Abstract: A frame assembly for mounting an electric wiring device to a building panel comprises an exposing frame having a front plate to be disposed on a front face of the panel, and rearwardly extending side plates projecting through an aperture in the panel. The side plates carry projections arranged to underlie an edge of the aperture to retain the exposing frame to the panel. A supporting frame is provided for holding at least one of a plurality of modularized wiring devices. The supporting frame is disposed to the rear of the panel when the supporting frame is coupled to the exposing frame. The supporting frame includes tongues arranged to be positioned to the inside of the projections of the exposing frame to elastically support the projections from being uncoupled from the panel. The modular-dimensioned wiring devices are thereby allowed to be mounted to the panel easily without screws or the like.

Abstract: A remote supervisory and controlling system in which a central control unit generates a dummy transmission signal until receipt of an interruption signal from one of a plurality of input terminal units. In response to the interruption signal, the control limit accesses the input terminal generating the interruption signal, which returns its input data.