"Intelligent sensors and fieldbus" is a course describing systems for industrial automation for Industry 4.0. A special attention is paid to smart sensors and fieldbuses. It addresses the context of industrial automation at the field level, analyzing factory automation, process, intrinsic safety, with a focus on architectures based on field bus, wired and wireless. In particular, the path that led from the fieldbuses to Real-Time Ethernet solutions and wireless technologies is discussed. Particular attention is given to real-time applications for industry, with reference to the time synchronization, and networks for smart grid and smart metering, with a brief outline of the powerline technologies.