!--------------------------------------------------------
! Water tank heat control
! Assume constant volume (i.e. water in = water out)
!--------------------------------------------------------
CONFIGURATION
    PLOT_DURATION = 100.0;      ! seconds
    SIM_SCHEDULE_RATE = 0.1;    ! second
    SIM_INC_RATE = 0.01;        ! second
END_CONFIGURATION;

SEGMENT Control

CYCLE_TIME    0.50

!     Name        MIN   MAX
IN    Temperature(32.0, 212.0)
IN    Water_out  (0.0, 10.0)
IN    Temp_error (-90.0, 90.0)
OUT   Gas_valve  (0.0, 10.0)

Initialization
    Gas_valve = 0;
END;

!        Name                     Below    Low   High  Above  Truth
Symbol   Zero        OF Water_out (  0.0,   0.0,   0.0,   2.0,  1.0)
Symbol   Light       OF Water_out (  0.0,   2.0,   3.0,   5.9,  1.0)
Symbol   Medium      OF Water_out (  3.0,   5.0,   6.0,   8.0,  1.0)
Symbol   Heavy       OF Water_out (  6.0,   8.0,  10.0,  10.0,  1.0)

Symbol   VeryCold    OF Temp_error(-90.0, -90.0, -30.0, -20.0,  1.0)
Symbol   Cold        OF Temp_error(-30.0, -20.0, -10.0,   0.0,  1.0)
Symbol   OnTarget    OF Temp_error(-10.0,   0.0,   0.0,  10.0,  1.0)
Symbol   Hot         OF Temp_error(  0.0,  10.0,  20.0,  30.0,  1.0)
Symbol   VeryHot     OF Temp_error( 20.0,  30.0,  90.0,  90.0,  1.0)

!        Name                    Below    Low   High  Above  Truth   Center
Symbol   Off       OF Gas_valve (  0.0,   0.0,   0.0,   2.0,   1.0,   0.0)
Symbol   VeryLow   OF Gas_valve (  0.0,   2.0,   2.0,   4.0,   1.0)
Symbol   Low       OF Gas_valve (  2.0,   4.0,   4.0,   6.0,   1.0)
Symbol   High      OF Gas_valve (  4.0,   6.0,   6.0,   8.0,   1.0)
Symbol   VeryHigh  OF Gas_valve (  6.0,   8.0,  10.0,  10.0,   1.0,  10.0)

!!!!!!!! Rules for controlling Gas_valve
!              Heavy  Medium   Light   Zero
!--------------------------------------------
!  VeryCold     VH      VH      VH      VH
!  Cold         VH      H       H       L  
!  OnTarget     L       VL      VL      Off
!  Hot          Off     Off     Off     Off
!  VeryHot      Off     Off     Off     Off
!
!

IF Temp_error IS VeryCold
THEN Gas_valve IS VeryHigh

IF Temp_error IS Cold AND Water_out IS Heavy
THEN Gas_valve IS VeryHigh

IF Temp_error IS Cold AND Water_out IS Medium
THEN Gas_valve IS High

IF Temp_error IS Cold AND Water_out IS Light
THEN Gas_valve IS High

IF Temp_error IS Cold AND Water_out IS Zero
THEN Gas_valve IS Low

IF Temp_error IS OnTarget AND Water_out IS Heavy
THEN Gas_valve IS High

IF Temp_error IS OnTarget AND Water_out IS Medium
THEN Gas_valve IS Low

IF Temp_error IS OnTarget AND Water_out IS Light
THEN Gas_valve IS VeryLow

IF Temp_error IS OnTarget AND Water_out IS Zero
THEN Gas_valve IS Off

IF Temp_error IS Hot
THEN Gas_valve IS Off

IF Temp_error IS VeryHot
THEN Gas_valve IS Off

END Control;