Abstract: Microprocessor based safety system applicable, in particular, to the field of rail transport, for monitoring and controlling actuators (ACT) as a function of the data supplied by sensors (CP), characterized in that it includes at least two microprocessors (P1, P2) in parallel handling the same application, the inputs of which receive the pre-encoded data (DE) from the sensors (CP), and the output data of which is read back in safety for comparison with the input data, and a third, comparison microprocessor (P3) known as a voter, for comparing, using software and in safety, the encoded characteristic results (R1, R2) of the two application microprocessors (P1, P2) and operating in consequence a dynamic controller (CD) authorizing the transmission of the output data (DS) to the actuators (ACT).