Wire sequence of RJ45 plug
568A standard
| Pin order | Direct connection signal of medium | Colour |
|---|---|---|
| 1 | TX+(transmission) | White Green |
| 2 | TX-(transmission) | Green |
| 3 | RX+(receive) | White Orange |
| 4 | Not used | Blue |
| 5 | Not used | White Blue |
| 6 | RX-(receive) | Orange |
| 7 | Not used | White Brown |
| 8 | Not used | Brown |
568B标准
| Pin order | Direct connection signal of medium | Colour |
|---|---|---|
| 1 | TX+(transmission) | White Orange |
| 2 | TX-(transmission) | Orange |
| 3 | RX+(receive) | White Green |
| 4 | Not used | Blue |
| 5 | Not used | White Blue |
| 6 | RX-(receive) | Green |
| 7 | Not used | White Brown |
| 8 | Not used | Brown |
5 colors. Twisted pair can have anti-interference effect!!!!! Among the 8 cables of the network cable, 1236 is used for transmitting digital signals, which is used for data transmission in our network. 45 is used for analog signals, which is used for telephone pulse signal transmission. 78 is used for power supply of IP phones, which of course requires POE support. In fact, when operating on a 100M network, usually all eight cores are used because 100M network transmission requires high line requirements, not only 1 3 2 6, otherwise the network operation will be unstable.
Understand the principles and practices of Category 5 twisted pair cables
一、Firstly, let's have a specific understanding of what twisted pair is
1、Twisted pair cable: As a transmission medium, it is composed of two thin copper wires wrapped in insulating material and wound together in a certain ratio.
The relevant images for this topic are as follows：
The picture shows Category 5 twisted pair cables, consisting of four pairs of intertwined wires, totaling eight wires.
2、Why twist the two wires in pairs?
Because this mutual entanglement changes the original electronic characteristics of the cable. This not only reduces its own crosstalk, but also maximizes the prevention of interference from signals on other cables on this pair of cables.
3、Classification of twisted pair cables:
1）Twisted pair cables can be divided into 2 pairs, 4 pairs, and 25 pairs based on their number of twisted pairs. (For example, 2 pairs are used for telephone, 4 pairs are used for network transmission, and 25 pairs are used for telecommunication large pair cables)
2）According to whether there is a shielding layer, it can be divided into two categories: shielded twisted pair (STP) and unshielded twisted pair (UTP).
3）According to frequency and signal-to-noise ratio, it can be divided into 3 categories, 4 categories, 5 categories, and over 5 categories. Nowadays, many places have already used Category 6 or even Category 7 wires. Used in computer network communication with at least three categories. Below are various line descriptions:
Class I: mainly used for transmitting voice (Class I standards were mainly used for telephone cables before the early 1980s), not for data transmission.
Category 2: Transmission frequency is 1MHz, used for voice transmission and data transmission with a maximum transmission rate of 4Mbps, commonly found in old token networks that use the 4Mbps standard token passing protocol.."
Category 3: Refers to cables currently specified in ANSI and EIA/TIA568 standards.