subroutine Drawworks_Solver
    
    Use CDrillingConsoleVariables
    Use CDataDisplayConsoleVariables
    Use CHoistingVariables
    Use CUnityInputs
    Use Drawworks_VARIABLES
    Use CHookVariables
    Use CWarningsVariables
    Use COperationConditionEnumVariables
    Use CSlipsEnumVariables
    Use CElevatorConnectionEnumVariables
    Use CTdsConnectionModesEnumVariables
    Use CTdsElevatorModesEnumVariables
    Use TD_DrillStemComponents
    Use TD_WellGeometry
    Use CWarningsVariables
    Use TD_GeneralData
    Use CSounds
    
	IMPLICIT NONE
    
    
    Integer :: j
    Integer :: CrownCollision_Status , FloorCollision_Status , CrownWarning_Status , FloorWarning_Status
    real    :: time
    
    
    
    
    
!>>>>>>>>>>>>>>>>>>>> N_Ref <<<<<<<<<<<<<<<<<<<<<<<<

    Drawworks%N_Throtle     = DrillingConsole%DWThrottle                               ![rpm]
    Drawworks%N_Accelarator = (DrillingConsole%DWAcceleretor/100.0)*965.0              ![rpm]
    !print* , 'Drawworks%N_Throtle=' , Drawworks%N_Throtle
    !print* , 'DWAcceleretor=' , DWAcceleretor
    !print* , 'Drawworks%N_Accelarator=' , Drawworks%N_Accelarator
    IF (Drawworks%N_Throtle>Drawworks%N_Accelarator) THEN
        Drawworks%N_new = Drawworks%N_Throtle
        !print* , 'Drawworks%N_Throtle'
    ELSE
        Drawworks%N_new = Drawworks%N_Accelarator
        !print* , 'Drawworks%N_Accelarator'
    END IF
    if (((Drawworks%N_new-Drawworks%N_old)/Drawworks%time_step)>193.) then
        Drawworks%N_ref = (193.*Drawworks%time_step)+Drawworks%N_old
    else if (((Drawworks%N_old-Drawworks%N_new)/Drawworks%time_step)>193.) then
        Drawworks%N_ref = (-193.*Drawworks%time_step)+Drawworks%N_old
    else
        Drawworks%N_ref = Drawworks%N_new
    end if
    Drawworks%N_old     = Drawworks%N_ref
    !print* , 'Drawworks%N_ref=' , Drawworks%N_ref
    
    
    
    
    Call Drawworks_INPUTS
    
    
    ! Drawworks Malfunction ----> Drive Motor Failure
    Call DWMalfunction_MotorFailure
    
    
    
    
    !=====> Drawworks Gears Abuse
    if ( DW_OldTransMode==0 .and. Drawworks%TransMode/=0 .and. Drawworks%w_drum/=0. .and. Drawworks%ClutchMode/=0 ) then
        Call Activate_DrawworksGearsAbuse()
        Drawworks%SoundGearCrash = .true.
        Call SetSoundDwGearCrash(Drawworks%SoundGearCrash)
        Drawworks%ManualBreak  = 100.
        !Drawworks%N_ref       = 0.
        Call DWFixModeMotion
        Drawworks%SoundRev = INT(Drawworks%w_drum)  ![rpm] , Integer
        Call SetSoundDwRev( Drawworks%SoundRev )
        return
    else
        Drawworks%SoundGearCrash = .false.
        Call SetSoundDwGearCrash(Drawworks%SoundGearCrash)
    end if
    if ( DrawworksGearsAbuse==1 ) then
        return
    end if
    
    
    
    
    
    Call Drawworks_Direction
    
    
    
    
    
!====================================================
!               Collision & Warning
!====================================================
     if ( CrownCollision == .false. ) then
         CrownCollision_Status = 0
     end if
     if ( FloorCollision == .false. ) then
         FloorCollision_Status = 0
     end if
     
     !if ( CrownWarning == .false. ) then
     !    CrownWarning_Status = 0
     !end if
     !if ( FloorWarning == .false. ) then
     !    FloorWarning_Status = 0
     !end if
     
     
     
     
     
     
     
     !====================================================
     !        Crown Collision (Max_Hook_Height)
     !====================================================
     if ( ((3.280839895*Drawworks%Hook_Height)>=Drawworks%max_Hook_Height) .and. (any(DW_DrillModeCond==(/3,4,7,10,11,12,14/))) ) then
         if ( CrownCollision_Status==0 .and. Drawworks%motion==1 ) then
           Call Activate_CrownCollision()
           CrownCollision_Status = 1
           Drawworks%SoundCrownCollision = .true.
           Call SetSoundCrownCollision(Drawworks%SoundCrownCollision)
         else
           Drawworks%SoundCrownCollision = .false.
           Call SetSoundCrownCollision(Drawworks%SoundCrownCollision)
         end if
         do While ( CrownCollision==1 )
             Call DWFixModeMotion
         end do
         if ( Drawworks%motion==-1 ) then
               Drawworks%Hook_Height_final = 3.280839895*Drawworks%Hook_Height    ![ft]
               Call Set_HookHeight(real(Drawworks%Hook_Height_final))
         else
               Call DWFixModeMotion
         end if
         return
     end if
     
