lib/pid_st.txt
author Mario de Sousa <msousa@fe.up.pt>
Wed, 01 Aug 2012 08:33:58 +0100
changeset 617 43e00c10dc49
parent 276 1679f514f38a
permissions -rwxr-xr-x
Change code formatting (alignment)
276
1679f514f38a Updating origin and license info of library fuctions.
Mario de Sousa <msousa@fe.up.pt>
parents: 192
diff changeset
     1
(* Following taken directly from the IEC 61131.3 draft standard *)
1679f514f38a Updating origin and license info of library fuctions.
Mario de Sousa <msousa@fe.up.pt>
parents: 192
diff changeset
     2
1679f514f38a Updating origin and license info of library fuctions.
Mario de Sousa <msousa@fe.up.pt>
parents: 192
diff changeset
     3
(*
1679f514f38a Updating origin and license info of library fuctions.
Mario de Sousa <msousa@fe.up.pt>
parents: 192
diff changeset
     4
 * An IEC 61131-3 IL and ST compiler.
1679f514f38a Updating origin and license info of library fuctions.
Mario de Sousa <msousa@fe.up.pt>
parents: 192
diff changeset
     5
 *
1679f514f38a Updating origin and license info of library fuctions.
Mario de Sousa <msousa@fe.up.pt>
parents: 192
diff changeset
     6
 * Based on the
1679f514f38a Updating origin and license info of library fuctions.
Mario de Sousa <msousa@fe.up.pt>
parents: 192
diff changeset
     7
 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
1679f514f38a Updating origin and license info of library fuctions.
Mario de Sousa <msousa@fe.up.pt>
parents: 192
diff changeset
     8
 *
1679f514f38a Updating origin and license info of library fuctions.
Mario de Sousa <msousa@fe.up.pt>
parents: 192
diff changeset
     9
 *)
1679f514f38a Updating origin and license info of library fuctions.
Mario de Sousa <msousa@fe.up.pt>
parents: 192
diff changeset
    10
192
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    11
 FUNCTION_BLOCK PID
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    12
   VAR_INPUT
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    13
     AUTO : BOOL ;        (* 0 - manual , 1 - automatic *)
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    14
     PV : REAL ;          (* Process variable *)
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    15
     SP : REAL ;          (* Set point *)
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    16
     X0 : REAL ;          (* Manual output adjustment - *)
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    17
                          (* Typically from transfer station *)
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    18
     KP : REAL ;          (* Proportionality constant *)
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    19
     TR : REAL ;          (* Reset time *)
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    20
     TD : REAL ;          (* Derivative time constant *)
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    21
     CYCLE : TIME ;       (* Sampling period *)
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    22
   END_VAR
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    23
   VAR_OUTPUT XOUT : REAL; END_VAR
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    24
   VAR ERROR : REAL ;        (* PV - SP *)
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    25
       ITERM : INTEGRAL ;    (* FB for integral term  *)
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    26
       DTERM : DERIVATIVE ;  (* FB for derivative term *)
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    27
   END_VAR
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    28
   ERROR := PV - SP ;
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    29
   (*** Adjust ITERM so that XOUT := X0 when AUTO = 0 ***)
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    30
   ITERM (RUN := AUTO, R1 := NOT AUTO, XIN := ERROR,
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    31
          X0 := TR * (X0 - ERROR), CYCLE := CYCLE) ;
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    32
   DTERM (RUN := AUTO, XIN := ERROR, CYCLE := CYCLE) ;
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    33
   XOUT := KP * (ERROR + ITERM.XOUT/TR + DTERM.XOUT*TD) ;
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    34
 END_FUNCTION_BLOCK
c6c2a3d487ac Adding inclusion of function blocks defined in AnnexF into library blocks
lbessard
parents:
diff changeset
    35