Diagrams have long been used to define the requirements and the details of Process Automation systems.
Process Flow Diagrams are used early in the development of a plant and these can show the most important control requirements
Piping and Instrument Diagrams are produced as the plant design develops and these show more of the control - but never enough
Loop Diagrams such as SAMA provide even more detail for control loops and logic. They go back at least 30 years, probably more. They are now often known as function block diagrams.
Grafcet / Sequential Function charts are diagrams for defining state oriented sequential control scheme.
Control System Graphic displays are like little P&ID's but focused on operation. These days they are mostly shown on DCS and SCADA screens but originally they were done with hard wired panels.
Procedure Function Charts define S88 Recipe procedures
For more on P&ID's and PFD's see the University of Michigan Chemical Engineering Controls Wiki.
For another more general list, see RoyMech's Process Diagrams and Drawings
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