Abstract: A railroad vital signal output module provides a predetermined output signal in response to a certain module input only under conditions that insure vitality of the output signal. The module includes a master microcontroller and a plurality of slave microcontrollers. The master microcontroller generates a periodic clock signal and a plurality of pseudo-random numbers in a predetermined sequence. Each slave microcontroller generates a plurality of pseudo-random numbers in the same predetermined sequence as the master microcontroller. The numbers from the master microcontroller are compared with the numbers in the slave microcontroller if the clock signal is received at a slave master controller in a predetermined window of time and if there is identity between said pseudo-random numbers, the module provides a predetermined output signal which is assured to be vital.