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The short of it, wire has resistance to it which makes the voltage drop from what's being supplied, to what's being seen by the device at the end of the wire. In other words, a power supply might be supplying 12 volts, but some of that voltage is being lost over the wire so the device on the other end might only be seeing 10 volts. For the simplicity of things, we'll go ahead and say AC works the same as DC but the reality is wire resistance (known as impedance in the AC world) has a lot less of an effect on AC so the voltage drop is less compared to that of DC. I only point this out because we're usually looking at 12VDC or 24VAC for cameras (analog cameras always used 24VAC, hence the reason most modern cameras can accept it) The long of it, according to the NEC an 18 gauge wire on average has a resistance of 7.77 Ohms (measure of resistance) per thousand feet of wire. Voltage is current (amps) multiplied by resistance (Ohms). So if a device draws 1 amp on a 1000 foot run of 18 gauge wire, we can calculate our voltage drop by using 7.77 Ohms * 1 amp = 7.77 volts lost over the cable, so the device at the end of a 12 volt run is only receiving 12-7.77 volts or 4.23 volts. In other words, it won't work. Same device at the end of a 24 volt run is seeing 24-7.77 volts, or 16.23 volts. Depending on the devices rating, this may or may not work. PoE devices operate at 48 volts to compensate for the voltage loss over the smaller gauge wire. Now for the heat... a camera should produce roughly the same amount of heat regardless of if you supply it with 12 volts or 24 volts. Heat is directly connected to how much power is used by a device, power is measured in watts. Watts are calculated by multiplying voltage by current. A device doesn't consume a fixed amount of current or voltage, but it consumes a fixed amount of watts instead... this means there's a balancing act, we supply a set voltage to a device and it'll use the current it needs to get to the watts it needs. So watts and voltage are fixed, current is variable. The more voltage we supply to a camera, the less current it draws, for example if a camera has a power consumption of 5 watts, and we supply 24 volts to it (we'll leave out the voltage drop discussed above for simplicity, but this also explains why shorter or longer runs have no effect on heat), we know the current is watts / voltage, or 5/24 = .208 amps. If the power consumption is 5 watts and we supply 12 volts then our current is watts / voltage, or 5/12 = .416 amps. So at less voltage, we're using more amps, and you'll notice your power supply can only provide so many amps! Regardless, our fixed number is 5 watts. Heat measured in BTU's can be calculated directly from watts using the formula BTU's = watts * 3.41. So if a camera is 5 watts, regardless of the voltage we supply to it, or the current it draws, it'll be producing 17.05BTU's which is our measurement of heat. That's kind of basic electronics 101 in a nutshell... Also, the camera will have a built in regulator so you can plug in 12 or 24 directly to it (if it's rated for it!) I'm looking at a camera right now that will take 12-48VDC or 24VAC, so I connect 32VDC directly to it if I want and it should work. So now that I've thouroughly confused anyone still reading this... 24 volts works better, especially over longer runs, just take our word for it, heat won't be an issue, again, just take our word for it, and the camera will say what voltages it can directly accept, supply a voltage anywhere in that range.

Each camera uses a different amount of bandwidth depending on a number of factors, megapixels, images per second (ips, as opposed to FPS), compression, etc. you find all this out from using tools available from the camera manufacturer. Because of this, the design for your CCTV system will now focus on the network because this is the area you'll trip up. The cameras are straight forward, powering them are straight forward, connecting and recording them are straight forward, the transmission of the data needs to be given special consideration though. For example, an Arecont AV2155 2MP H.264 dome with default qaulity at 10 IPS uses ~2.5 Mbps. An Arecont AV8365 which is a 360 degree camera at 10 IPS will use ~9.5 Mbps. Some 5MP cameras can get up to 30 or 50Mbps! It all adds up quick. If you design your own security network, it's not a big deal you just need to understand the bandwidth you need and what the switches you put in the project are capable of. 100mbit ports, gigabit ports, fiber uplinks, etc. If you are using a customers network, you need to start working with their IT group from day one. They need to know every location you need a network drop, and how much bandwidth is required at that location for all your cameras going back to it. They also need to know the PoE requirements if there are any. Other considerations are the IP addresses you need, and in return they'll often want the MAC Addresses for all the equipment you're going to put on their network. I'm really making it sound a lot more complicated than it is... best way to learn is by throwing out a few scenarios I guess and getting recommendations or critiques of your thoughts on the design.

It depends on all this. The camera manufacturers have storage calculations you can go through to get a decent idea of how much storage you need for what compression with what cameras at x% motion for x amount of days. Then you can build your NVR around that.

