lib/timer.txt
author Edouard Tisserant
Fri, 19 Oct 2012 12:10:32 +0200
changeset 634 736b36a83548
parent 392 9b88b8b6bccd
child 885 b2604fc6d25c
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.
(*
 *  This file is part of matiec - a compiler for the programming
 *  languages defined in IEC 61131-3
 *
 *  Copyright (C) 2011  Mario de Sousa (msousa@fe.up.pt)
 *
 * See COPYING and COPYING.LESSER files for copyright details.
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 * USA
 *
 * This code is made available on the understanding that it will not be
 * used in safety-critical situations without a full and competent review.
 *)

(*
 * An IEC 61131-3 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.
 *
 * Timer Function Blocks
 * ---------------------
 *
 * NOTE: The timing diagrams in the comments (except the state variable) 
 *       were taken from the IEC 61131-3 standard.
 *)



(****************************************************************

                  TP - pulse timing - state machine


            +--------+     ++ ++   +--------+
       IN   |        |     || ||   |        |
          --+        +-----++-++---+        +---------
            t0       t1    t2 t3    t4       t5
            +----+         +----+  +----+
       Q    |    |         |    |  |    |
          --+    +---------+    +--+    +-------------
            t0   t0+PT    t2 t2+PT t4  t4+PT
         PT      +---+          +       +---+
          :     /    |         /|      /    |
       ET :    /     |        / |     /     |
          :   /      |       /  |    /      |
          :  /       |      /   |   /       |
          0-+        +-----+    +--+        +---------
            t0       t1    t2      t4       t5


        2        +---+          +       +---+
STATE   1   +----+   |     +----|  +----+   | 
        0 --+        +-----+    +--+        +---------


****************************************************************)

FUNCTION_BLOCK TP
  VAR_INPUT
    IN : BOOL;  (* first input parameter *)
    PT : TIME;  (* second input parameter *)
  END_VAR
  VAR_OUTPUT
    Q : BOOL := FALSE;  (* first output parameter *)
    ET : TIME := T#0s;  (* second output parameter *)
  END_VAR

  VAR
    STATE : SINT := 0;  (* internal state: 0-reset, 1-counting, 2-set *)
    PREV_IN : BOOL := FALSE;
    CURRENT_TIME, START_TIME : TIME;
  END_VAR

  {__SET_VAR(data__->,CURRENT_TIME,__CURRENT_TIME)}

  IF ((STATE = 0) AND NOT(PREV_IN) AND IN)   (* found rising edge on IN *)
  THEN
    (* start timer... *)
    STATE := 1;
    Q := TRUE;
    START_TIME := CURRENT_TIME;

  ELSIF (STATE = 1)
  THEN
    IF ((START_TIME + PT) <= CURRENT_TIME)
    THEN
      STATE := 2;
      Q := FALSE;
      ET := PT;
    ELSE
      ET := CURRENT_TIME - START_TIME;
    END_IF;
  END_IF;

  IF ((STATE = 2) AND NOT(IN))
  THEN
    ET := T#0s;
    STATE := 0;
  END_IF;


  PREV_IN := IN;

END_FUNCTION_BLOCK




(****************************************************************

             TON - On-delay timing - state machine


            +--------+        +---+   +--------+
       IN   |        |        |   |   |        |
          --+        +--------+   +---+        +-------------
            t0       t1       t2  t3  t4       t5
                 +---+                     +---+
       Q         |   |                     |   |
          -------+   +---------------------+   +-------------
              t0+PT  t1                t4+PT   t5
         PT      +---+                     +---+
          :     /    |            +       /    |
       ET :    /     |           /|      /     |
          :   /      |          / |     /      |
          :  /       |         /  |    /       |
          0-+        +--------+   +---+        +-------------
            t0       t1       t2  t3  t4       t5


        2        +---+                     +---+
STATE   1   +----+   |        +---+   +----+   |
        0 --+        +--------+   +---+        +------


****************************************************************)


FUNCTION_BLOCK TON
  VAR_INPUT
    IN : BOOL;  (* first input parameter *)
    PT : TIME;  (* second input parameter *)
  END_VAR
  VAR_OUTPUT
    Q : BOOL := FALSE;  (* first output parameter *)
    ET : TIME := T#0s;  (* second output parameter *)
  END_VAR

  VAR
    STATE : SINT := 0;  (* internal state: 0-reset, 1-counting, 2-set *)
    PREV_IN : BOOL := FALSE;
    CURRENT_TIME, START_TIME : TIME;
  END_VAR

  {__SET_VAR(data__->,CURRENT_TIME,__CURRENT_TIME)}

  IF ((STATE = 0) AND NOT(PREV_IN) AND IN)   (* found rising edge on IN *)
  THEN
    (* start timer... *)
    STATE := 1;
    Q := FALSE;
    START_TIME := CURRENT_TIME;

  ELSE
    (* STATE is 1 or 2 !! *)
    IF (NOT(IN))
    THEN
      ET := T#0s;
      Q := FALSE;
      STATE := 0;

    ELSIF (STATE = 1)
    THEN
      IF ((START_TIME + PT) <= CURRENT_TIME)
      THEN
        STATE := 2;
        Q := TRUE;
        ET := PT;
      ELSE
        ET := CURRENT_TIME - START_TIME;
      END_IF;
    END_IF;

  END_IF;

  PREV_IN := IN;

END_FUNCTION_BLOCK





(****************************************************************

             TOF - Off-delay timing - state machine


              +--------+        +---+   +--------+
       IN     |        |        |   |   |        |
           ---+        +--------+   +---+        +-----------
              t0       t1       t2  t3  t4       t5
              +-------------+   +---------------------+
       Q      |             |   |                     |
           ---+             +---+                     +------
              t0          t1+PT t2                  t5+PT
         PT                 +---+                     +------
          :                /    |       +            /
       ET :               /     |      /|           /
          :              /      |     / |          /
          :             /       |    /  |         /
          0------------+        +---+   +--------+
                       t1           t3           t5


        2                   +---+                     +------
STATE   1              +----+   |   +---+        +----+
        0 -------------+        +---+   +--------+


****************************************************************)

FUNCTION_BLOCK TOF
  VAR_INPUT
    IN : BOOL;  (* first input parameter *)
    PT : TIME;  (* second input parameter *)
  END_VAR
  VAR_OUTPUT
    Q : BOOL := FALSE;  (* first output parameter *)
    ET : TIME := T#0s;  (* second output parameter *)
  END_VAR

  VAR
    STATE : SINT := 0;  (* internal state: 0-reset, 1-counting, 2-set *)
    PREV_IN : BOOL := FALSE;
    CURRENT_TIME, START_TIME : TIME;
  END_VAR

  {__SET_VAR(data__->,CURRENT_TIME,__CURRENT_TIME)}

  IF ((STATE = 0) AND PREV_IN AND NOT(IN))   (* found falling edge on IN *)
  THEN
    (* start timer... *)
    STATE := 1;
    START_TIME := CURRENT_TIME;

  ELSE
    (* STATE is 1 or 2 !! *)
    IF (IN)
    THEN
      ET := T#0s;
      STATE := 0;

    ELSIF (STATE = 1)
    THEN
      IF ((START_TIME + PT) <= CURRENT_TIME)
      THEN
        STATE := 2;
        ET := PT;
      ELSE
        ET := CURRENT_TIME - START_TIME;
      END_IF;
    END_IF;

  END_IF;

  Q := IN OR (STATE = 1);
  PREV_IN := IN;

END_FUNCTION_BLOCK