Hi @vdiluoffo, I tried your code on my machine and the callback is called every time a message is received. Could you give more detail about your configuration? (version of the code, rmw_implementation used). How are you publishing your images? Note: I tested it running `cam2image -b` in a terminal and your code sample in another one. Cheers, Mikael --- [Visit Topic](https://discourse.ros.org/t/subscription-topic-not-connecting-to-sensor-output-data/1245/2) or reply to this email to respond. If you do not want to receive messages from ros-users please use the unsubscribe link below. If you use the one above, you will stop all of ros-users from receiving updates. ______________________________________________________________________________ ros-users mailing list ros-users@lists.ros.org http://lists.ros.org/mailman/listinfo/ros-users Unsubscribe: