Connecting Multiple Wired Cameras
How can I connect multiple wired cameras?
In a wireless system, all the cameras send their video signals to a single unit (the video receiver), and that unit connects to your monitoring device (television, VCR, computer, etc). Wired cameras are designed to wire directly into the video device. Thus, to make a multiple wired camera system work, some extra hardware is needed.
The first, cheapest approach is to get several RCA Y-cables, which have an RCA connector at one end, and two (or more) on the other. Use the cables to 'splice' (connecting each to a camera and to the next Y-cable) the separate wired camera connectors to the video input jack on your television, VCR, etc. Alternatively, you might be able to find a video splitter box, which works exactly the same way, but the Y-cables are enclosed in a box. With the cameras all connected this way, the system switches between cameras in the same way a wireless system does.
A second approach is to use a video switch (or video selector). This will allow you to see one camera feed and change cameras. Video selectors are commonly available in electronics stores as a way of hooking up multiple DVD/VCR/video game systems to a home entertainment center. Using a video switch is not recommended, because it is the ONLY way to switch between cameras. X10 remote controls, motion detectors, and software will not be able to cycle between them using X10 Commands.
Lastly, you can use what is called a multiplexer, or sometimes a quad processor. This has multiple video inputs and a single output, much like a video switch. Unlike it, though, the multiplexer will take your multiple video signals and combine them into a 'split-screen' format. A multiplexer is the only way to view multiple live images simultaneously on the same television, computer, etc.