Structured Wiring Crib Sheet

6 Position Connector Pin Numbering

8 position connectors are numbered in the same way.

UTP Wiring Usage

FCC 8P8C connector pins1 1 2 3 4 5 6 7 8
T568A White/Green Green White/Orange Blue White/Blue Orange White/Brown Brown
--- 3 ---   --- 1 ---   --- 4 ---
  --------- 2 ---------  
T568B White/Orange Orange White/Green Blue White/Blue Green White/Brown Brown
- 2 -   - 1 -   - 4 -
  ---- 3 ----  
Ethernet2 T+ T- R+ n/c n/c R- n/c n/c
PoE3 802.3 Alternative A Polarity 1 Polarity 2   Polarity 2  
802.3 Alternative B     Polarity 1 (+?)   Polarity 2 (-?)
Passive     DC +   DC -
DMX-512 Data 1+ Data 1- Data 2+   Data 2- Signal Common (0 V) for Data 1 Signal Common (0 V) for Data 2
UK Telephone   PABX Earth Bell n/c B A n/c n/c n/c
Socket BT4 BT3 BT1 BT2 BT5 BT6 - -
Plug BS3 BS4 BS6 BS5 BS2 BS1 - -
Hobbyboard 1-wire 0V +5V 0V 1-wire data 1-wire ground   +12V unreg 0V
DS9490R#4
(6P6C)
  VDD GND 1-Wire 1-Wire Gnd !SUSO n/c  
  1 2 3 4 5 6  

1) FCC 8P8C Modular Connectors are often, somewhat incorrectly, called RJ45 connectors.

2) Some flavours of gigabit Ethernet use all eight pins.

3) Power over Ethernet

4) Dallas/Maxim 1-wire adaptor.

British Telecom Standard Wiring

BT (socket) pin number 1 2 3 4 5 6
BS (plug) pin number 6 5 4 3 2 1
Function n/c B (-50V) Bell PABX Earth A (0V) n/c
In-house (ext/ext) colours4 Green Blue Orange White/Orange White/Blue White/Green
Possible drop colours5 n/c Orange n/c n/c White n/c

4) In-house refers to wiring between the master socket and extension sockets and between extension sockets.

5) Drop refers to the external wires into the master socket, from the exchange. Colours often vary, it seems; these are just the most common.