The article shows how to incorporate the 'ideal' video switcher in closed-circuit television (CCTV) installations, which will meet the requirements of contemporary Advanced Traffic Management Systems (ATMS) applications. A video switcher is the heart of a CCTV system. Where noise is a major consideration, as for traffic surveillance applications, the right product should be selected very carefully. The following checklist is provided: (1) full matrix switching fully looped; (2) vertical interval switching; (3) 70dB S/N (weighted); (4) 60dB cross talk at 3.58MHz; (5) differential phase shift less than 1 degree; (6) differential gain less than 1%; (7) bandwidth +/- dB greater than 10MHz; (8) full support titling with borders; (9) video loss detection; (10) redundant power supply; (11) cage configuration with slide in printed-circuit boards; (12) rack-mounted high-density cages; (13) coaxial ribbon cable interface; and (14) built-in diagnostics. If a switcher is selected, that satisfies all these criteria, it will not be necessary to design specific equipment for the application.
Abstract