When learning different control related concepts and methods, simulation is often used as a training tool; but, it does not have some real time characteristics of implementation like dealing with coding and PC resources, supervision, and communications. In some cases, implementation cannot be carried away, since it involves hardware design and is expensive. The proposed solution in this paper involves low-cost Hardware-in-the-Loop for the Real Time Simulation of the plant or process to be controlled, a PC acting as a controller and a supervisor, and communications via Ethernet between the elements. It has the following advantages: new processes can be controlled by the PC without having to change the topology of the system; modifications on the plant or controller only require software changes; and has the potential of being extensible to a real system if the simulator software is changed to work as an Ethernet to analog decoder/transducer.