ViLX-ACA Lexicomm Assist Call Alarm WC SystemViLX ACA Lexicomm Assist Call Alarm WC System The ViLX ACA provides a simple solution to integrating emergency assist call systems within an EVCS, providing a single display point for all disabled calls within a building. It can be used on a dedicated line, or may share a line with the ViLX OSB disabled refuge outstation, where operation of the refuge point over rides the assistance call (ideal where a disabled toilet is adjacent to a refuge lobby)