rs-485 over cat6, is there a standard for which colors are used for what?

[signal15]

Like the subject says. I'm just starting some wiring, and I want to know if you are doing rs-485 over cat-6, is there a standard for which wires are used for power and data A/B?

 

[electron]

Not as far as I know. Just make sure you document everything, and use the same colors for the same wires everywhere, and you should be fine.

 

[gatchel]

I also have not seen an standard for 485 on CAT 5/6 cable. There are pair numbers though:

Pair 1-Blue
Pair 2-Orange
Pair 3-Green
Pair 4-Brown

I usually use them in that order.

 

[signal15]

Doh, I'm a dummy. I happened to actually look at the instructions that came with the ELK Data Hub, and it has them in there:

This holds true for both T568A and T568B wiring, even though the instructions say T568A (Orange and Green are swapped on T568B, which doesn't make a difference in this case):
Brn - Positive
Wht/Brn - Negative
Twist green and orange together - Data A
Twist wht/grn and wht/orange together - Data B
Blue - Not used

The reason you twist them together is that one of them is used for data return to the hub for the next port.