Air makes an excellent insulator, which is why long rural power line runs will never be buried. You have a lot of power loss in the ground, and when it's wet and the soil closes in or water fills any gaps around the line and cracks in the insulation, power will be seeping out in the ground which is conducting which will lead to signal loss. Power companies have to plan for this constant loss from buried cable. Works the same with anything conducting electricity in the ground... another advantage to using fiber is you don't have these problems.

http://www.arecontvision.com/nvrintegrationmatrix.html On that list I've used arecont cameras with genetec omnicast and a few others with great success. None of the ones I've used are free and or offer demo's that I know of though.

The surfboards are very solid cable modems. Rare to find anything comparable. I've had a lot of junk DSL modems in the past...

IPv6 has been coming since the late 90's, but we didn't officially run out of IP addresses until a few months ago. The IT industry really dropped the ball on the migration... should have been done ten years ago when it would've been a lot less painful. There's a translation for IPv4 to IPv6 but the idea is with unlimited IP addresses IPv6 provides, we won't need private networks (or private IP addresses anyway) and NAT with all it's quirky problems can be done away with. Networks will be isolated by firewalls, vlans, etc. but not by private addresses. Because of all that, the 192.168.x.x concept will be done away with. I'll be surprised if we ever actually switch though.

It's been my experience with using these cameras on other systems, as long as you tell them it's an av8185/8365 they'll give you the multiple licenses needed but only charge you for a single license.

Look into ZoneMinder. It's really going to depend on your hardware though, if you are using analog cameras and your capture card is supported in linux then you're good to go. Alternatively if you're using network cameras and the models you have are supported, you're also good to go. The software will take care of question number 2.

It's tough to discuss one without straying into the other. Soundy, I was avoiding bringing up baluns, all very good points. General consensus seems to be 4 twisted pairs in a single jacket offers a lot more opportunities than a single wire with a conductive shield. To each his own though, do what you're comfortable with, It's not like there's a right or wrong way.

City of a million cctv cameras, people seem to be desensitized to being on camera everywhere and ignore them? Forget about them? They seem to have lost all their effectiveness as a deterrent and now simply record the carnage... just not in as good of quality as the news cameras and the youtubers. City where only the criminals and the cops have guns, leaving everyone else defenseless. If people rioted here they'd target businesses but would think twice before kicking down anyone's door because who knows what's on the other side. I'll take my sig over a cctv cam for protection any day of the week.

Realistically cat5e is good for 300', rg59u for 700'. Anything over that, and you're buying media converters and going on fiber. Thing is, coax is home run, network switches can easily be distributed making my network runs shorter and using less cable in a lot of cases. Even if fiber is needed in your network, you can get switches with fiber ports built in so you eliminate the media converters and go just on fiber, not to mention you can have 10 cameras going to a single switch riding two strands of fiber back to your main switch at the head end. This becomes huge when you're talking about a single cctv system for multiple buildings. You really open up the design possibilities to cut down on overall cable lengths and create a fully distributed system over a very large area. Again, all of the above really starts to add up as the systems get larger. If you're talking about a small office or something with 16 cameras then coax will probably be cheaper/easier.

5 years ago the cost of IP cameras was prohibitive, I don't think that's the case today. Same with PoE network switches, and on a lot of projects you can connect to the customers network so you're just specifying to the network group what you need... drops the cost significantly. Also when you get away from purpose built DVR's the cost savings makes up for the software difference. Real estate is expensive, and analog cabling/head end equipment takes a lot of real estate. I think Cat5 simply has a lot more capability than Coax. Data, power, video... all in one jacket. One connector at each end either going to a camera or a switch to accomplish everything. Honestly for any system over 16 cameras I'd push for IP, and any system over 32 cameras I wouldn't go any other way.

IP cameras are: easier to install - plug into a network, no encoders, no splitters or looping matrix's, etc. easier to power - PoE easier to control - no data cable for PTZs to deal with more flexible - remote cameras? no problem. Also don't need a card plugged into a dvr, can order a server from anyone and plug it into the network, install your software, and done. easier to expand - can run a cable back to any network room 300' away and attach it to your cctv vlan any time, and you're not limited to how many channels your dvr has as it's based on camera licenses with the head end software. You can also connect cameras directly to the customers network provided they have the bandwidth. less space - you cut out a lot of head end equipment and power supplies. and megapixel progressive scan IP cameras produce a far superior image to a 480 line (or 540) interlaced analog camera. if yours doesn't, you need a new line of cameras. The new 180/360 degree megapixel cameras with multiple imagers basically have obsoleted PTZs for most applications. Can't attest to the low light conditions, always use flir thermal cameras when it's an issue, and it's rarely an issue with businesses as there's usually plenty of outside lighting. For residential though, analog cameras are more than adequate and more economical. Again, that's all my "strong" opinion. I deal with larger projects typically so economies of scale kick in for me, probably not applicable in residential or many small business installs. I've done systems with 200+ IP cameras coming back to network switches connected by a fiber backbone, with the head end equipment only taking up a few racks and the security console only containing a few workstations and a lot of large monitors. Very simple, very clean installation. On the flip side I've done systems with 200+ analog cameras with giant bundles of rj59, fiber (for the cameras to far away), along with 18 gauge power cables and 22 gauge ptz data cables running into 4 racks full of fiber modules, matrix bays, and termination panels along with 2 more racks of expensive proprietary dvr's. You can imagine the space and cable required for this... compare that to the IP solution with a single fiber bundle running into the head end.