     
     
     
     
     
     
     !====================================================
     !        Floor Collision (Min_Hook_Height)
     !====================================================
     if ( ((3.280839895*Drawworks%Hook_Height)<=Drawworks%min_Hook_Height) .and. (any(DW_DrillModeCond==(/3,4,7,10,11,12,14/)))  ) then
         if ( FloorCollision_Status==0 .and. Drawworks%motion==-1 ) then
           Call Activate_FloorCollision()
           Drawworks%SoundFloorCollision = .true.
           Call SetSoundFloorCollision(Drawworks%SoundFloorCollision)
           FloorCollision_Status = 1
         else
           Drawworks%SoundFloorCollision = .false.
           Call SetSoundFloorCollision(Drawworks%SoundFloorCollision)
         end if
         Do While ( FloorCollision ==1 )
             Call DWFixModeMotion
         End Do
         if ( Drawworks%motion==1 ) then
               Drawworks%Hook_Height_final = 3.280839895*Drawworks%Hook_Height    ![ft]
               Call Set_HookHeight(real(Drawworks%Hook_Height_final))
         else
               Call DWFixModeMotion
         end if
         return
     end if
     
     
     
     
     
     
     
     
     !====================================================
     !                   Crown Warning
     !====================================================
     if ( ((3.280839895*Drawworks%Hook_Height)>=Drawworks%max_Hook_Height) .and. (any(DW_DrillModeCond==(/1,2,5,6,8,9,13/))) ) then
         !if ( crownwarning_Status==0 .and. Drawworks%motion==1 ) then  ??????????
         !  Call Activate_crownwarning()   ??????????
         !Drawworks%SoundCrownCollision = .true.
         !Call SetSoundCrownCollision(Drawworks%SoundCrownCollision)
         !  CrownWarning_Status = 1   ??????????
         !else
         !  Drawworks%SoundCrownCollision = .false.
         !Call SetSoundCrownCollision(Drawworks%SoundCrownCollision)
         !end if   ??????????
         if ( Drawworks%motion==-1 ) then
               Drawworks%Hook_Height_final = 3.280839895*Drawworks%Hook_Height    ![ft]
               Call Set_HookHeight(real(Drawworks%Hook_Height_final))
         else
               Call DWFixModeMotion
         end if
         return
     end if
     
     
     
     
     
     
     
     !====================================================
     !                  Floor Warning
     !====================================================
     if ( ((3.280839895*Drawworks%Hook_Height)<=Drawworks%min_Hook_Height) .and. (any(DW_DrillModeCond==(/1,2,5,6,8,9,13/)))  ) then
         !if ( floorwarning_Status==0 .and. Drawworks%motion==-1 ) then  ??????????
         !  Call Activate_floorwarning()   ??????????
         !Drawworks%SoundCrownCollision = .true.
         !Call SetSoundCrownCollision(Drawworks%SoundCrownCollision)
         !  floorwarning_Status = 1   ??????????
         !else
         !Drawworks%SoundCrownCollision = .false.
         !Call SetSoundCrownCollision(Drawworks%SoundCrownCollision)
         !end if   ??????????
         if ( Drawworks%motion==1 ) then
               Drawworks%Hook_Height_final = 3.280839895*Drawworks%Hook_Height    ![ft]
               Call Set_HookHeight(real(Drawworks%Hook_Height_final))
         else
               Call DWFixModeMotion
         end if
         return
     end if
     
     
     
     
     
     
     
     
     
     
     !====================================================
     ! ELEVATOR CONNECTION STRING (SLIPS SET , No Motion)
     !====================================================
     if ( Hoisting%DriveType==1 .and. Get_Slips() == SLIPS_SET_END .and. Get_ElevatorConnection() == ELEVATOR_CONNECTION_STRING .and. Drawworks%motion/=-1 ) then
         !if ( Drawworks%motion/=-1 ) then
               Call DWFixModeMotion
               return
         !end if
     end if
     
     if ( Hoisting%DriveType==0 .and. Get_Slips() == SLIPS_SET_END .and. (Get_TdsConnectionModes()==TDS_CONNECTION_NOTHING .and. Get_TdsElevatorModes()==TDS_ELEVATOR_CONNECTION_STRING) .and. Drawworks%motion/=-1 ) then
         !if ( Drawworks%motion/=-1 ) then
               Call DWFixModeMotion
               return
         !end if
     end if
     
     
     
     
     
     
     
     
     
     
     
