lib/integral_st.txt
author Andrey Skvortsov <andrej.skvortzov@gmail.com>
Sun, 14 Oct 2018 20:14:13 +0300
changeset 1073 24ef30a9bcee
parent 276 1679f514f38a
permissions -rwxr-xr-x
revert commits improved performance of some extensible Standard Functions (ADD, MUL, AND, OR, XOR)

Following commits are reverted:
mjsousa 0b275a2 improve performance of some extensible Standard Functions (ADD, MUL, AND, OR, XOR) -- increase hardcoded limit to 499
mjsousa 2228799 improve performance of some extensible Standard Functions (ADD, MUL, AND, OR, XOR) -- Add comments!!
mjsousa ce81fa6 improve performance of some extensible Standard Functions (ADD, MUL, AND, OR, XOR)"

The reason is that they cause regression in some cases (if function is
used as argument for function block, for example) and this is not
fixed for a long time.
(* 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)
 *
 *)

 FUNCTION_BLOCK INTEGRAL
   VAR_INPUT
     RUN : BOOL ;       (* 1 = integrate, 0 = hold *)
     R1 : BOOL ;        (* Overriding reset        *)
     XIN : REAL ;       (* Input variable          *)
     X0  : REAL ;       (* Initial value           *)
     CYCLE : TIME ;     (* Sampling period         *)
   END_VAR
   VAR_OUTPUT
     Q : BOOL ;         (* NOT R1                  *)
     XOUT : REAL ;      (* Integrated output       *)
   END_VAR
   Q := NOT R1 ;
   IF R1 THEN XOUT := X0 ;
   ELSIF RUN THEN XOUT := XOUT + XIN * TIME_TO_REAL(CYCLE);
   END_IF ;
 END_FUNCTION_BLOCK