C
C
C           MODEL OF PERFECT THREE-WAY VALVE
C
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C     SAMPLE INPUT AND OUTPUT VALUES
C
C     PARAMETERS                       SAMPLE VALUES
C     NONE
C
C     INPUTS
C     XIN(1) T1                            73.65
C     XIN(2) TSET                          68.65
C     XIN(3) T2                            40.00
C     XIN(4) dM2                            2.384
C
C     OUTPUTS
C     OUT(1) TW: water temperature         68.65
C     OUT(2) dM1: water mass flow rate      2.03
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC


!  This component has been assigned Type Number 209. If that number conflicts with 
!  another user Type number, you will need to change it and recompile the appropriate
!  dll.

      SUBROUTINE TYPE209(TIME,XIN,OUT,T,DTDT,PAR,INFO,ICNTRL,*)

!DEC$ATTRIBUTES DLLEXPORT :: TYPE209


C
      DOUBLE PRECISION XIN,OUT
	DIMENSION XIN(4),OUT(2),INFO(15)
C

!    Set the version information for TRNSYS
      IF (INFO(7).EQ.-2) THEN
	  INFO(12) = 15
	  RETURN 1
	ENDIF


C                  INPUTS
C
C             HOT WATER TEMPERATURE
      T1=XIN(1)
C             TEMPERATURE SET POINT
      TW=XIN(2)
C             RETURN OR "COLD" WATER TEMPERATURE
      T2=XIN(3)
C             WATER MASSFLOWRATE
      XM2=XIN(4)
C
      IF(TW.GE.T1) THEN
C             SET POINT HIGHER THAN HOT WATER TEMPERATURE
      XM1=XM2
      TW=T1
C
      ELSE
           IF(TW.LE.T2) THEN
C             SET POINT LOWER THAN RETURN OR COLD WATER TEMPERATURE 
           XM1=0.
           TW=T2
C
           ELSE
           XM1=XM2*(TW-T2)/(T1-T2)
           ENDIF
C
      ENDIF
C
C                  OUTPUTS
C
C             ACTUAL WATER TEMPERATURE
      OUT(1)=TW
C             HOT WATER MASSFLOW RATE
      OUT(2)=XM1
C
      RETURN 1
      END