Remove RETAIN qualifier for F_TRIG and R_TRIG 'M' variable. This is not following standard, and implicitely consumes a lot of RETAIN memory. User can explicitely qualify R_TRIG of F_TRIG instance as RETAIN if needed.
(* 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 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 M: BOOL; END_VAR
Q := NOT CLK AND NOT M;
M := NOT CLK;
END_FUNCTION_BLOCK