Patents Assigned to Da-Tel Research Co., Inc.
  • Private automatic business exchange
    Patent number: 5070523
    Abstract: The invention interfaces a two-wire line to many smart terminals, modems or telephones only one of which is in use at a time. The invention is used by electric utilities in substations to automatically transfer stored data originating in the substation to a central control room.
    Type: Grant
    Filed: May 22, 1989
    Date of Patent: December 3, 1991
    Assignee: Da-Tel Research Co., Inc.
    Inventors: George F. Hafer, Lanham P. Rattan