An electronic unit for monitoring and controlling one or more fire sensors arranged in loops of a fire detection system, comprising: - a processing stage; - a managing stage of said one or more sensors which can be connected to said one or more sensors, said managing stage being activated by the processing stage to generate digital cyclical querying signals (S1, S2) to be sent to said one or more sensors to verify their operative state; - an electrical power supplying stage configured to generate direct current electrical potentials to be supplied to the managing stage of the sensors starting from a predetermined reference power supply potential (Vcc) referred to a ground potential, characterized in that said electrical power supplying stage comprises a first electronic circuit (30, 40, 50) to generate: - a first potential higher than the reference potential (Vcc) to be supplied to the managing stage of the sensors; - a second potential equal to the reference potential (Vcc) to be supplied to the managing stage of the sensors; - a third potential lower than said reference potential (Vcc) to be supplied to the managing stage of the sensors, and said managing stage of the sensors comprises a second electronic circuit (60, 61, 65, 66) to generate: - a first digital cyclical querying signal adapted to assume a high level equal to the second potential and a low level equal to the third potential, - a second digital cyclical querying signal adapted to assume a high level equal to the first potential and a low level equal to the second potential, said first and second digital cyclical querying signals being associated with different communication protocols to be made available to the fire sensors of different type of the fire detection system. - a processing stage; - a managing stage of said one or more sensors which can be connected to said one or more sensors, said managing stage being activated by the processing stage to generate digital cyclical querying signals (S1, S2) to be sent to said one or more sensors to verify their operative state; - an electrical power supplying stage configured to generate direct current electrical potentials to be supplied to the managing stage of the sensors starting from a predetermined reference power supply potential (Vcc) referred to a ground potential, characterized in that said electrical power supplying stage comprises a first electronic circuit (30, 40, 50) to generate: - a first potential higher than the reference potential (Vcc) to be supplied to the managing stage of the sensors; - a second potential equal to the reference potential (Vcc) to be supplied to the managing stage of the sensors; - a third potential lower than said reference potential (Vcc) to be supplied to the managing stage of the sensors, and said managing stage of the sensors comprises a second electronic circuit (60, 61, 65, 66) to generate: - a first digital cyclical querying signal adapted to assume a high level equal to the second potential and a low level equal to the third potential, - a second digital cyclical querying signal adapted to assume a high level equal to the first potential and a low level equal to the second potential, said first and second digital cyclical querying signals being associated with different communication protocols to be made available to the fire sensors of different type of the fire detection system. - a first potential higher than the reference potential (Vcc) to be supplied to the managing stage of the sensors; - a second potential equal to the reference potential (Vcc) to be supplied to the managing stage of the sensors; - a third potential lower than said reference potential (Vcc) to be supplied to the managing stage of the sensors, and - a first digital cyclical querying signal adapted to assume a high level equal to the second potential and a low level equal to the third potential, - a second digital cyclical querying signal adapted to assume a high level equal to the first potential and a low level equal to the second potential, said first and second digital cyclical querying signals being associated with different communication protocols to be made available to the fire sensors of different type of the fire detection system.