  In a previous paper a straight forward construction method for quantum error
correcting codes, based on graphs, has been presented. These graph codes are
directly related to cluster states which have been introduced by Briegel and
Raussendorf. We show that the preparation of a cluster state as well as the
coding operation for a graph code, can be implemented by a logical network.
Concerning the qubit case each vertex corresponds to an Hadamard gate and each
edge corresponds to a controlled not gate.
