CCTV

Jun 1, 1999 12:00 PM, Access Control & Security Systems Integration Staff

Range of 24v AC camerasEasy to installThe line lock feature allows several cameras to connect to one low-cost video switcher. By eliminating ground-loop problems that complicate large camera installations, the 24v AC range facilitates installation at a lower cost.Features: can be powered from an existing 24 VAC source using an inexpensive 120v to 24v AC transformer; electrical isolation.V25, V27, V60 rangesSilent WitnessSurrey, B.C., CanadaVideo storage systemStores data digitally

The system captures images at a better resolution than a VCR and stores the data in a digital format, according to the manufacturer. On-site and remote access to live or stored information is possible from a desktop PC.Features: captures activity from all cameras simultaneously; graphical user interface; supports multitasking; multi-user system; password protected; automated, built-in disaster recovery feature; captures and displays video at 25 frames per second -live or recorded; provides up to 625 hours of hard disk storage. QStor Video Storage SystemJavelin Systems/AdemcoSyosset, N.Y.Varifocal lensesZoom lens tracking Four new lenses offer zoom lens tracking. They include: the L639VCS manual zoom with 6.5-39mm F1.4, manual focus and iris; the L851VCS manual zoom with 8.5-51mm F1.6, manual focus and iris; companion models L639VDC4P and L851VDC4P with DC-type auto irises and standard four-pin connectors.Features: each lens has glass optics; L851 offers long focal length with a 51mm maximum telephoto range, and is compatible with 1/2", 1/3" and 1/4" format CCD cameras; L639 lenses compatible with both 1/3" or 1/4" formats; lock screws prevent settings from being accidentally changed; slip clutch mounts allow additional 350 degrees of rotation after lenses are at full-thread so installers can set lock screws and knobs in various positions; auto-iris versions pre-wired with standard four-pin connectors.L639VCS, L851VCS, L639VDC4P, L851VDC4PISO Rainbow Irvine, Calif.Time-lapse recorder High-resolution images The high-density video recorder is equipped with a range of recording modes.

Features: resolution of 350 horizontal lines in black-and-white and more than 300 in color; ergonomic "Quad Mode Shuttle" dial for fingertip access to the range of transport and viewing functions; versatility is achieved through the recorder's eight standard time-lapse modes; five high-density, time-lapse modes.KV-9168AToshibaIrvine, Calif.Color quad splitter Real-time image processingThe splitter accepts four camera inputs, processes them digitally and displays them on a monitor screen. Operating and programming functions are performed with the front panel keys.Features: 2x digital zoom in VCR playback; resolution of more than 700 TV lines in single screen mode; manually selected full-screen display of cameras; sequencing program that displays each camera full screen; each camera ca- have a title of up to eight characters.V4300QSViconHauppauge, N.Y.RS-485 multiplexerProtocol independent

An eight-port multiplexer takes an RS-485 or RS-232 channel and creates eight two-wire RS-485 communication channels.Features: supports baud rates up to 38.4K, uses bus-arbitration logic on a first-come, first-served basis; detects and deactivates broken channels to protect integrity of communications bus; status LEDs for each port.MUX-8Mercury Security Corp.Signal Hill, Calif.Pan/tilt/zoom balunMade for up-the-coax panThe product eliminates coaxial cable between the pan/tilt/zoom transmitter and receiver for up-the-coax pan/tilt/zoom systems, allowing one UTP pair to be used to carry video, pan, tilt and zoom controls. Used in pairs, the balun allows CCTV security and surveillance equipment to be integrated into structured cabling systems for neater and more centralized cabling. The balun also allows pan/tilt/zoom devices to be connected to any modular wall outlet.Features: supports connections up to 2,200 or 2,500 feet via Cat 5 UTP with color or black-and-white video respectively; interfaces with CCTV pan/tilt/zoom equipment.VideoEase PTZ BalunNHC Communications Inc.Mount Royal, Quebec, Canada Video transmission Multiple network interfacesA standards-based video compression algorithm allows delivery of quality video to workstations across an enterprise network for security and remote operations management, while making efficient use of existing network bandwidth. The product captures video, compresses and transmits it over a network to a ViaNet Video Management System, which delivers the video to network workstations. Features: multiple network interfaces allow it to operate seamlessly over any LAN or WAN communications link, with minimal additional network investment; transmission of full-motion video at 30 frames per second at QCIF resolution (176x144) using only 128 kbps of network bandwidth and near full-motion video at CIF resolution (352x288) using 256 kbps; built-in digital signal processor and microcontroller; accommodates advances in video compression.VTU 2000TelexisOttawa, Ontario, Canada Video surveillance system

Internet connectivityThe system was designed for applications ranging from franchise and small businesses to law enforcement and military reconnaissance, providing real-time remote video from anywhere in the world. Configured as a stand-alone device that can operate over analog or ISDN phone lines, it connects with a PC or TV for remote viewing.

