Twisted Pair Cable is used in telecommunications, messaging and computer engineering , in which the wires are in pairs are twisted. Pairs can have varying degrees of twist and different directions of rotation in a cable. Twisted pair cables offer better protection against external magnetic fields and electrostatic influences. In the guide on Connecting Two Computers With USB Port over Ethernet, we mentioned about Twisted Pair Cable and here is the theoretical part.
Twisted Pair Cable : Basics
An electrically conductive shield often made of aluminum foil and or metal mesh, which is usually made of copper also offers protection against external interfering electromagnetic fields. Twisted pair cable without this screen are as Unshielded Twisted Pair (UTP). Twisted Pair Cable with aluminum foil as a shield bears the letters FTP (Foiled Twisted Pair). Twisted Pair Cable with a braided copper shield, bears the letters STP (Shielded Twisted Pair). There are also cables, in which the pairs are shielded against each other, they are referred to, for example, with S / STP (Shielded Twisted Pair) or S / FTP.
Twisted-pair cable can be used for a long time for signal and data transmission in computer technology, initially used for the parallel port of the printer. Today appropriate cable for all types of signal transmission can be used, including the network technology like Ethernet cables or for the structured cabling or in the fieldbus.
Twisted Pair Cable : Basic Technical Part
Twisted pair cable contain pairs of two twisted together (english twisted) pairs (English pair) of individual wires.
Core is a plastic-insulated copper conductors works as rigid wire with a standard diameter of 0.4 mm or 0.6 mm. With flexible patch cables as wire has a standard cross-section of 0.27 to 0.50 mm ².
Cable jacket surrounds the core. It consists mostly of plastic mesh and smooth shell over it. Material used is often PVC or halogen-free materials such as PE or aramid .
Plastic thread (for example, nylon ) between the overall shield and jacket can be removed with a simple way by holding the thread with a pair of pliers and pulling it back at an acute angle.
When using unshielded cables, the isolation transformers in the signal path is placed between network devices with no ground connection. The shield favors the electromagnetic compatibility (EMC) and privacy and no interaction with other devices.
In differential and symmetrical signal transmission, a ground or earth connection is not required unless a common noise must be suppressed. An additional sheath disrupts the protective mechanism of twisting, it offers an additional protection. The outer sheath is designed to improve protection and suppresses the emissions.