lib/edge_detection.txt
author Edouard Tisserant
Fri, 19 Oct 2012 12:10:32 +0200
changeset 634 736b36a83548
parent 0 fb772792efd1
child 1094 068c28266332
permissions -rwxr-xr-x
Added double curly braces for pragma (kept single curly braces for compatibility). Added macro def and undef surrounding pragma to simplify user code. Moved useless comment from generated code back to code generator.
(* Following taken directly from the IEC 61131.3 draft standard *)

(*
 * An IEC 61131-3 IL and ST compiler.
 *
 * Based on the
 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
 *
 *)


(*
 * This is part of the library conatining the functions
 * and function blocks defined in the standard.
 *
 * Edge detection function blocks
 * ------------------------------
 *)

FUNCTION_BLOCK R_TRIG
     VAR_INPUT  CLK: BOOL; END_VAR
     VAR_OUTPUT  Q: BOOL; END_VAR
     VAR RETAIN M: BOOL; END_VAR
Q := CLK AND NOT M;
M := CLK;
END_FUNCTION_BLOCK

FUNCTION_BLOCK F_TRIG
     VAR_INPUT  CLK: BOOL; END_VAR
     VAR_OUTPUT   Q: BOOL; END_VAR
     VAR RETAIN M: BOOL; END_VAR
Q := NOT CLK AND NOT M;
M := NOT CLK;
END_FUNCTION_BLOCK