(* === DECLARATION === *)
TYPE struct_boiler_status :
STRUCT
    // State
    state: BOOL;              // Current boiler state (ON/OFF)
    relay_output: BOOL;       // Actual relay output state
    
    // Runtime Info
    on_time_minutes: INT;     // Current ON time in minutes
    remaining_minutes: INT;   // Remaining time before auto-shutoff
    
    // Safety Status
    emergency_active: BOOL;   // Emergency stop is active
    time_limit_reached: BOOL; // Max time limit was reached
    
    // Error Handling
    error_state: BOOL;        // Error detected
    error_code: INT;          // Error code (0=none, 1=emergency, 2=time limit)
END_STRUCT
END_TYPE

(* === IMPLEMENTATION === *)