using "types";

FlowSheet sample_timer
    PARAMETERS
    Timer as Switcher(Valid = ["closed", "opened"], Default = "closed");
	
	TimeOpened as time_sec;
	TimeClosed as time_sec;

	VARIABLES
	Clock as Real;
	flow as flow_vol;
	
	SET
	TimeOpened = 2*'s';
	TimeClosed = 4*'s';
	
    EQUATIONS

    switch Timer
	case "closed":
		flow = 0 * 'm^3/h';
		
		diff(Clock) = 1/TimeClosed;
		when Clock > 1 switchto "opened";

	case "opened":
		flow = 1 * 'm^3/h';
		
		diff(Clock) = -1/TimeOpened;
		when Clock < 0 switchto "closed";
	end
	
	INITIAL
	Clock = 0;
	
	OPTIONS
	TimeStep = 0.1;
end