Features: Internet/IP connectivity; integrates with existing alarm and CCTV systems and remote central station applications; accommodates up to seven video and audio sources, selectable and viewable by one phone call; built-in pan/tilt/zoom capabilities; high reliability in range of industrial settings; infrared remote control and on-screen menus offer simple operation; controlled locally or remotely by other hardware through serial port.SentinelC-Phone Wilmington, N.C.

Receiver hubs Transmit video

The two devices, one passive and one active, allow full real-time monochrome or color CCTV video to be transmitted up to one mile over standard telephone wire when used with the corresponding NVT UTP/CCTV transmitter.Features: active receiver has front panel adjustable high- and low-frequency equalization and LEDs, which indicate power and video signal status for each port; both receivers are designed for mid-range and larger CCTV installations where port density and camera number growth are prevalent.NV-1613A (Passive) and NV-1662R (Active)Network Video Technologies Inc. Redwood City, Calif.Digital hybrid recorder Requires less maintenanceThe recorder uses a high-capacity hard-disk drive as a buffer and a digital videotape drive for onboard storage. The hybrid nature reduces the burden on the tape drive, resulting in reduced maintenance.Features: built-in modular, expandable duplex multiplexing; accommodates up to 16 cameras; can be pre-programmed to record in multiple modes, including a super mode that has more than 500 lines of resolution.HSR-1 hybrid digital recorder Sony Park Ridge, N.J.OEM board Sharpens video imagesThe board incorporates real-time enhancement algorithms like those used on similar products but with a smaller kernel size. It is designed for end-users in law enforcement, pipeline inspection, industrial and military applications and medical imaging.

Features: size is 3x5 inches; can be incorporated into camera controller unit or used as a stand-alone, real-time image enhancement system. ValueVision V-Lace BoardDigiVision San Diego Transmission system Extends cable range A line of color video transmission systems can route video up to 10 miles over ordinary twisted pair cable, CAT 5 cable or leased-line copper circuits through a central telephone office.

Features: An unconditional refresh technique rapidly transmits 512x256 frames of color video, transmits a single NTSC color or RS170 monochrome video signal, can function as a splitter or multiplexer to transmit video from multiple cameras over a single pair.Color V-LINKNorthern Information Technology Inc.Arlington Heights, Ill.Improper camera output impedancecan cause problemsBy F.F. McCLATCHIEIn the past, CCTV cameras could be counted on to have 75-ohm source impedance, but recently there have been a rash of cameras on the market that do not. Such cameras exhibit an almost zero output impedance even though their specification sheets specify 75 ohms.The CCTV industry has chosen 75 ohms as standard for coaxial cable, and the majority of coaxial cables are either 50 or 75 ohms characteristic impedance.Since a coaxial cable must be terminated at both ends with resistance equal to its characteristic impedance to prevent reflections from impairing the picture, cameras must have an internal source impedance of 75 ohms, and monitors must have 75-ohm terminations.Problems occur when the camera has a zero source impedance, or if the 75-ohm impedance is left off at the monitor. The worst effects occur when both conditions are present.Ghost images and ringing - a white-to-black or black-to-white transition in the picture repeated many times in close succession - are two problems, and they become more evident as the length of the coaxial cable becomes greater. The ringing effect occurs with short cable runs of 50 to 200 feet. Obvious ghost images appear when the cable is 500 to 1,000 feet long. The first of many successive ghost images will be about 1/2-inch to the right of the original object on a monitor.Another problem caused by zero source impedance cameras is that signals placed on the coaxial cable to control pan and tilt of the camera will be shorted-out by the zero-ohm output of the camera and may cause remote pan/tilt systems and other equipment to work intermittently or fail.To test a camera for output impedance, connect a short 75-ohm coaxial cable to an oscilloscope, waveform monitor or CM-1 camera master. Place a precision termination (75 ohms) at the oscilloscope or meter. Measure the amplitude of the sync pulse. The sync pulse should read about 40 I.R.E. (0.286 volts peak-to-peak). Remove the 75-ohm termination. If the camera has 75-ohm impedance, the sync level will double (80 I.R.E, 0.571 volts peak-to-peak). A defective camera, however, will read almost the same amplitude with or without the termination in place.ABOUT THE AUTHORF.F. McClatchie is president of FM Systems Inc., Santa Ana, Calif.

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