我正在尝试构建一个函数,对 TwinCAT 中任何类型的一维数组求和。
我对指针相对缺乏经验,所以答案可能是显而易见的,但我找不到任何解决方案。我通读了所有这些内容,它们对我有所帮助。
T_ARG Convert Byte arrays The Wonders of ANY
我的概念代码适用于 INT 数组,但我意识到我必须为每个数据类型编写一个 FOR 循环才能使其工作,这似乎是错误的。 我还想避免在 FOR 循环中使用 CASE,因为这看起来效率很低。
是否可以有一个(未设置类型的)指针指向(特定类型的)指针?在 C 语言中看起来可以,但对于 IEC-61131 不确定。
FUNCTION fn_SumArray : DINT
VAR_INPUT
inArr : ANY;
inElem : ANY;
END_VAR
VAR
i : DINT := 0;
stepsize : DINT :=1;
pLREAL : POINTER TO LREAL; //64 bit
pREAL : POINTER TO REAL; //32 bit
pBYTE : POINTER TO BYTE; //8 bit
pWORD : POINTER TO WORD; //16 bit
pDWORD : POINTER TO DWORD; //32 bit
pLWORD : POINTER TO LWORD; //64 bit
pSINT : POINTER TO SINT; //8 bit
pUSINT : POINTER TO USINT; //8 bit
pINT : POINTER TO INT; //16 bit
pUINT : POINTER TO UINT; //16 bit
pDINT : POINTER TO DINT; //32 bit
pUDINT : POINTER TO UDINT; //32 bit
pLINT : POINTER TO LINT; //64 bit
pULINT : POINTER TO ULINT; //64 bit
END_VAR
--------------------------------------------------
CASE inElem.TypeClass OF
__SYSTEM.TYPE_CLASS.TYPE_LREAL:
stepsize := 8;
//set generic pointer here
__SYSTEM.TYPE_CLASS.TYPE_INT:
stepsize := 2;
//set generic pointer here
ELSE
fn_SumArray :=0;
END_CASE;
FOR i := 0 TO inArr.diSize-1 BY stepsize DO
genericPointer:= ADR(inarr.pValue[i]);
fn_SumArray := fn_SumArray +genericPointer^;
END_FOR;
最佳答案
据我所知,您必须为您想要涵盖的所有类型重复该代码。 CODESYS 没有真正的通用编程,所以它就是这样:
(* DECLARATION *)
METHOD fn_SumArray : BOOL // if TRUE, then error
VAR_INPUT
arr_first : ANY_NUM;
arr_size : DINT;
sum_out : ANY_NUM;
END_VAR
VAR
i : DINT;
ptr_arr: NUMBER_POINTER; // just a UNION with all number type pointers
ptr_sum: NUMBER_POINTER;
END_VAR
(* IMPLEMENTATION *)
IF (arr_first.TypeClass <> sum_out.TypeClass) THEN
fn_SumArray := TRUE;
// set all bytes of sum_out to 0
FOR i := 0 TO sum_out.diSize - 1 DO
sum_out.pValue[i] := 0;
END_FOR
RETURN;
END_IF
CASE arr_first.TypeClass OF
__SYSTEM.TYPE_CLASS.TYPE_LREAL:
ptr_arr._LREAL := arr_first.pValue;
ptr_sum._LREAL := sum_out.pValue;
ptr_sum._LREAL^ := 0;
FOR i := 0 TO arr_size - 1 DO
ptr_sum._LREAL^ := ptr_sum._LREAL^ + ptr_arr._LREAL[i];
END_FOR
// Repeat the above for all ...
