Abstract

Control networks (CNs), also known as fieldbus systems, started to emerge rapidly in the early 1990s [1,2]. Back then, CNs were designed to be used in closed systems exchanging data packets on dedicated network channels. These channels included twisted pair media, power-line networks, wireless, and infrared communication. Dedicated network channels have more or less well-defined properties for bit error rates, propagation delays, and average and maximum response times, and they guarantee to maintain the packet order on the network.