ControlDraw Presentation
This web was generated automatically from a sample ControlDraw model.
Move the mouse over the diagram area - you can click on the objects that have numbers by them to go to the detailed diagram for the object. It is a bit like using ControlDraw (but that is much more powerful!)
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List of Diagrams
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001 - Contents
002 - Symbols
003 - Connections
004 - Diagram types
005 - GRAFCET (SFC) DIAGRAM
006 - SAMA Loop
007 - Logic diagram
008 - Process Flow (P & I D)
009 - State transition
010 - Procedure Flowchart
011 - S88 Procedure Flowchart
012 - Flowchart
013 - System diagram
014 - On Off Valve
015 - Ladder diagram
016 - Drawing Trees
017 - Database Functions
018 - Matrix Functions
019 - Gamp Life Cycle
020 - Feedback Control Loop
021 - PID Control Loop
022 - Connections
023 - Documentation for the Life Cycle
024 - The P&ID
025 - S88 Models
026 - Site Recipes
027 - Polymorphic diagrams
028 - Multi model projects
029 - Large distributed projects
030 - GAMP 3 Life Cycle
031 - Model Structure
032 - RS to Code Data Flow
033 - System Development
034 - ControlDraw with CAD
035 - System Development Structure
036 - Design your graphics
037 - Version Controls
038 - Process Eng Diagram Flow
039 - PFD02
040 - MES Model

5 - Grafcet (SFC) diagram (Phase)

ControlDraw provides quick ways to draw SFC's and to place them and their steps and transitions in context in an automation model.

How an SFC works:
The dynamic
behaviour was first written as five evolution rules, mentioned in IEC 848 standard :

  • Rule 1 : Initial situation
  • The initial situation is characterised by the initial steps which are by definition in the active state at the beginning of the operation. There shall be at least one initial step.
  • Rule 2 : R2, Clearing of a transition
  • A transition is either enabled or disabled. It is said to be enabled when all immediately preceding steps linked to its corresponding transition symbol are active, otherwise it is disabled. A transition cannot be cleared unless: it is enabled, and its associated transition condition is true.
  • Rule 3 : R3, Evolution of active steps
  • The clearing of a transition simultaneously leads to the active state of the immediately following step(s) and to the inactive state of the immediately preceding step(s).
  • Rule 4 : R4, Simultaneous clearing of transitions
  • All simultaneous cleared transitions are simultaneously cleared.
  • Rule 5 : R5, Simultaneous activation and desactivation of a step
  • · If during operation, a step is simultaneously activated and deactivated, priority is given to the activation.



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