     !====================================================
     !       RAM & ToolJoint Collision (Top of RAM)
     !====================================================
      Do j = 2,4  !startup problem ???????
          if ( TD_BOPElementNo(j)/=0 ) then
             if ( ((TD_BOPHeight(j)-TD_BOPThickness)<=(TD_DrillStems(TD_BOPElementNo(j))%TopDepth+TD_DrillStems(TD_BOPElementNo(j))%ToolJointRange)) .and. ((TD_BOPHeight(j)-TD_BOPThickness)>TD_DrillStems(TD_BOPElementNo(j))%TopDepth) .and. (TD_BOPRamDiam(j)<(2.d0*12.d0*TD_DrillStems(TD_BOPElementNo(j))%RtoolJoint)) ) then
                 if ( Drawworks%motion==1 ) then
                    Drawworks%Hook_Height_final = 3.280839895*Drawworks%Hook_Height    ![ft]
                    Call Set_HookHeight(real(Drawworks%Hook_Height_final))
                 else
                    Call DWFixModeMotion
                 end if
                 return
             end if
          end if
      End Do
     
     
     
     
     
     
      
     
     
     !====================================================
     !      RAM & ToolJoint Collision (Bottom of RAM)
     !====================================================
      Do j = 2,4
          if ( TD_BOPElementNo(j)/=0 ) then
             if ( ((TD_BOPHeight(j)+TD_BOPThickness)>=(TD_DrillStems(TD_BOPElementNo(j))%DownDepth-TD_DrillStems(TD_BOPElementNo(j))%ToolJointRange)) .and. ((TD_BOPHeight(j)+TD_BOPThickness)<TD_DrillStems(TD_BOPElementNo(j))%DownDepth) .and. (TD_BOPRamDiam(j)<(2.d0*12.d0*TD_DrillStems(TD_BOPElementNo(j))%RtoolJoint)) ) then
                 if ( Drawworks%motion==-1 ) then
                    Drawworks%Hook_Height_final = 3.280839895*Drawworks%Hook_Height    ![ft]
                    Call Set_HookHeight(real(Drawworks%Hook_Height_final))
                 else
                    Call DWFixModeMotion
                 end if
                 return
             end if
          end if
      End Do
     
     
      
      
      
      
      
      !====================================================
      !               TopDrive (TdsStemIn)
      !====================================================
      if ( (Hoisting%DriveType==0) .and. (Get_TdsStemIn()) .and. Get_Slips() == SLIPS_SET_END ) then
         if ( Drawworks%motion==1 ) then
               Drawworks%Hook_Height_final = 3.280839895*Drawworks%Hook_Height    ![ft]
               Call Set_HookHeight(real(Drawworks%Hook_Height_final))
         else
               Call DWFixModeMotion
         end if
         return
      end if
      
      
      
      
      
     
     
     
     
     
     
     !print* , 'Drawworks%Hook_Height_final15=' , Drawworks%Hook_Height_final , TD_DrillStemBottom , int(TD_DrillStemBottom*1000.d0) , int((TD_WellTotalLength+TD_DlMax)*1000.d0) , (TD_WellTotalLength+TD_DlMax) , Drawworks%motion , StringIsBottomOfWell
     !=====> BottomHole ROP Condition
     if ( (int(TD_DrillStemBottom*10000.d0)>=(int((TD_WellTotalLength+TD_DlMax)*10000.d0))) .and. (Drawworks%motion==-1 .or. Drawworks%motion==0) ) then
        !print* , 'Drawworks%Hook_Height_final10=' , Drawworks%Hook_Height_final , TD_DrillStemBottom , (TD_WellTotalLength+TD_DlMax)
        if ( StringIsBottomOfWell==0 ) then
            Drawworks%Hook_Height_final = Drawworks%Hook_Height_final+(TD_DrillStemBottom-(TD_WellTotalLength+TD_DlMax))
            StringIsBottomOfWell = 1
            !print* , 'Drawworks%Hook_Height_final11=' , Drawworks%Hook_Height_final , TD_DrillStemBottom , (TD_WellTotalLength+TD_DlMax)
        end if
        Call DWFixModeMotion
        !print* , 'Drawworks%Hook_Height_final12=' , Drawworks%Hook_Height_final
        !print* , 'bef return1'
        return
        !print* , 'aft return1'
     else
         StringIsBottomOfWell = 0
     end if
     
     
     
      
     
     
     
     
     Drawworks%Hook_Height_final = 3.280839895*Drawworks%Hook_Height      ![ft]
     call Set_HookHeight(real(Drawworks%Hook_Height_final))
     Drawworks%HookHeight_graph_output = 0.1189*((3.280839895*Drawworks%Hook_Height)-28.0)-2.6   ![ft]
     
    
     !print*, 'Drawworks%motion=' , Drawworks%motion
     !print*, 'Drawworks%Hook_Height_final=' , Drawworks%Hook_Height_final
     !print*, 'Drawworks%ia_new=' , Drawworks%ia_new
     !print*, 'Drawworks%ia_ref=' , Drawworks%ia_ref
     !print*, 'Drawworks%dia=' , Drawworks%dia
     !print*, 'Drawworks%dw=' , Drawworks%dw
     !print*, 'Drawworks%w_new=' , Drawworks%w_new
     
     
end subroutine Drawworks_Solver