Catalog > Consumer Electronics > Security & Alarms > Access Control > Video Doorphones Centre Switch Centre Switch VDAS-CENTRE SWITCH VDAS CENTRE SWITCH . Discontinued Specifications, Prices & Availability may change without notice. Images are for illustration purposes only. E&OE Overview 4 Ports of the switch are connected to building Bus (outdoor stations or VAP), the other four ports are connected to management center or Wall station. It reaches the function of channel switch.