CCTV systems have been extensively used as not only a crime prevention system (due to its deterrent value) but also as an event recording medium so that incidents can be reviewed after they have occurred. The most cost effective methods of recording however have traditionally been analogue based video cassette recorders.
Unfortunately CCTV users occasionally forget to change video cassette tapes, resulting in the failure to recorded images of the events being monitored. Another key issue with conventional analogue systems is the extensive time required to review recorded material, which ultimately results in the recorded footage not being reviewed.
Digital systems - a logical choice
To resolve these two basic problems one needs a recording system that requires as little human interface as possible. It should also have sufficient storage capacity to record for extended periods, before automatically recording over previously used storage space. The system should be relatively simple to use in order to retrieve information at a specific point in time and review previously recorded footage.
Obviously digital systems offer all of the above and more.
The largest barrier to such digital recording systems has primarily been price followed by reliability and performance. However, with advancements in computer processing speeds, extended digital storage capabilities, as well as ever-reducing prices, digital storage mediums have become far more feasible as an effective CCTV recording device.
Grundig's digital solutions
The Grundig DMS-180 for example retails for about R49,950, which includes a 9GByte Hard Disc (SCSII) drive. The unit's storage capability can be extended to 108GBytes with the facility to down load compressed information onto other archiving systems.
Once installed it can be left unattended to recorded continuously with little or no human interface. In fact, the only interface for reviewing can be carried out directly from a PC workstation. Since the Grundig DMS-180 has a full network interface and operates on the Windows or Window NT platform, it is extremely simple to use, being operated from a GUI environment just like any other application.
Other advantages of these digital systems include the ability to record high-resolution pictures repeatedly onto the same hard disc with no picture deterioration nor any build up of residue onto recording heads that occurs with analogue video recorders. The Grundig system's hard disk drives are quoted as having a MTBF of 300,000 hours which will give years of trouble free recording.
Integrated switching
Included in the price of R54,000.00 per unit is an integrated switching system, similar to a multiplexer, which also includes movement or activity detection for event recording. The Grundig DMS-180 can be expanded to accept up to 18 video inputs and has two composite video outputs, which provide high definition pictures onto standard CCTV monitors.
Unlike analogue systems the Grundig DMS-180 has the facility to safely record alarm events to a partition on the hard disc which will not be overwritten. In this case, the unit can be set up to record the pre-alarm events, the alarm event, and the post-alarm event for a certain time period. Then this track is safely recorded. The unit can also change the recording frames/second of alarmed cameras to user predefined rates, to ensure more pictures/second are recorded in the case of an alarm.
Once recorded, the reviewed pictures can be simply exported to stiffy disk, LAN, WAN or Internet for immediate distribution and printing. The recorded information can also simply be imported into document and reports in their standard formats.
Grundig also offer a triplex digital hard disc recorder, typically installed in casinos, where real-time recording is a key criteria, as well as the review process without interrupting the recording capability of the machines.
For details contact Cliff Rose of Modular Communications on tel: (041) 312-653 or e-mail: modular@global.co.za.
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