The wiring scheme for the plug of the RJ-45 has 2 main standards T-568A and T-568B. The T-568B standard is the most commonly used standard. The wiring layout is shown with the hook/clip facing down. The plug/connector should have the pin numbers/colors match up to the color code below. When wiring a the plug, remember to keep the twist as close as possible to the plug receptacle to not degrade performance and keep compliance with Ethernet wiring standards.
Specification T-568A
| Pin # | Color | Pair # | Name |
|---|---|---|---|
| 1 | white/ green | 3 | Receive Data + |
| 2 | green | 3 | Receive Data - |
| 3 | white/ orange | 2 | Transmit Data + |
| 4 | blue | 1 | not used |
| 5 | white/ blue | 1 | not used |
| 6 | orange | 2 | Transmit Data - |
| 7 | white/ brown | 4 | not used |
| 8 | brown | 4 | not used |
Specification T-568B (most commonly used wiring standard)
| Pin # | Color | Pair # | Name |
|---|---|---|---|
| 1 | white/ orange | 2 | Transmit Data + |
| 2 | orange | 2 | Transmit Data - |
| 3 | white/ green | 3 | Receive Data + |
| 4 | blue | 1 | not used |
| 5 | white/ blue | 1 | not used |
| 6 | green | 3 | Receive Data - |
| 7 | white/ brown | 4 | not used |
| 8 | brown | 4 | not used |
Crossover cable
Some applications may require a crossover cable but most modern hardware will auto swtch/crossover the pins if needed. The most common use of a crossover cable occurs in wiring together two 2 computers together with a single cable and no devices inbetween. A crossover cable will Transmit and Receive Data, Pins 1 and 3 are crossed over, and Pins 2 and 6 are crossed over. To make a crossover cable, simply wire one side according to specification T-568B, and the other side to T-568A.
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