A common requirement for local authorities and housing associations, apartment isolation simplifies fault finding while adding an extra layer of protection to a system. In the event of a fault within an apartment, or the wiring to an apartment the line isolation will ensure that only one apartment is affected allowing the remaining apartments on the systems to function as normal. The Vx2200 system uses optional 4-way apartment audio isolation cards and for video systems a piggyback board serves to protect the additional cables required for video, both saving space and simplifying connections. Each card includes 10 LEDs to assist an engineer should a fault occur on the system.-Channel in use, voltage fault and bus fault conditions are all signaled. To further assist the engineer all connections are plug type to allow simple swap out while testing. The cards are designed to be either distributed around the building or contained in a control cabinet in one or more locations.