A Lighting Control & Design bus that has been terminated with the 1-4 block connections do not use the 568B standard in the cat-5 cable and in most cases only use 3 pair from the cat-5 cable. You will typically run into 2 types of connection a single cable into a 1-4 block at a panel or end of line and 2 cables into a single 1-4 block at switches and other devices.
In each case the brown pair is not used; the blue pair is +12v; the orange pair is data and the green pair is ground.
To add a new device with RJ-45 terminals to a 1-4 block system you can use a Bus Checker card, a 1-4 Block to RJ-45 Converter or attach an RJ-45 terminal to the old cable using the correct color pattern NOT 568B.
To determine what pattern you need you need to understand how LC&D bus works.
With a bus using the 568B standard the following is what the colors conduct
With a bus using the 1-4 Block the following is what the colors conduct
To convert a 1-4 Block Bus:
- Cut the brown pair off.
- Green/White to #1
- Green to #2
- #3 Empty
- Orange to #4
- Orange/White to #5
- #6 Empty
- Blue/White to #7
- Blue to #8
The brown pair is cut off
The cable is now ready for a RJ-45 system.