Toner Probe vs Loopback Plug

[kuroteckie]

Good afternoon Techies,

I am currently studying for my A+ exam and I know that I will also need this knowledge while I am out on the field. I don't quite understand the functionality of a toner probe & loopback plug. I know they are both used to test the connections of wires and wall jacks but I am confused on how they do so. I have researched online about what they both do but it isn't quite as clear as I'd like it to be. Can anyone explain? Thank you in advance

 

[nigelivey]

It's basically used to identify either a single cable or in telephony cores within a cable. One end of the cable you have a tone generator you would then use the probe the other end where you need to identify that one cable in a loom of many, think of as a metal detector that emits a sound the closer to metal you get. The loop back plug I presume is part of your test kit. You would install on one end of the cable then use your tester the other end. On simple testers it will identify correct pin outs and also shorts. More advanced testers will give you cable length and various other results if instead of using the plug you have the cable patched into another device (port information such as vlan ID, DHCP, IP and gateway).