nvt products with punchdown blocks

[karnos 0]

Hi Guys

 

I was looking on NVT web page. I notice couple nice devices and I also noticed that they can be connected through the punchdown blocks. Have anyone ever tried it, and if yes how far we can go with it and how good was the picture quality. Basically what I want to do is to use these punchdown block and a single cable, than I want to use NV-862R to receive the signal (and connect it to DVI) and conncet 3 cameras to NV-452R through RG59/U cable, and that would go through a punchdown block and than to the NV-862R. The only problem is that the distance from NV-862R to the farthest camera will be about 1000 or 1200ft, and I don't know if the punchdown block will decrease the distance or not.

 

One more question. In this design I'm mixing RJ-45 cable and RG59/U cable, is it possible to just use RJ-45 cable all the time (I know that NVT doesnt have 4 port hubs to connect RJ-45 cable, or maybe I don't know about them).

 

I know it's a little bit complicated but I hope that we can solve this problem.

 

Thanks for help

[vf702 0]

I will try to break this down a little bit to make it easier to digest.

 

NVT, Nitek, and some other companies make baluns that allow a CCTV signal, which is commonly transmitted up a coax line, to be transmitted over an unshielded twisted pair (UTP) cable. Examples of UTP cables include CAT3, CAT5, and CAT6 cables used in telephone systems and computer networks. A CAT5 cable used to connect a computer to a network switch containes four pair of cables inside it. Each pair of cables is two 24 gauge cables that are twisted on eachother. So the commonly found CAT5 cable is actually an overall cover with four groups of two cables wrapped around eachother. These cables also come in a variety with shielding around the cables. These are called STP or shielded twisted pair. For telecom or in this case CCTV signals to travel over the twisted pair, the pair needs to be unshielded. An overall shielding is ok to protect the inside cables from moisture or rodents (in the case of direct burial cable). RJ-45 is a connection type that is commonly used for computer networking. If you have a network cable plugged into your computer, it likely has an RJ-45 style jack, which plugs into your network card.

 

I may be corrected on this part, but I believe that the baluns change the Ohms of the signal from 75 to 100, so that it can pass on the twisted pair cable. They simply change the signal so that it will work on the different type of cable. One balun to change it, then one to change it back.

 

Punch down blocks are a device that has been designed to organize and easily cross connect different pair of cable. In a typical Private Branch Exchange (PBX), such as the private phone system that most larger businesses or schools have, Only one pair of cable is needed to transmit a phone signal. Thus a single four pair CAT5 cable has enough pair inside to run four phones. In large systems, the central phone room has small branch stations. The local phones run to the branch station, which is then connected to the main phone room. Instead of running two hundred separate cables from the main phone room to a distributed closet, a two hundred pair telco cable would be used. The punch down blocks are used to organize the wiring so that when a phone in the north building is connected to the branch station position 56, a connection can then be made in the phone room for position 56 on the north branch to the actual main phone system. Blocks provide minimal resistance to the cable run.

 

For a CCTV application, you can connect an NVT transmitter such as the NV-214A-M directly to each of your cameras. Then run a CAT5 cable to the control site. At the control site, you can use a passive receiver for up to 750 feet or an amplified receiver, such as a NV-652R, for longer runs. The amplified receiver will then connect to a short coax run to the monitor, DVR, or wherever you want the video to end. NVT makes single units, four camera units (NV-413A, NV-452R), eight, sixteen, and thirty-two camera units. You can connect four NV-214A-M's to a NV-452R. The multi-camera units work as the individual units do, just in a more organized case.

 

You also mentioned a DVI output. The outputs on the NVT equipment are a BNC type. If you would want to run a single camera to a plasma TV, you could probably find a converter somewhere, but I do not believe that the resolution of any standard CCTV camera would look very good stretched to that resolution. There are other strings in this forum that have dealt with connecting DVR's to plasmas with some success. I would recommend viewing them.

[karnos 0]

Hi vf702

 

No offense, but you didn't tell me anything new. I know the specification of the cables, and UTP has 100 to 120 ohms. And I also know that you need to use a coax connection to connect these adapters to the cameras and DVR. My question was are we able to split the signal from RJ45 through a punchblock without any visible losses with a distance about 1000 or 1200 ft. Another question that I asked was if NVT has something else than NV-452R that translates BNC to RJ45. I just want to use RJ45 all the time and if I will use NV-452R than I have to use both, and I dont want to mix. The perfect solution for my problem will be NV-704J-PVD, but that one sends not only video but also power and PTZ.

 

The thing that I want to do (and I probably repeat myself), like in the networks. You connect two swithes together and you are able to use a single cable between them and than split it to more devices (like a star topology). Any ideas about it?

[CollinR 0]

You can but not with just any "punchdown". Going across a classic POTS 66 punchdown, no way. Using a punchdown on a RJ45 jack on a patch panel yes but with some degredation. Anytime you add connections to basically and kind of transmission you degrade the signal.

[kensplace 0]

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