default: False)

Whether to print out lots of information

~rate (double, default: 1.0)

The rate to read/publish/write parameters

~death_timer (double, default -1.0)

How many ROS seconds until publishing stops

~use_wall_time (boolean, default: False)

Whether to use computer clock instead of ROS clock. Does not affect death_timer

~blacklist (array, default: [])

List of parameter names to exclude from synchronising

~whitelist (array, default [])

List of parameter names to exclude from the blacklist