Gary Eckert

Communication Networks, Buses Tie Controls to Real World

As controls and automation become more distributed and integrated, industrial communication networks and buses are becoming more crucial because they link controls with real world, in-the-trench, manufacturing processes. However, due to growing choices of networks, protocols, buses, and node connections, it is helpful to understand the basic aspects of each network or bus before picking an overall architecture. Physical topologies include linear buses (with drops), and daisy-chained, ring (where all nodes are connected in a physical ring), star, and mixed types. Each has its own advantages and drawbacks. Bus arbitration schemes include master-slave and peer-to-peer (CSMA or collision sense/multi-access, and token-passing).