In this paper is proposed a stochastic interpreted Petri net, (st-IPN) as a model to represent the regular language derived from the combination of input signals in a Discrete Event System (DES) in closed loop. The input signals are external signals affecting the system and the control commands issued by the controller to the plant and the output signals are the responses of the sensors to the control commands. The st-IPN proposed is a deterministic generator of the system legal language able to represent sequences of stochastic timed events. The proposed model can be applied to large-scale systems, from the division of the system into subsystems, since the global model can be a composition of the subsystems models.