KVM Extenders and Switches
From Fozzee.net
Contents |
KVM Switching
KVM Switches come in 2 main varieties: Passive and Active. Passive switches are really nothing more than a box that moves the wires from one keyboard, mouse and monitor between multiple systems. This sort of switch is not terribly useful, as, if it's swiched while systems are powered on, it can cause weirdness.
For our purposes, most KVM switches are powered, known as "Active" KVM switches. Most of the time, these switches emulate a keyboard and mouse on systems, even when you don't have them selected. Some switches (more $$$) do this better than others, so thats something to watch out for. This sort of switch often also can't select channels that dont have a computer on them. If you intend on using this as a video-only switch, you'll need to find a way to put +5v on the keyboard port. I like using a USB -> PS2 adaptor.
KVM Extension
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Other types of Extension
The short of it (no pun intended) is that just about any sort of signal can be extended over twisted pair cable. The one thing to keep in mind is that noise is best managed by keeping data twisted with ground. Also, in case you're running power (as in a USB Extender), use as many wires as you can spare (be that 1 pair, 2 pair or 3 pair) for the +5v, to make sure that it's most of 5 volts when it gets to the end. Otherwise, your device might not power up completely, and can cause errors when detecting new hardware, among other problems.