ELSE
fn_SumArray := TRUE;
// set all bytes of sum_out to 0
FOR i := 0 TO sum_out.diSize - 1 DO
sum_out.pValue[i] := 0;
END_FOR
END_CASE;
// A POINTER for every data type of ANY_NUM
// PS. A pointer has the exact same size for any type
TYPE NUMBER_POINTER :
UNION
// floating
_REAL: POINTER TO REAL;
_LREAL: POINTER TO LREAL;
// unsigned
_USINT: POINTER TO USINT;
_UINT: POINTER TO UINT;
_UDINT: POINTER TO UDINT;
_ULINT: POINTER TO ULINT;
// signed
_SINT: POINTER TO SINT;
_INT: POINTER TO INT;
_DINT: POINTER TO DINT;
_LINT: POINTER TO LINT;
END_UNION
END_TYPE
(* DECLARATION *)
PROGRAM PLC_PRG
VAR CONSTANT
SIZE: DINT := 50;
END_VAR
VAR
i: DINT;
arr_int: ARRAY [0..(SIZE - 1)] OF INT;
sum_int: INT;
arr_dint: ARRAY [0..(SIZE - 1)] OF DINT;
sum_dint: DINT;
arr_real: ARRAY [0..(SIZE - 1)] OF REAL;
sum_real: REAL;
first_run: BOOL := TRUE;
sum_test: REAL;
test_failed: BOOL;
END_VAR
(* IMPLEMENTATION *)
IF (first_run) THEN
first_run := FALSE;
FOR i := 0 TO SIZE - 1 DO
arr_int[i] := DINT_TO_INT(i);
arr_dint[i] := i * 10;
arr_real[i] := DINT_TO_REAL(i) / 10;
END_FOR
END_IF
fn_SumArray(arr_first := arr_int[0], arr_size := SIZE, sum_out := sum_int);
sum_test := 0;
FOR i := 0 TO SIZE - 1 DO
sum_test := sum_test + arr_int[i];
END_FOR
IF (sum_int <> REAL_TO_INT(sum_test)) THEN
test_failed := TRUE;
END_IF
fn_SumArray(arr_first := arr_dint[0], arr_size := SIZE, sum_out := sum_dint);
sum_test := 0;
FOR i := 0 TO SIZE - 1 DO
sum_test := sum_test + DINT_TO_REAL(arr_dint[i]);
END_FOR
IF (sum_dint <> REAL_TO_DINT(sum_test)) THEN
test_failed := TRUE;
END_IF
fn_SumArray(arr_first := arr_real[0], arr_size := SIZE, sum_out := sum_real);
sum_test := 0;
FOR i := 0 TO SIZE - 1 DO
sum_test := sum_test + arr_real[i];
END_FOR
IF (sum_real <> sum_test) THEN
test_failed := TRUE;
END_IF
上述程序的结果:
如果为每种类型编写相同的代码太乏味,您始终可以使用脚本来自动执行此操作:
#!/usr/bin/env python3
code_template = \
"""CASE arr_first.TypeClass OF
{0}
ELSE
\tfn_SumArray := TRUE;
\tFOR i := 0 TO sum_out.diSize - 1 DO
\t\tsum_out.pValue[i] := 0;
\tEND_FOR
END_CASE;
"""
case_template = \
"""\t__SYSTEM.TYPE_CLASS.TYPE{0}:
\t\tptr_arr.{0} := arr_first.pValue;
\t\tptr_sum.{0} := sum_out.pValue;
\t\tptr_sum.{0}^ := 0;
\t\tFOR i := 0 TO arr_size - 1 DO
\t\t\tptr_sum.{0}^ := ptr_sum.{0}^ + ptr_arr.{0}[i];
\t\tEND_FOR
"""
types = ['_REAL', '_LREAL', '_USINT', '_UINT', '_UDINT', '_ULINT', '_SINT', '_INT', '_DINT', '_LINT']
cases = [case_template.format(t) for t in types]
code = code_template.format(''.join(cases))
print(code)
只需使用 python 3.x 运行上述脚本,您将获得脚本中列出的类型的 case 语句代码。
关于pointers - TwinCAT 指针指向未定义类型的指针?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/71886604/