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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 it's video switchers
that really turn you on...

Ten 'Must Know Things' about Switchers

We’ve already had a look through all the various options for using different types of video switchers, from the two camera input (which Doktor Jon has already suggested may be a complete waste of money),through to the most elaborate structured matrix, containing thousands of cameras and hundreds of monitors.

One particular option which hasn’t really been mentioned, is the obvious advantages provided by including audio as part of the CCTV system. Unfortunately, in the great scheme of things, there are very few good quality video + audio switching units on the market, so the possibilities for exploiting this relatively ‘low tech’ enhancement, have never really taken off as a viable option; which is a great shame really. Expect to see a far greater use of audio in the future (although it should be mentioned that in some countries and many parts of the US, it is actually illegal to record audio, without both parties consent).

1) The vast majority of desktop switcher units are available for between 2 and 8 camera inputs, with Sequential being the most popular.
2) When calculating a reasonable dwell time for each automatically switched camera, try and keep a complete cycle within 45 seconds.
3) Alarm inputs are normally open contacts, which require a simple closure contact to lock on to a particular assigned camera.
4) Some 2 output units, have one channel to provide a ‘SPOT’ display held on one camera, while the other is ‘SEQUENTIAL’ for all inputs.
5) Never use a ‘line powered’ output switcher, except with the manufacturers specified cameras; otherwise you may well regret it!

6) When selecting an appropriate switcher for your requirements, always allow spare channels for possible future expansion.
7) If the system includes video recording, you can connect the recorder or multiplexers output to the last spare channel on the switcher.
8) If you can, (subject to availability) always make a point of requesting video cables be fitted with solder, rather than crimp BNC plugs. It may cost more, but it’s worth it in the long run!!
9) In a complex multiplexed system, a simple switcher can provide an ‘easy to use’ level of independent control, for an untrained operator.
10) Take care when investing in a quality switcher, as you would any other system component. It may be simple, but remember it’s vital!

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