Distributed process control concept spreads
Chemical & Engineering News · 1979
The profusion of computing hardware and programing languages in process control isn't diminishing. But an organizational concept in industrial control being evolved by control engineers and system designers is bringing more order. The concept is based on recognition of two spectra of functions that must be accommodated simultaneously by a control system: hierarchical functions and distributed functions. Hierarchical functions are those involved in the instrument and computer pecking order—from, say, data acquisition and hardware actuation at the lowest level through control loop regulation and unit optimization to management information systems at the highest level. Distributed functions refer to the proper placement of the control functions at any given hierarchical level within the equipment areas, process units, plants, or facilities. In summarizing the general industrial control picture for the recent 1979 Joint Automatic Control Conference in Denver, D. Grant Fisher ...