2 - Copper cable

Abstract

This chapter focuses on copper cables, their types and characteristics. Two main types of copper cable are used in industrial communications—namely, coaxial cable, which is also referred to as coax and twisted-pair cable. In coaxial cable, two or more separate materials share a common central axis. Coax is used for radio frequency and data transmission. The cable is remarkably stable in terms of its electrical properties at frequencies below 4 GHz, and this makes the cable popular for cable television transmissions as well as for creating local area networks (LAN). Twisted-pair cable is widely used, inexpensive, and easy to install. Twisted-pair cable comes in two main varieties—namely, shielded (STP, FTP, and ScTP) and unshielded (UTP). It can transmit data at an acceptable rate, up to 1000 Mbps in some network architectures. All copper cable types have common components including one or more conductors to provide a medium for the signal, insulation of some sort around the conductors to help keep the signal in and interference out, and an outer sheath, or jacket, to encase the cable elements. Cables can be packaged in different ways, depending on what it is being used for and where it is located. There are different types of cable packaging, such as simplex cable, duplex cable, and multi-fiber cable. Copper cables are good for signal transfer, but they are not perfect, and signal quality can be degraded for several reasons, including attenuation, crosstalk, and impedance mismatches.