Question 1

How do I switch DDS implementations in ROS 2 using rmw?

Accepted Answer

You can select rmw implementations at runtime or build time by setting environment variables like RMW_IMPLEMENTATION, but this requires understanding each implementation's configuration and potential compatibility issues.

Question 2

What are the key differences between rmw_fastrtps and rmw_connext?

Accepted Answer

rmw_fastrtps is open-source and commonly used for its flexibility, while rmw_connext is commercial and offers advanced features like deterministic performance, but licensing and cost differ.

Question 3

Can I use a custom DDS with rmw in ROS 2?

Accepted Answer

Yes, you can implement a custom rmw plugin by adhering to the abstraction layer API, but it requires significant development effort and testing to ensure compatibility with ROS 2.

Question 4

How does rmw handle interoperability with different DDS versions?

Accepted Answer

The rmw interface standardizes communication, but underlying DDS version mismatches might cause issues, so it's crucial to use compatible implementations and check vendor documentation.

Question 5

Is rmw suitable for real-time robotic applications?

Accepted Answer

It allows performance tuning by choosing DDS implementations optimized for real-time, but the abstraction layer adds overhead, so direct DDS usage might be better for ultra-low latency needs.

Question 6

What happens if I mix rmw implementations in a ROS 2 network?

Accepted Answer

The interoperability feature ensures basic communication, but advanced features or QoS settings might not translate perfectly, potentially leading to dropped messages or degraded performance.

rmw

Overview

Use Cases

Not Ideal For

Pros & Cons

Pros

Related Projects

Found a gem we're missing?

Cons

Frequently Asked Questions