This standard applies to the preparation of descriptions of the function and behaviour of control systems by establishing an
implementation-independent graphical representation. It includes the symbols required as well as rules for their use.
This standard has been prepared with a view to electrotechnical applications (especially industrial ones, including electric power generation and distribution), but as it provides a general process orientated way of describing control functions, independent of their technological implementation, no field of application is explicitly excluded. It may also be applied to non-electrical systems (for example pneumatic, hydraulic or mechanical) or to parts of systems.
The described method of representation should serve as a communication tool between different parties often representing different technological disciplines, involved in the engineering and use of control systems.
NOTE - The method of representation described can be considered as an industrial application of "Petri nets" used for the study of the co-ordination of asynchronous events. Compared to "Petri nets", it offers the possibility to start with an overall description of a control system and may, via progressive levels of description, proceed to a description in which all the details of the system are revealed.
A mathematical description of the function chart is given in Annex A.