sm_fan_control

State machine implementing fan control and anti-chatter behavior.

Inherited Component

Control_Manager

Inherited Requirements

Relationship Diagram

SW Unit Relations

Incoming Relations

Relation	UML Type	Visibility	Source Unit	Description
SWR-004	composition	private	ao_control	Control active object embeds fan control state machine.

Data Types

sm_fan_control_contextstruct

Internal runtime context for sm_fan_control.

Struct Members

Name	Type	Description
sm_state	uint8_t	Fan SM current state.
output_on	bool	Fan output state.
override_active	bool	Override active state.
transition_tick	uint32_t	Last state transition tick.

sm_fan_control_eventstruct

Event payload handled by sm_fan_control.

Struct Members

Name	Type	Description
signal_id	uint16_t	Fan SM event id.
request_on	bool	Requested output state.
protect_active	bool	Protection input.
feedback_ok	bool	Feedback validity.

sm_fan_control_resultenum

Result code for sm_fan_control operations.

Enum Members

Name	Value	Description
OK	0	State transition applied.
INVALID_TRANSITION	1	Illegal transition for current state.
FORCED_SAFE	2	Output forced to safe state.

Attributes

Attribute	Type	Visibility	Description
ctx	sm_fan_control_context	private	Runtime context for sm_fan_control state timing and error tracking.

Methods

dispatch

Return Type: sm_fan_control_result
Visibility: public
Description: Process one sm_fan_control event and update runtime outputs.

Parameters

Name	Type	Direction	Description
event	sm_fan_control_event	in	Process one sm_fan_control event and update runtime outputs.

init

Return Type: sm_fan_control_result
Visibility: public
Description: Initialize sm_fan_control runtime state and dependencies.

Dynamic Behaviour

State Machines

sm_fan_control_state

This state machine captures hysteresis based fan actuation with anti chatter holdoff semantics and protective override handling so temperature threshold crossings produce stable deterministic fan transitions under noisy boundary conditions.