Switching device 1424 can be used to create Simplebus systems of up to 120,000 users. It can also be used to create multi-villa systems with doors and porter switchboards, centralising up to 500 Comelit Simplebus KITS. Furthermore, the device also makes it possible to control main and secondary switchboards within a system (which can be called independently) and offers alarm signalling to those particular switchboards. It allows cascade bus line distribution as an alternative to star distribution, optimising the connection topology for the part of the system before the mixers 4888 and 4888C. It has a self-powering function for the LS|LS input, which allows riser management without requiring a dedicated secondary external unit. Power supply 12Vac (Art. 1200 may be used) -20Vdc. Housed in a box with 4 DIN modules. Dimensions 60 x 85 x 35 mm.