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Guide to Closed Circuit TV (CCTV)

So would you like to play "Spot the CCTV Camera?". Eagle eyed visitors may recognise the profusion of street furniture, surrounding a single heritage dome camera keeping watch over part  of Londons' prestigious Oxford Street shopping area.

If you need to handle
multiple images ....

The mystery of Multiplexers

The term multiplexer has actually become a generic description for a particular type of equipment, and yet the word actually has a very well defined meaning. For example, with a line powered video camera, the power supply is carried to the camera in one direction, whilst the output signal returns on the same co-axial cable, in the opposite direction. So multiplexing, is in effect using one medium to perform a number of discreet functions.

In recent years, a multiplexer has become the universal description for any device that can handle (display or record) a number of signals at the same time; so in practice, we can say that there are Display Multiplexers and Record Multiplexers (each a simplex unit). Some models will quite happily perform two or three functions at the same time (duplex and triplex, right up to penta and hexaplex!).

To help you get to grips with a myriad of differing devices, and perhaps more importantly how best to exploit them, Doktor Jon has a few suggestions which you may just find of interest.

Picture in Picture (PIP) units - The humble ‘Picture in Picture’ unit, hardly ever used, but surprisingly useful in certain situations.
Quad Display Multiplexers - The easy way to display 4 images at once.
Display Multiplexers - Capable of splitting a screen into eight, sixteen, or even more ‘thumbnails’, without the use of a safety net!
Record Multiplexers - Lots of cameras recorded onto a single machine, the perfect solution or a perfect disaster?

Screen Splitters - Digital may indeed start to reign supreme, but analogue isn't totally dead yet ..... long live the analogue.
Computer based multiplexers - Is a well ‘ard disc based machine really man enough to take on such a demanding role?
10 ‘must know’ things about Multiplexers - They may be complex beasties, but even a basic multiplexer can hold a few surprises.

How to get the best from a Multiplexer - Understanding technology is half the battle - use it properly and you may just win the war!

An alternative view for a multiplexer - The use of multiplexers can dramatically reduce the cost for larger CCTV systems.

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