At the end of the day, IP cameras using cat5 will destroy any analog camera using coax in my opinion. For business customers, if you put in cat5 and use baluns with analog cameras, you have provided an upgrade path for your customer to switch to IP cameras in the future without a complete installation, but just replacing cameras and head end equipment. To me, that's worth it. Otherwise, might as well use the cable spec'd for the camera which is going to be coax for an analog camera.

That's one thing I miss about my little s**tbox Mazda - same concept: "You car is worth $40,000, my car is worth $400... *I* have the right of way!" We have a saying around here... doesn't matter what you drive. Company car always wins.

As long as you get a 1080p tv it'll look great as a monitor and the picture quality will be just fine. We use them all the time with vga inputs.

Completely depends on the site (or type of site I should say...), but 90% of the time they go into an IT closet if one exists, and IT closets always have some type of access control or lock. On the rare occasion they get stuck in a managers office somewhere (this is on smaller sites like a coffee shop or gas station and this is the most likely place it'll be stolen). Ask the insurance adjuster what they spent on the DVR in their office.

The most noticeable problem with that smart car is the steering column is on the wrong side.

Couple of ways to do it, all expensive. Could switch to PoE cameras, and put a hoffman can every 150 meters with 120vac power, along with a power transformer and a network switch with multiple ethernet ports and a fiber uplink, then you're just running riber out to a can every 150 meters, and cat5e to each camera within 100 meters of either side of the can. Second way would be similar, put a can every 150 meters or 300 meters with a power supply and coax to fiber converters, running fiber out to each can, bunch of fiber converters back at the head end to convert it back to coax. Something like American Fibertek or Comnet have what you need for the fiber components. If the 3km is lighted, you can mount the boxes on the light poles and pull power from the light poles, but you'll need some type of step down transformer. Bottom line is it'd be a star configuration to minimize the amount of cables running back to the head end. Depending on the perimeter, you could also put multiple cameras in a single location with different lenses to cover a very large area... this would significantly reduce your cable.

I'd want 4, 360 degree 8mp panoramic fixed IP cameras ( http://www.avigilon.com/products/cameras-video/panoramic/ or similar), along with 4 flir infrared cameras ( http://www.flir.com/cvs/americas/en/security/ae/sr100/ ) connected to some serious video analytic software. Of course, it'd probably be cheaper to hire batman as a security guard...

End of line concept doesn't really apply to video cameras. Since the cameras are constantly streaming data, the DVR knows something is wrong immediately when the steam stops. Either the camera is broke, the cable was unplugged, or in this case, the cable was cut. End of line involves putting a resistor (or in some cases, a capacitor or a diode) at the end of a cable to supervise it. The head end equipment constantly monitors the cable for whatever resistance is in the end of line resistor, and if a cable is cut (or a normally closed dry contact opens up) that resistance will go to infinity so the head end equipment knows something is wrong. Likewise, if the resistance drops to around zero because of a short in the wire (or a normally open dry contact closes), then the head end system knows something is wrong. This is useful when you want to supervise devices like fire alarm strobes, door position switches, motion detectors, etc. But with devices like CCTV cameras that constantly stream data, or devices like servers which constantly talk back to the head end, it's not needed.

What's the field of view for the PTZs? You might be better off scrapping them and putting in a bunch of these 5mp fixed cameras: http://www.arecontvision.com/AV5155.html Or alternatively these 5mp fixed cameras: http://www.avigilon.com/products/cameras-video/ip-dome/ They might be pushing your budget but they should get the job done and have excellent picture quality. Just make sure they're compatible with the nvr software you choose.

hi both cameras are POE. Only if he pulls cable back to the head end. If he goes the wireless route, he'll need 120vac at each location.

Most of these products are made for situations where you need to reuse existing conduit or wire. They also provides a good upgrade path, gives you the ability to easily expand the system in situations where you can't easily run new cable but want to add a few extra cameras. I personally wouldn't ever use it in new construction unless I had some constraints from something else, but I also wouldn't use analog cameras anymore unless I absolutely had too. To each his own though.