Fibre Optic systems "for dummies" (hopefully ok to ask) - coaxial testing

[therunningbruce]

Hi,

Sorry if this basic questions and not approprate please delete..(sorry)

I am a project engineer without an EI background. but a moderate experience with this..

I'm looking to get a background basic understanding of capacities and system setup.

Why I am asking:

​

> Site project to upgrade a CCTV project with an exsiting Fiber optic "backbone"
> The back bone is fibre but the actual cameras are coaxial cables (so very old pre 1996 !).. so really needs an upgrade !

So my questions are.. ( i appreciate the vendors will do a lot of this work but it really helps me on projects to have a background understanding)

​

> What tells me if a system fiber is multimode or single mode? (labelling of cables / convertors ..)

I Can generate a list of cameras and their bit rate..
Fiber testing
> what tells me if a fibre is enough for a high resolution camera to a patch panel (say less than 100, 200 ,400 meters)
(or is this dont be stupid questions if its a fibre it has tones of capacity)
> when i send a signal from a datacenter( computer the Brian of the cctv) to a monitoring system..is that a single fibre multi fibre..?
> are all fibres equal.. say is a 1996 cable the same as a 2023 cable ? and how do i know.. whats the difference?
> if its an old cable can it be tested for capacity ? or how "good it is"
> are testing binary..e.g. pass fail or capacity..? or a shade of grey..

Coaxial cables
> ive a bunch of broken CCTV cameras..
Can i attach a "widget" and simulate a CCTV green screen to validate my CCTV Fibre is good through to the operator so i can just replace the camera on the fibre to coxial convertor.


sorry if this too basic for this forum..

thanks ..

james

 

[djs]

Look at the fiber cables and the manufacturer's markings. The manufacturer, if still in business should be able to tell you if multi or single mode. Lacking that, see if the cable has one of the following markings:
62.5 um, 50 um, OM1, OM2, OM3, OM4. If so it is multimode. Single mode will be marked 9 um. You should also have fiber to copper converters at both ends. Looking at those should also indicate single or multimode.

Camera resolution would be linked to fiber bandwidth. This is usually specified in Mhz per kilometer. This is a fiber specification that can only be found on the manufacturer's datasheet for that cable.

Even today not all cables are created equal. For example 62.5 um or OM1 cable has less bandwidth than a 50 um OM3 cable. Testing for bandwidth is complex and expensive. You will need to hire a specialized testing company to perform that kind of test. They can also test the cable for defects which is a much simpler task.

To simulate the CCTV signal you will need to know how the video is encoded on the coax. The data sheet for the cameras should tell you that.