Plant constructors are increasingly being confronted with the demand for greater flexibility while having to cope with more intense time and cost pressures. Decentralized automation systems go a long way to meet these new requirements. Thus, for example, decentralized , intelligent compact controllers can be used to turn the components of modulary designed installations into autonomus units which communicate with a CPU via high-speed serial data bus. These communications may range from simple access to input and output channels to the transfer of entire user programmes.
