SFC

Sequential Function Chart

A graphical programming aid for the programming of PLC's (Programmable Logic Controllers). Part of IEC 1131. An SFC consists of Steps, Actions and Transitions. A step is a unit of programming logic that performs a control task. Actions are the individual aspects of that task. Transitions are the mechanisms used to move from one task to another. Control logic for each Step, Action and Transition is programmed in one of the other IEC 1131 languages such as a LD or ST.