Controlled Access Line Integrity
Original Publication Date: 1978-Jun-01
Included in the Prior Art Database: 2005-Feb-21
A digital test is provided to determine existence of an "open door" or "open line" in a controlled access system. Such a system may use a magnetic stripe card or badge reader at each door to control access into a building or other secured area. In a typical system, the reader requires a four wire hook-up system.