State Machine Model of Run Control

Each component is a collection of software and possibly hardware which at any point in time is in one of several possible states. The state transition diagram shown in 3.1 describes the behavior of a single component, and of the system as a whole.

Each command (Configure, Download, Prestart, Go, Pause, End, Terminate) is automatically propagated from the system down to each component in a user definable priority order. If any component fails to successfully make the state transition, the system as a whole remains in the previous state. Many transitions are performed asychronously through intermediate states not shown in the figure.