0
Does anyone use the cable test feature on EX switches? Did you even know you could do this kind of thing?
In case you didn’t, here is a bit of background and an example.
The Time Domain Reflectometer (TDR) test has been available on the EX switches for some time, but not a lot of people seem to know about it. What is TDR, I hear you ask?
A futuristic-sounding thing, what a TDR does is send a signal down a cable and measure how much (if any) is reflected by the far end. If the cable is damaged a little way along its length, the TDR test will tell you that distance to a fair level of accuracy.
In an ethernet cable, there are four pairs of conductors – eight wires in total. The operative ones are 1 & 2, and 3 & 6. The other conductors are unused but their presence in the Cat5 or Cat6 cable helps prevent cross-talk and signal attenuation. In a lab, usually cables are fairly short and easily replaced, but in a working environment, cables in floor-boxes under desks, or the structured wiring under the raised floor in an office often suffers quite Continue reading