Lenze PLC Designer PLC Designer (R3-1) - Manual (Page 1006)

L-force | PLC Designer
Programming Reference
1004 DMS 4.1 EN 03/2011 TD29
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Attribute No_virtual_actions
Assume function blocks, which are derived from a base function block implemented in
SFC and which are using the main SFC workflow of the base class. The actions called
therein show the same virtual behaviour as methods, that is, the base class actions
may be overloaded by specific implementations related to the derived classes.
If the action of the base class shall be prevented from being overridden, the base class
can be given the pragma {attribute 'no_virtual_actions'}.
Syntax:
{attribute 'no_virtual_actions’}
Example:
In the following example the function block POU_SFC provides the base class to be
extended by function block POU_child.
By use of the keyword SUPER the derived class POU_child calls the workflow of the
base class that is implemented in SFC.