Nowadays it is possible to successfully adopt a virtual/constructive approach in the contest of automated manufacturing systems. The design and the implementation of the control software is usually not considered a crucial step in the development cycle of these systems but it plays a key role to reduce time and costs of the real commissioning. Recent computer technology progress, some results from discrete event systems research and the MATLAB toolbox SUP2PLC (here available) can be exploited to effectively speed-up the design/implementation of control software in the context of virtual/constructive commissioning.