function [bonds,status] = ES_cause(bonds);
% Causality for ES component
%SUMMARY ES: converts thermal pseudobond to true bond and vv
%DESCRIPTION Port [e]: temperature (T) / enthalpy flow (E) bond
%DESCRIPTION Port [s]: temperature (T) / entropy flow (S) bond
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% Version control history
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% $Id$
% %% $Log$
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Copyright (c) P.J. Gawthrop, 1997.
status = -1;
% Check that there are exactly two bonds.
if check_bonds(bonds,2,'ES')==0
return
end
% Same causality as TF
[bonds,status] = TF_cause(bonds);