Twisted pair cable

Twin-fluid atomizer Twisted pair cable Twitchell splitting Twitchell s reagents Two-film theory... 

Eig. 1. Cable designs (a) coaxial cable (b) twisted pair cable can be unshielded, as in regular telephone wiring, or shielded (as shown here) with braiding or... 

The twists of twisted pair cable act as a shield against radio frequency interference (REI), and electromagnetic interference (EMI), and against the cross talk interference that a wire exerts on nearby wires the more twist the less interference. Telephone wires can use large numbers of pairs. In most cases the pairs are not shielded with braiding or foil, as shown in Eigure lb for data communication wire. Data communication wires work at very high... 

The speed of information transfer can be increased by switching from twisted pair cables to coaxial or fiber optics, however, these types of cables add to the installation costs. In the future, communications between sensors and multiplex boxes and the rest of the system may use a combination of technologies including traditional means such as twisted wire and coaxial and non-traditional methods such as infrared or radio wave. 

Clearly, such interference can be reduced by increasing the distance between the source and the measurement circuit—mutual inductance and capacitance both being inversely proportional to the distance. Inductive coupling can also be much reduced by the use of twisted pair cable (Fig. 6.65). If adjacent loops in the circuit have the same area (e.g. loops 1 and 2) and are coupled with the same magnetic field, then the induced voltages between points A and B and between B and C will cancel each other out, and this will be repeated along the whole section of twisted pairs. 

Twisted-pair cable Coaxial cable Fiberoptic... 

Coaxial cable is less sensitive to noise and is suited for higher transmission speeds than twisted-pair cable. Baseband techniques (serial bit-by-bit transmission) as well as (frequency modulated) broadband techniques are possible. Types of possible communication techniques in coaxial cables are listed in Table 9.2. 

Unshielded twisted pair cable (UTP) offers many advantages over the ThickWire and Thin Coax media. Because ThickWire and Thin Coax are coaxial cables, they are relatively expensive and require some care during installation. UTP is similar to, if not the same as, the telephone cable that may already be installed and available for network use in your building. 

We usually break twisted-pair cabling into two types unshielded twisted-pair (UTP) and shielded twisted-pair (STP). UTP is simply twisted-pair cabling that is unshielded. STP is the same as UTP except that STP has a braided foil shield around the twisted wires (to decrease electrical interference). 

A. Of the choices listed above, twisted-pair cabling is generally considered the easiest to install due to the fact that it is lighter than coaxial and doesn t require a lot of special tools or knowledge like fiber-optic cable. 

STP (shieid twisted-pair) Cabling that has a braided foil shield around the twisted pairs of wire to decrease electrical interference. 

FIG. 4—Soil sensor for electrochemical measurements, made of two reference electrodes, two working electrodes, and three counter-electrodes, all connected to their own shielded twisted pair cable. At the terminal box, they can be accessed in various combinations depending on the tests required. It also has two platinized titanium electrodes equally spaced with the reference electrodes to allow for the measurement of the average soil resistivity by the Wenner four-electrode metlrad. The two working electrodes can be designed to represent the different conditions of the structure being monitored. 

Foamed fluoroplastics have been used in coaxial cables since the 1960s, but they are receiving increased interest for twisted-pair applications since the dielectric performance of all solids can be improved by the uniform addition of voids. Current efforts focus on smaller and more uniform voids that can be incorporated into thin-walled products such as micro coaxial cables and twisted pair cables. The use of advanced foamed perfluoroplastic resins provides the cable designer with options for improving cable performance and/or reducing cable weight [14,15]. 

The physical medium used for fieldbuses is quite simple - it can be a shielded twisted pair cable or coaxial cable. The important characteristics tend to be in the data structures and protocols used, and these generally conform to published standards. 

Fig. 2 Twisted-pair cable https //commons.wikimedia.org/wiki/File Twisted pair. svg...

There has been a drawn-out discussion in the automotive industry about whether to make STP cable or coaxial cable standard. Currently, both shielded and unshielded twisted-pair cables as well as coaxial cables are in use. The latest chipsets, however, show a trend towards normal coaxial cable [2, 3]. 

Eight TTL-compatible data lines. Each has its own signal ground return for use with twisted pair cables. 

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