用西門子SCL語言編程，一些計算過程需要自己編寫函數實現。遇到的問題是：一個函數的輸入值是另一個函數的輸出值，所以我想到用FC調用FC。

目前有三個函數，是FC48,FC4，FC49。在FB40里調用三個函數。

//下面是程序**********************************************紅色的變量是輸入輸出值

FUNCTION_BLOCK FB40 //谷電期蓄能總控制
VAR_OUTPUT
RESULT_Q:INT; //輸出Q量
RESULT_W:INT;
RESULT_Wt:INT;
END_VAR

BEGIN //調用FC48計算Q
RESULT_Q:=FC48(Ai := "A" // IN: INT
,Hdesign_total := "Hdt" // IN: INT
,Wpower_real :="W0" // IN: INT
,Qdesign_total :="Q0" // OUT: INT
); // INT

//調用FC4計算Wpower_real******************************************
RESULT_W:=FC4(Wpower_real_today :="W1" // IN: INT
,Toutdr_offpk_sta_tody :="T01" // IN: INT
,Toutdr_offpk_sta_yesdy := "T02" // IN: INT
,Wpower_real :="W0" // OUT: INT
); // INT

//調用FC49計算Wpower_real_today************************************
RESULT_Wt:=FC49 (Theating_unit_11 := "Q2" // IN: REAL
,Theating_unit_12 := "Q3" // IN: REAL
,Theating_unit_21 := "Q4" // IN: REAL
,Theating_unit_22 := "Q5" // IN: REAL
,Theating_unit_31 := "Q6" // IN: REAL
,Theating_unit_32 := "Q7" // IN: REAL
,Qadd := "Qa" // IN: REAL
,A := "A" // IN: REAL
,Huser :="Hu" // IN: REAL
,Ttime_offpkend_11 := "Q11" // IN: REAL
,Ttime_offpkend_12 := "Q12" // IN: REAL
,Ttime_offpkend_21 := "Q21" // IN: REAL
,Ttime_offpkend_22 := "Q22" // IN: REAL
,Ttime_offpkend_31 := "Q31" // IN: REAL
,Ttime_offpkend_32 := "Q32" // IN: REAL
,Wpower_real_today := "W1" // OUT: REAL
); // REAL
END_FUNCTION_BLOCK


編譯后的錯誤時invalid assignment。在調用FC48和FC4處有問題.

三個FC函數分別編譯都沒有問題。下面是三個函數：

FUNCTION FC48 : INT

VAR_INPUT
Ai:INT;
Hdesign_total:INT;
Wpower_real:INT;
END_VAR

VAR_OUTPUT
Qdesign_total:INT;

END_VAR

BEGIN

FC48:=(Ai*Hdesign_total)*Wpower_real;
Qdesign_total:=FC48;
// Statement Section


END_FUNCTION

/／＊***************************************************

FUNCTION FC4 : INT

VAR_INPUT
Wpower_real_today:INT;
Toutdr_offpk_sta_tody:INT;
Toutdr_offpk_sta_yesdy:INT;

END_VAR
VAR_OUTPUT
Wpower_real:INT;
END_VAR

BEGIN

/／＊******************************************

FUNCTION FC49 : INT



VAR_INPUT
Theating_unit_11:INT;
Theating_unit_12:INT;
Theating_unit_21:INT;
Theating_unit_22:INT;
Theating_unit_31:INT;
Theating_unit_32:INT;
Qadd:INT;
A:INT;//房間面積
Huser:INT;
Ttime_offpkend_11:INT;
Ttime_offpkend_12:INT;
Ttime_offpkend_21:INT;
Ttime_offpkend_22:INT;
Ttime_offpkend_31:INT;
Ttime_offpkend_32:INT;
END_VAR

VAR_OUTPUT
Wpower_real_today:INT;//第二天預計供熱負荷
END_VAR

BEGIN
FC49:=(a*(Theating_unit_11+Theating_unit_12+Theating_unit_21+Theating_unit_22+Theating_unit_31+Theating_unit_32-Ttime_offpkend_11-Ttime_offpkend_12-Ttime_offpkend_21-Ttime_offpkend_22-Ttime_offpkend_31-Ttime_offpkend_32)+Qadd)/(A* Huser);
Wpower_real_today:=FC49;

END_FUNCTION