#*-------------------------------------------------------------------
* EMSO Model Library (EML) Copyright (C) 2004 - 2007 ALSOC.
*
* This LIBRARY is free software; you can distribute it and/or modify
* it under the therms of the ALSOC FREE LICENSE as available at
* http://www.enq.ufrgs.br/alsoc.
*
* EMSO is distributed under the terms of the ALSOC LICENSE as
* available at http://www.enq.ufrgs.br/alsoc.
*-----------------------------------------------------------------------
* Author: Jonathan Ospino P.
* $Id: Lead_Lag.mso  2012$
*---------------------------------------------------------------------*#

using "types";
 
Model Lead_Lag
	
	ATTRIBUTES
	Pallete=true;
	Icon="icon/Lead-Lag";
	Info="== Lead-Lag Unit ==
	      
		  It takes an input variable and computes 
	      the respective value of the output variable according
	      to a Lead-Lag Unit Dynamics.";
	
	PARAMETERS
	TauLD as time_sec(Brief="Lead Time constant");
	TauLG as time_sec(Brief="Lag Time constant");
			
	VARIABLES
	in In as Real(Brief="Input variable",Protected=true,PosX=0,PosY=0.5);
	x as Real(Brief="Intermediate variable",Hidden=true);
	out Out as Real(Brief="Output variable",Protected=true,PosX=1,PosY=0.5);
	
	EQUATIONS
	
	#* A lead-lag unit can be interpreted as a pure lag unit
	followed by a pure lead unit
	*#
	
	"Pure Lag Unit Dynamics (FOD)"
	TauLG*diff(x)+x=In;

	"Pure Lead Unit Dynamics (FOD)"
	Out=TauLD*diff(x)+x;

	INITIAL
	x=0;
end