PC-BASED CLOSED-CIRCUIT TELEVISION SYSTEM

Year
1990
Author(s)
Daniel A. Christoffersen - Sandia National Laboratories
Carl M. Clark - Sandia National Laboratories
Abstract
The PC-based closed-circuit television (CCTV) s y s t em is a low-cost, highly functional alternativ e to conventional video system equipment. The system provides routing switching, character generation, video presence detection, and solid-state video recording and replay by using four uniquely designed boards that fit into the backplane slots of an IBM PC-XT-compatible personal computer. Each board controls 16 separate channels, and the boards can be daisychained together to build larger, more powerful systems. The system can be configured to handle as many as 240 input signals or up to 48 output channels, and uses a redundant video bus loop. The video bus can be tapped into throughout the loop to provide (1) localized routing switching within several buildings, and (2) video termination at multiple locations, such as security operators' stations. This approach reduces cabling costs and allows additional routing switchers to be added easily with little impact on existing equipment. The system is capable of communicating with several control interfaces, and control software is currently in place for communicating via an RS-232 link and the Intel BitBus network. The hardware drivers are Microsoft C modules that can be linked with a user-developed control program.