Analog Signals and Analog I/O
Dag H. Hanssen · 2015
This chapter gives a brief introduction to the processing of analog signals. It looks at various standard formats for signals in process engineering, how analog signals are converted to discrete (digital) signals, and vice-versa in a PLC. The chapter also looks briefly at the processing of discrete and analog signals, considerations involved in cabling, and a bit about connecting analog equipment. It reviews the three most important types of temperature sensors used in industry: thermocouples, RTD (PT100 et al.), and thermistors. Among other types, one can mention radiation pyrometers. The chapter ends with an example of an analog output module and its specifications.