1. Context

The definition of Industrial Systems Control refers to several facets that are often poorly dissociated. These facets are apprehended in terms of a succession of input/output (report/action) channels, where each level of decision is associated with a distinct time horizon, leading to the execution of real-time actions on machines.

Real-time control hierarchically integrates the reactive levels of operation and command. A clear distinction must be made between operation and control, by attributing to the latter, which functionally remains the closest to the process (machines and products), the ultimate power to apply requests (orders) to equipment, and to collect the information that testifies to their execution (reports). As a result, the control system has a reflex-like reactivity (forming the so-called low-level reaction loop, corresponding to level 1 according...