  Let O_{Lambda} be a higher rank graph C*-algebra of rank r. For every tuple p
of non-negative integers there is a canonical completely positive map Phi^p on
O_{Lambda} and a subshift T^p on the path space X of the graph. We show that
ht(Phi^p)=h(T^p), where ht is Voiculescu's approximation entropy and h the
classical topological entropy. For a higher rank Cuntz-Krieger algebra O_M we
obtain ht(Phi^p)= log r(M_1^{p_1}M_2^{p_2} ... M_r^{p_r}), r being the spectral
radius. This generalises Boca and Goldstein's result for Cuntz-Krieger
algebras.
