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Buying a CCTV system and what you should know part 2


Now this is a continuation of a previous article…..

In this article buying  a CCTV system and what you should know part 2 we are going to cover the new High Definition over coaxial market.  With this new technology you have a lot of great features that have helped to push the old analog technology to the way of the eight track tape, cassette tape, VHS, and the HD DVD.  All of these previously stated technologies, while good in their time were replaced by better, more efficient technology.  With new High Definition over coaxial technology, you currently get the ability to send 720p and 1080p video signals down the same line that you used to only be able to send analog signals down.  Now the reason I say you can currently get 720 and 1080, is the fact that it is being worked on to be able to send up to 8MP or 4K resolution up these same cables.  Now this technology is not available in the United States at the moment, but there are plans to get it here in the second quarter of 2016.  This will be a game changer for the coaxial cable installations, but will always take a back seat to the resolutions that IP (Internet Protocol) systems will be able to produce.  The reason for this, is that the data limitations of coaxial cable will always be the same, where there is essentially no data limitation with Cat6 cabling.  I say essentially as we have not reached a limitation on a single camera run, now if you add a large amount of cameras that funnel into a single switch and then funnel down the pipe you will have a data limitation.

I have previously described in another article the differences between the newer HD over coaxial technologies in articles such as,  “TVI vs. CVI, What is the Difference?“.  If you want a little more in depth information on HD over coaxial cable CCTV systems, I highly recommend reading to help better understand the technologies.  I am only going to cover some of the basics of this technology and those articles go in depth as to the differences between the competing technologies.



One of the nice things about this new technology is that you can utilize your existing cable infrastructure and obtain the High Definition video quality from your CCTV System.  Now there is a caveat to using your existing cabling is that if you have old pre-made cabling you will be limited on the highest video quality you can get.  For example, if you do use this cabling you will want to stick with 720p setups or your image quality will suffer.  This being said, your video will still be better than your old analog system could be.  With a DVR (Digital Video Recorder), not like your cable DVR,  you will run all of your camera cables all the way back to the DVR.  This is called a home run as the cables go from the point of the camera location all the way home to the DVR.  At the DVR location you generally will have the power supply to power the cameras, but on longer runs some installers will opt for power supplies closer to the camera location to prevent voltage drop.  With voltage drop you may get a camera to function, but the question is for how long.  The industry and electrical standard is for no more than a 10 percent drop in the voltage from it origin.  So if you are sending 12Vdc, you should have no less than 10.8Vdc at the camera side, for the camera to operate.  If you are exceeding this, then you may want to think about upgrading your power supply to a 24Vac supply to increase the distance.  If you do decide to need to upgrade your power supply make sure you either have dual voltage cameras which can handle 12Vdc or 24Vac or you simply use a 12Vdc camera with a down converter at the camera to convert the 24Vac down to 12Vdc so the camera can handle it.  If you simply use a 24Vac power supply and hook a 12Vdc camera up to it, you will fry the camera and be stuck buying another camera as they will not be covered by any warranty.

Now all of this being said, don’t get scared! This was said to make you aware of potential risks and inform you. Another very nice thing about using a DVR setup is the fact that there is literally zero video latency associated with it.  This may not be something most people are aware of, but video latency is when there is an object moving in front of the camera you see it in real time.  With an IP camera setup you can get some video latency and depending on the amount of cameras and bandwidth being used internally this can be from as little as a fraction of a second to as much as a couple of seconds.  This is highly important in a retail environment especially if you are following someone or something around trying to make sure there is no theft occurring.  You don’t want to give the perpetrator time to get away before you catch what they are doing.  With the DVR setup, this is a nonissue since the video is being encoded and decoded at the unit itself allowing for a live view of your location.  Now if you are remotely viewing any system from analog to IP you will deal with latency as it needs to be transmitted remotely and captured and re-outputted to the source you are viewing.  You will have several factors in this type of a scenario.  You will have the upload bandwidth at the site you are remoted into, the download speed at the location of the remote viewing, and any other network traffic across the World Wide Web.  For most people, they do not expect that when they are watching remotely to have it 100 percent real time, but there are some that have to have it as real time as possible, and for those people I suggest a direct fiber link between locations to prevent this as much as possible.  I have only begun to scratch the surface, so check back for a continuation of these articles.