Advances in the design of integrated circuits and embedded systems, tools availability, and falling fabri-
cation costs of semiconductor devices and systems (system-on-chip. SoC] have allowed for an infusion
of intelligence. such as sensors and actuators into field devices. The controllers used with these devices
typically provide on-chip signal conversion, data and signal processing, and communication functions.
The increased functionality and processing capabilities Of controllers have been largely instrumental in
the emergence of at widespread trend for the networking of field devices around specialized networks.
frequently referred to as field area networks [I].