Thursday, July 31, 2008
Digital video recorder (DVR) is a device that records video without videotape to a hard drive-based digital storage medium. The term includes stand-alone set-top boxes and software for personal computers which enables video capture and playback to and from disk. The DVR provides a convenient, if limited, replacement for the multiplexer + VCR combination and provides non-linear access to recorded material usually selected by camera ID, time and date. The consistency of quality of recorded material will in general be higher than that obtained with analogue tape although the actual quality achieved may or may not be better, depending on the compression algorithm and individual configuration.
In general more programmable options for individual video stream recording parameters, (picture resolution, number of frames per second, trigger options, start/stop times etc), are available, but a DVR is only useful where the analogue cameras are all cabled back to the DVR’s location. Competent DVRs now feature UDP (CAT 5) network ports so that the device can be provided with an IP address and thereby become accessible over an Ethernet network. It uses a single IP address to access thousands of cameras without loading your network. It's easy to set up and use.
Wednesday, July 30, 2008
The time lapse recorder is one of the most important components of a surveillance system. Time lapse recorders are highly durable recording machines made to operate 24 hours a day 365 days a year using standard VHS tapes. These professional recorders are made with the finest quality parts and industrial decks. Some of their main features are event reordering, super fast time and date search, time and date generator and real time recording.
Network IP cameras connect to a computer network. They each have respective nodes, or network addresses, and act as video servers on the network. This allows a user to view the video from any computer equipped with a web browser such as Internet Explorer. No special cables are required; network cameras can plug in to any computer jack available on the local network. Surveillance can thus be handled remotely from anywhere in the world, so long as a user knows the IP address of the camera. Numerous protocols are used depending on the make and model of the camera, including TCP/IP, HTTP, and FTP.