17 – Radio and wireless communications overview

Publisher Summary This chapter focuses on radio and wireless communication systems and their main features. Radio telemetry systems are used significantly by a number of industrial protocols. Radio is often chosen in preference to using landlines for a number of reasons: costs of cable can far exceed that of radio telemetry systems; radio systems can be installed faster than landline systems; radio equipment is very portable and can be easily moved; radio can be used to transmit the data in any format required by the user; reasonably high data rates can be achieved compared to some landline applications; and radio can be used as a backup for landlines. A radio link consists of several components, namely, antennas, transmitters, receivers, antenna support structures, cabling, and interface equipment. Radio modems are suitable for replacing wire lines to remote sites or as a backup to wire or fiber optic circuits and are designed to ensure that computers and programmable logic controller (PLCs) can communicate transparently over a radio link without any specific modifications required.