Installing Video Cameras on a Parallel Network
Once it has been determined that parallel conductors are available between the horizontal cross-connect and the main cross-connect, and the conductors have been tested for suitability (see â€œUsing a Parallel Network for a Video Camera,â€ SDM, July 2005, p. 88 or www.sdmmag.com), then security technicians can begin the installation of network cameras on a parallel network, connected to available UTP backbone pairs.
The horizontal UTP is pulled from the camera location to the telecommunications closet, with male RJ-45 plugs installed on each end. If only one camera is being connected to that particular horizontal cross-connect, its cable can be plugged directly into the parallel backbone UTP for data transport to the main room. If more than one camera, video server, or IP-addressed security device is being connected in one closet, the installing company would place a hub or switch with sufficient port quantity in the closet. This device requires AC power, and its transformer would preferably be connected to a UPS.
Once the cameras are connected, properly addressed and programmed, their video signals will be available on the monitoring computer, once it is connected to the selected backbone UTP within the main connection room.
Fiber HookupThe connection to available fiber backbone conductors is similar to the UTP example, with the addition of a pair of fiber-to-UTP media converters, which are simple, non-programmable devices that retransmit Ethernet UTP signals onto fiber, and change the optical signals in the fiber to electrical Ethernet data on the other end.
As with the UTP parallel system, if more than one security device needs to be connected within a single horizontal cross-connection room, the security company will need to provide a switch or hub with the proper number of ports. Once the cameras are connected via UTP to the switch/hub, a UTP patch cable is used to connect the switch to the media converter.
Fiber Media ConvertersThere are many manufacturers of fiber-to-UTP media converters, and each provides many different devices. The proper selection of a media converter requires knowledge of the type of fiber in place, how many fibers the client will allow you to use, and the overall length(s) of the fiber cables to be used.
Multimode fiber is used for distances less than four miles. Multimode fiber will be labeled on the jacket as 62.5/125 or 50/125, which indicates the sizes of the fiber core and cladding in microns, which are millionths of a meter.
Fiber labeled 9/125, 8/125 or 10/125 is the singlemode type, which is used for long distance and high bandwidth applications.
Media converter models are differentiated by the type of fiber (multimode or singlemode), number of fibers needed (one or two), the maximum distance over which they can communicate, and whether the devices will transmit 10, 10/100, or 1,000 Mbps Ethernet. Fiber media converters that use two fibers are less expensive than those that use a single fiber for communications.
Once a media converter model is selected, remember to order one for each connection end, along with appropriate power supplies.