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keith

Need Advice on Fiber Setup

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I am helping with a camera system setup and need advice on the best way to feed video back and also be able to control the PTZ cameras. I have included a basic layout of my initial design.

 

Basically you see we want to feed 8 cameras (via fiber) to a single point out in the field and then bring feed the signals from those 8 cameras back to the CP via a single pair of fiber. This is done to save money by not having to feed the individual fiber runs all the way back to the CP from each camera. We do not want to run copper out to these cameras because of all the lightning around here (FL)

 

My questions are:

 

1. Can a single pair of fiber handle 8 video sources with no loss of signal and can we then control the PTZ functions of these individual cameras over that single pair of fiber from the CP to the point out in the field where the 8 cameras are fed back into?

 

2. What equipment is recommended to make this happen? We have Pelco currently and would like to stay with them as they have been great so far.

 

 

I am guessing we would need some sort of matrix switcher (w/ fiber modules) at the point in the field which would then feed back the 8 signals to the DVR and joystick controller back at the CP (via single-pair fiber). This single pair-fiber would need to be able to both feed the video and also enable two-way PTZ control signals between the CP and the field matrix switcher. Is this possible?

 

 

 

 

camlayout.jpg

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Yeah, actually the Pelco rep said it will be cheaper to run the fiber all the way back to the CP instead of buying trying to run them back over one fiber.

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Check NKF Electronics out, they are far more reasonable than Pelco for fiber transmission equipment. They also have the ability to stream multiple cameras over a single fiber, including data controls.

 

scottj

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data should know, hes the fiber guy, doing this with active cat5 is simple also.

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keith,

It's a few years since I last played with Fibre Optic gear, but one of the standard 'cost cutting' techniques, was to use one fibre to transmit a multiplexed display (i.e. your 8 cameras) and a second fibre for individual channel selection.

 

Now if you have a single two channel (i.e. two video input) multimode transmitter, you can pump both signals down the one fibre. If you increase the number of channels per fibre, then the cost tends to increase alarmingly on fibre equipment, and you also risk putting too many eggs in one basket.

 

In the past, I often tended to use quad (four fibre) cables, which at that time were not that much more expensive than pair cables. If you wanted to use low cost single channel fibre transmitters, you could use one 'pair' for video and reverse telemetry (RS 485), and a second pair for an additional video channel with one redundant fibre.

 

Even from your basic schematic, there are many options open to you, and it would probably require a lot more information (not least the length of cable runs) to determine what is your best option.

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I appreciate the responses. The actual distances aren't that great. From the CP to Cam 5/6 is probably no more than 2000'. We are using fiber to minimize any possible lightning damage to the whole system. Money for this project is less of an issue than doing a quality job.

 

I met with the guy pulling the fiber today actually and he will end up pulling all the way back to the CP from each camera so I guess my question has been answered. Great site by the way. I am going to stick around to learn more.

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Great, let us know what conspires. Also, if you dont mind, can you PM me the name/contact of the person pulling your fiber, i may need them for a job at some point down here, cant get anyone here that does fiber. Thanks..

 

Rory

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Hey Rory...

 

I can pull, terminate, and certify all the multi-mode fiber you want. I just don't have a grasp on the media converters needed for cctv.

 

So if you know what equipment to plug the optical fiber into we're good to go mon.

 

Even with the extra airfair from California vs. Florida I could probably still save you some money.

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cool thanks .. well the whole fiber thing is something i need to look at closer, GE has fiber nodes but they arent cheap .. .maybe there is something else out there ..?

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GE?

 

i need 53 cameras run on Fiber, back to a main point ... 2 miles along cameras, another 1/2 mile to the main point ... any ideas ?

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Yes rory, G.E. You need to get a rack w/ termination cards. Many sand dollars. Last big job I did with fibre was about 2 1/2 years ago...255 cams-Medical Center. Took 1 year. Access, intercoms, it was a sweet gig.

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So i have the GE price sheet, do i just pick say several 16 channels or whatnot and use that kind of configuration? Bringing one fiber cable from each camera or at each camera join into one main fiber ... its 52 cameras mounted 200' away from each other for 2 miles, a perimeter fence.

 

tanks ...they gots plenty sand dollars for this one ..

 

Rory

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Sounds like a nice gig, congrats. The cards in the head end held 32 cams a drawer (4U). There were 7 full racks for all equipment. Fiber was terminated in a termination box, then ran fibre jumpers to the translators (so there isn't a big mess in Rack). They were then translated to copper and into your usual (preferred) CCTV setup rig. In the Field, ran fiber to a center point (Fiber Term Box) for each block of cams, then put translators there, ran copper to cams…easy? Oh yea, leave yourself @10 feet (fibre) at each end and circle the fibre.

 

Oh, and it was Multi strand with spares.

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Nice job rory

 

Agree with Data about using fibre points (nodes) and then using copper to individual cameras (arranged as groups of perhaps 6 cameras per node).

 

A couple of points to have a think about; for every 150 metres ( yards) or so perhaps allow 5 metres of looped fibre to be hidden away. If after installation the cable gets damaged, you've then less of a problem pulling the bits togethor to effect a repair. Have a think about whether you are going to be able to repair cables if they are damaged.

 

Doing field repairs on fibre is a lot more challenging, than repairing copper. And make sure whoever is pulling the fibre a] knows what they are doing, and b] is prepared to accept responsibility for what they are doing! If they break the fibres, they will have to put it right!

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Yes, if subcontracted, make sure you put a stipulation in contract that all fibre must be tested upon completion of all runs-with your approval. One little nic/crack in that glass and you're in that creek w/o a paddle.

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