<< Click to Display Table of Contents >> Navigation:  »No topics above this level« Function blocks (IEC ST)

mapp Services V5.16

The definition of a function block includes its implementation. A pure declaration without implementation is used to map external function blocks.

Example

FUNCTION_BLOCK RS // RS latch

  VAR_INPUT

       SET : BOOL; // Sets output Q

       RESET : BOOL; // Resets output Q (priority)

  END_VAR

  VAR_OUTPUT

       Q : BOOL; // Output value

  END_VAR

   Q := NOT RESET AND (SET OR Q);

END_FUNCTION_BLOCK

The scope of declared function blocks is determined according to the file extension and the most recent #pragma SCOPE.

Topics in this section:

•Calling function blocks