鍙橀噺绫诲瀷

VAR
 iLoc1:INT; (* 1. Local Variable*)
END_VAR

VAR_INPUT 
iIn1:INT (* 1. Inputvariable*)
END_VAR

VAR_OUTPUT 
iOut1:INT; (* 1. Outputvariable*)
END_VAR

fun(iIn1 := 1, iIn2 := 2, iOut1 => iLoc1, iOut2 => iLoc2);

VAR_IN_OUT 
iInOut1:INT; (* 1. Inputoutputvariable *)
END_VAR

FUNCTION funManipulate : BOOL
VAR_IN_OUT    
sReadWrite : STRING(16); (* Can be read or written here in POU *)    
dwVarReadWrite : DWORD; (* Can be read or written here in POU *)
END_VAR
VAR_IN_OUT CONSTANT    
c_sReadOnly : STRING(16); (* Constant string variable can only be read here in POU *)
END_VAR
sReadWrite := 'String_from_POU';
dwVarReadWrite := STRING_TO_DWORD(c_sReadOnly);
PROGRAM PRG_A
VAR    
sVarFits : STRING(16);    
sValFits : STRING(16) :='1234567890123456';    
dwVar: DWORD;
END_VAR
// The following line of code causes the compiler error C0417:
// C0417: VAR_IN_OUT parameter 'sReadWrite' needs a variable with write access as input.
funManipulate(sReadWrite:='1234567890123456', c_sReadOnly:='1234567890123456', dwVarReadWrite := dwVar);
// Correct code
funManipulate(sReadWrite := sValFits, c_sReadOnly := '23', dwVarReadWrite := dwVar);funManipulate(sReadWrite := sVarFits, c_sReadOnly := sValFits, dwVarReadWrite :=dwVar);

FUNCTION_BLOCK FB_DoSomething 
VAR_EXTERNAL 
iVarExt1:INT; (* 1st external variable *)
END_VAR

METHOD meth_last : INT
VAR_INPUT  
iVar : INT;
END_VAR
VAR_INST  
iLast : INT := 0;
END_VA
Rmeth_last := iLast;
iLast := iVar;