| graphic description with symbolic representation of sequential control systems|
Note 1 to entry: The symbolic representation of steps, commands, transitions and directed links is based on input and output Boolean variables and also on internal state variables and binary delay elements.
Note 2 to entry: The elements, rules and basic structures for function charts are given in IEC 60848, GRAFCET specification language for sequential function charts. Terms 351-53-09 to 351-53-16 below are to be used in this context.
Note 3 to entry: This entry was numbered 351-29-22 in IEC 60050-351:2006.