Required to install a VDS guard unit on an installation with outdoor panels. In the case of a video installation, use a coaxial cable. This module must not be used without this type of cable. This module allows active devices to be selected and establishes the communication between them: - Guard Unit<-->Apartment terminals. - Guard Unit <-->Panel. - Panels <-->Apartment terminals. For installations without outdoor panels, the installation of the guard unit does not require a connection module.