# Revision history [back]

### ROS2 Managed node: triggering an error

I have a managed node with a thread running during when it is in ACTIVE ' state.

During the execution an error can occur and I have not understood how to trigger an error event to enter into the on_error callback, manage the error and going back to UNCONFIGURED ' state if the error can be solved.

on_error callback is executed when a transition callback returns TRANSITION_CALLBACK_ERROR or an unhandled exception is generated... but when the node is in a Primary state?

Thank you Walter

### ROS2 Managed node: triggering an error

I have a managed node with a thread running during when it is in ACTIVE ' state.

During the execution an error can occur and I have not understood how to trigger an error event to enter into the on_error callback, manage the error and going back to UNCONFIGURED ' state if the error can be solved.

on_error callback is executed when a transition callback returns TRANSITION_CALLBACK_ERROR or an unhandled exception is generated... but when the node is in a Primary state?

Thank you Walter

### ROS2 Managed node: triggering an errorerror from primary state

I have a managed node with a thread running during when it is in ACTIVE ' state.

During the execution of the thread an error can occur and I have not understood how to trigger an error event to enter into the on_error callback, manage the error and going back to UNCONFIGURED ' state if the error can be solved.

on_error callback is executed when a transition callback returns TRANSITION_CALLBACK_ERROR or an unhandled exception is generated... but when the node is in a Primary state?

Thank you Walter