Thanks Paul,
If i understand, the right thing to do is a loop with event-struct which enqueue state modification in a queue and a parallel loop for state machine.
The parallel loop check at each loop if a new state changement is in the queue before conditionnal struct if no data in the queue state machine execute next state . But if state machine change UI Display it must me done in the state machine loop or in the loop-event struct with user-event to transmit data ?