#*-------------------------------------------------------------------
* 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 Copyright (C) 2004 - 2007 ALSOC, original code
* from http://www.rps.eng.br Copyright (C) 2002-2004.
* All rights reserved.
*
* EMSO is distributed under the therms of the ALSOC LICENSE as
* available at http://www.enq.ufrgs.br/alsoc.
*-----------------------------------------------------------------------
* Author: Tiago Osório
* $Id: lead_lag.mso 354 2007-08-30 17:17:16Z arge $
*---------------------------------------------------------------------*#

using "types";
 
 
Model Lead_lag

ATTRIBUTES
	Pallete 	= true;
	Icon 		= "icon/Lead_Lag"; 
	Brief 		= "Model Lead lag.";
	Info 		=
"== Inputs ==
* One input signal.
	
== Outputs ==
* One output signal.
";
	
	PARAMETERS
    gain  as positive (Brief="model gain");
	beta  as positive (Brief="lead time constant", Unit='s');
	alpha as positive (Brief="lag time constant", Unit='s');
	
	VARIABLES
	input  as Real (Brief="input signal");
	output as Real (Brief="output signal");
	aux    as Real (Brief="internal variable");
	
	EQUATIONS
	
	"Calculate variable aux"
	alpha*diff(aux)=gain*input-aux;
	
	"Calculate output"
	output=beta*diff(aux) + aux;

	INITIAL
	diff(aux)= 0/'s';
	
end