[ros-users] [Discourse.ros.org] [Next Generation ROS/Troubleshooting] ROS2 talker listener using difffernt DDS

[dhood]

You can set the `RCL_ASSERT_RMW_ID_MATCHES` environment variable to be sure. If it doesn't match you'll get an error like:

```
$ RCL_ASSERT_RMW_ID_MATCHES=rmw_connext_cpp RMW_IMPLEMENTATION=rmw_fastrtps_cpp ros2 run demo_nodes_cpp talker
Expected RMW implementation identifier of 'rmw_connext_cpp' but instead found 'rmw_fastrtps_cpp', exiting with 102.
```

We have ideas for how to make this introspection easier for users in the future, but for the meantime I've added this info to the wiki page.





---
[Visit Topic](https://discourse.ros.org/t/ros2-talker-listener-using-difffernt-dds/2124/4) or reply to this email to respond.