Cat5 Cable strand uses - 4 conductors for data and 4 for PoE.

[Cilbuper]

I've seen that in some ethernet cables there are really only 4 strands in use if PoE is not being utilized. Would it be possible to use one cable for 2 separate connections, meaning use the 4 PoE strands for another connection so that 2 connections could be run over one wire.? (The more I look, this might only be possible with 10/100mbit). The only question I have is that each colored strand has a different twist rate from 52, 56, 65 and 72 twists per meter, so IDK if that would mess up some things with data transfer.

The reason I ask is because this would be great for running cat5 to low data flow devices like cameras that don't need all 4 TP's (unless it utilizes PoE).

The above image is the closest diagram that I have found that shows how the different strands are used, although this is mainly for PoE so I'm not sure if it is the same for non PoE utilized cables.

Does anyone know how to make the most out of these cables if not using PoE?

 

[Red Squirrel]

You probably could if you build some kind of splitter at both ends. But you wont get gigabit.

Personally I'd just run two cat6 runs from the patch panel and be done with it.

In a situation where you're REALLY stuck, I imagine it would be possible to multiplex multiple signals on a same cable. Though you would need two very accurate clock crystals at both ends or a separate clock signal. Easier to just run 2 cables.

 

[JackMDS]

A good use if Not using POE is not to use anything but Network connection.

The whole idea of these cable is to protect the Network signal from electrical noise not to introduce more noise with whatever else you will "dump" on it.

 

[azazel1024]

I mean, if you REALLY wanted to, you could break the cable out to two connections on either end, but I don't know that it would really save you a lot, and it might lead to interference/data corruption issues. 100base-TX and 1000base-T (and 10gigabase-T) all are likely taking something in to account with induction from neighboring pairs, as even with the twisting, there will be some amount of induction.

Granted, the level of induction might be so low that there isn't anything taken in to account for voltage levels on each wire to determined a 0 or a 1.

At any rate, I just don't see how you are really saving much of anything. Switches are so damned cheap that you can get a 5 port 10/100 switch for $10 (maybe less in places) if you need to break out to more connections. Want to use all that capacity with a bunch of connections? Get a $15 gigabit switch and connect it to 4 10/100 devices then.

Or run more wires. Wire is fairly cheap.

 

[gsaldivar]

Yes. 10/100 Ethernet requires only two pairs (4 wires) leaving you with two unused pairs in a standard Cat-5/Cat-6 cable. If you don't want to manually separate the pairs, you can pick up some adapters that will provide you with two Ethernet connections. You will need one adapter for each end of your cable (1M/2F or 2M/1F, depending on your application):

http://www.monoprice.com/Product?c_id=105&cp_id=10513&cs_id=1051304&p_id=1107&seq=1&format=2

http://www.monoprice.com/Product?c_id=105&cp_id=10513&cs_id=1051304&p_id=1106&seq=1&format=2

Keep in mind that these adapters will not work with Gigabit Ethernet, as all cable pairs are used at that speed.

Good luck!

 

[gsaldivar]

each colored strand has a different twist rate from 52, 56, 65 and 72 twists per meter, so IDK if that would mess up some things with data transfer.

The reason for this is to prevent crosstalk interference between the 4 cable pairs. You shouldn't have any issues at 10/100 speeds if you stick to standard Ethernet distance limits.

Good luck.

 

[imagoon]

I hate when I see these things. They are a short cut that normally is evidence that many other short cuts are likely present. They also tend to "save" money on cable but pay out the butt to get power to the cameras etc which then often is a net loss.

 

[Ichinisan]

I've done 2 through 1 in a pinch. I'm told that it's not advisable because crosstalk interference can be an issue. Regardless, it's probably better than WiFi.