The description of the design and automation of a hard nickel electroplating pilot plant using rectangular pulse current is presented. For the automation of this process the Petri nets (PN) are described and used, starting from their more basic form and justifying why to use higher levels of abstraction or extensions of the same ones. These levels include the IPN (Interpreted PN), HPN (Hierarchical PN) and, finally, as a complement to this article the use of the HCPN (Hierarchical Colored PN). The results are reflected in the reduction of the pattern complexity due to the properties of modularization of the nets of higher level.