Crimping tool twisted pair connection

The standard connection of the twisted pair is not strictly specified, but is made to keep the symmetry of the cable joint as much as possible, so that the interference between the cables in the joint can be offset to the minimum. At the same time, the differential signal values ​​of the external interference can be made equal as much as possible so that the anti-interference circuit can perform the subtraction operation to eliminate it.

Therefore, when we usually make a network cable, if it is not made according to the standard, although the line can be connected sometimes, the interference between the pairs inside the line cannot be effectively eliminated, so that the signal transmission error rate increases, eventually leading to network performance degradation. .

In fact, the cable connection we used in this article is the EIA/TIA 568B standard, and there is also a standard for EIA/TIA 568A, which simply swaps the orange line pair and the green line pair in the figure (that is, green and white). -1, Green-2, Orange-3, Lan-4, Lanbai-5, Orange-6, Brown-7, Brown-8), the layout of the cable joint is still symmetrical. Comparing the above figure with the standard connection diagram, it can be found that the two actually exchange the green line pair and the orange line pair. The careful person will find that it just happens to be the EIA/TIA 568A standard, so the production of the direct twisted pair is said. The standard connection is to press EIA/TIA 568A at one end and EIA/TIA 568B to connect the other end. Both ends meet international standards, which is the benefit of doing the standard line.

What is the difference between Category 3, Category 5, and Category 5?
First of all, why use twisted pairs instead of parallel lines? Is parallel lines easier to produce?

This is because the high-frequency signal of >10MHz passes through the network line. At this time, the insulated wire between the wires is equivalent to a dielectric plate, and the capacitance formed by the wire and the wire form a bypass attenuation effect on the high-frequency signal (signal phase) It is delayed, because the signal frequency is high and cannot be ignored, so it is impossible to transmit high-frequency network signals by parallel lines.

But if we twist the parallel pairs, we will form a series inductor at the same time as the capacitor is formed. The sketch is as follows:
According to the knowledge of electronic circuits, the function of the inductor is just opposite to the capacitance. It makes the signal phase lead. As long as the winding of the wire is adjusted, the inductance and capacitance formed by the pair can be exactly offset, and the length of the pair increases. The effects are equally increased, and ideally the signal can be transmitted over twisted pairs without attenuation.
From this we can know that although the 3, 5 and 5 types of lines on the market are basically similar in appearance, there are certainly some differences in the interior: First, the insulation material of the signal line is different, the better the line, it The lower the dielectric constant should be, so that the smaller the capacitance is formed, and the second is that the winding of the pair may be different (determined by the dielectric constant of the insulating material).