The emergency assist alarm call systems within a centralized full duplex voice communication system, providing a single display point for all disabled calls within a building. When a call is made the over-door and cancel units emit a two tone siren with the “Halo” flashing, when the call is acknowledged from the EVCS controller the “Halo” on these units lights steadily and the tone double beeps every 15 seconds to reassure the caller help is on the way. As DTA system is connected to a Master Control panel the plates and cables are fully end of line monitored and battery backed as standard. DTA plates are supplied with a brushed stainless finish and a Blue HALO to aid location.