proxy_tools: proxy
Package Summary
Proxy provides a repeater node. Using the proxy, several clients can subscribe to a topic on the other side of a slow network connection using no more bandwidth than what's needed for a single subscriber. This node can relay multiple topics, and it only subscribes to the topics to which its downstream nodes are listening.
- Author: Ken Tossell
- License: BSD
- Repository: umd-ros-pkg
- Source: git http://ram.umd.edu/git/ros/proxy_tools.git
Contents
proxy is a multi-topic, on-demand repeater for message streams.
Usage
Start the proxy with your desired prefix:
$ rosrun proxy proxy _prefix:=/proxy
Subscribe to a repeated topic (suppose you have a topic /scan):
$ rostopic echo /proxy/scan
Notes
If you do not need support for multiple topics or on-demand subscription, you could use the relay node from topic_tools.
proxy will only relay topics whose messages are defined on the system where proxy runs. This limitation exists because publishers are required to advertise some information that is not available through the rosmaster API, such as the message hash and message definition.
If you run multiple proxy instances, the proxies will repeat each other's topics, but they will not create a loop. You can use this to create message chains like the following:
/proxy3/proxy2/proxy1/scan
When you first subscribe to that topic, proxy 3 will subscribe to proxy 2, which will subscribe to proxy 1, which will read in the original message.