Product : ISaGRAF V3.3
Date : 27-July-1998
File : FC_SFC.Comparison between FC and SFC.htm
Subject : Comparison between FC and SFC
Keywords: Flow Chart - SFC - Sequential Function Chart
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Here below is a comparison between FC and SFC dynamic behavior:
FC |
SFC |
1- at first cycle |
Begin' is 'activated No code in 'begin' action can be executed |
Initial step(s)is activated Code of P1 actions of the initial step(s) is executed once. Code of N actions of the initial step(s) is executed. |
2- at next cycle |
All possible actions and tests are performed until: - a FC sub-program is called - a loop is met= program tries to execute an action that has already been executed in 2nd cycle
|
If condition in transition(s) just after active
steps is FALSE: code of N actions of active step is executed again.
If that condition is TRUE, the active step is deactivated and steps immediately following are activated: - there is the active step de-activation, i.e. code of P0 actions is execute - in new active step(s) code of P1 actions is executed - in new active step(s) code of N actions is executed |
3- sub-program call |
Father program code is not executed until child
program execution is ended.
One FC program can have only ONE of its children being executed at once. |
Father program code is executed in the same time
child program code is executed.
Many child programs can be executed in parrallel. Child program execution can be interupted by father program. |
Below is a vocabulary comparison between FC and SFC components
FC SFC
- actions - steps
- conditions - transistions
- sub-program - child
Please read ISaGRAF 3.3x workbench readme file (About flow chart)
and on-line help (language reference section) for more information
on Flow Chart and SFC languages.
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