Abstract: A system monitor sensors which control actuating elements in a building. The supervision unit essentially collects information from the sensors and controls the actuating elements. A precable system in the building connects the supervision unit to input/output connections of a plurality of interconnection devices. The plurality of interconnection devices each include a plurality of terminal boards connected to the sensors and actuating elements through a first set of cables. A microprocessor has a portion of the I/O connections connected to the terminal board through a second set of cables, transmitting signals between the actuating elements, sensors and the supervision unit.