State Machine Glossary

ActionLoop Worker-loop abstraction that processes queued actions sequentially in a dedicated thread. Used to decouple device logic from EPICS callbacks and UI threads.

Acquire State reported by EPICS indicating whether the device is currently acquiring data.

Acquire Started Internal state variable indicating a request to begin acquisition before EPICS confirms the acquire state.

Action Unit of work queued to the worker loop using action(name, arg) which dispatches to action_<name> methods.

Event External input or device change that may trigger a state transition in the state machine.

Finite State Machine (FSM) Programming model that represents system behavior as states and transitions between them.

Mealy Machine State machine where outputs depend on both the current state and the triggering event.

Moore Machine State machine where outputs depend only on the current state.

State Representation of the current condition of a system, typically stored in a variable or structure.

State Transition Change from one state to another triggered by an event or condition.

State Transition Table Table defining which transitions between states are valid.

State Machine Software structure that encapsulates state variables and transition logic.

Worker Thread Dedicated thread that processes queued actions and device operations sequentially.

Worker Queue Queue of actions waiting to be processed by the worker thread.