lib/edge_detection.txt
author Andrey Skvortsov <andrej.skvortzov@gmail.com>
Fri, 06 May 2016 11:38:35 +0300
changeset 1007 afb3974f8fb3
parent 0 fb772792efd1
child 1094 068c28266332
permissions -rwxr-xr-x
fix warning about overflow if matiec is running on 64-bit platform,
but the generated C code will cross-compiled for 32-bit platform

For example:
./build/config.c:29:39: error: large integer implicitly truncated to unsigned type [-Werror=overflow]
unsigned long greatest_tick_count__ = 18446744073709551611UL; /*tick*/
^
compilation terminated due to -Wfatal-errors.
cc1: all warnings being treated as errors
(* 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