STEP 7 - Micro/Win32, v. 3.0.2.020, CPU 221, from Siemens Energy & Automation, Inc. This PLC was taken the model to the SimuPLC by cause its good reputation at market and of the power of its Statement List - STL language, that has served the base for the instruction list IL implemented in the Simulator. And, yet, due to the fact that it was the equipment which my brother Benjamim, electrotechnician, taught me the fundamental concepts of the electro-electronic logical programmable controls.