Abstract: An industrial process control system for use with complex processes having many variables to be controlled.The system includes a CRT screen on which any of a series of predetermined displays can be presented to the process operator.The displays are arranged in hierarchical fashion, from plant summary information down to detailed data for individual process loops.The operator's console includes a variable function keyboard the keys of which perform functions determined by the particular displays being presented on the CRT.The CRT display includes symbols positionally correlated with the keys and which identify the key functions for the corresponding display.The operator is enabled to control the display and the process through use of the keyboard controller with the display presentations.