ISPSoft User Manual

ISPSoft User Manual
the caller) is four elements. The array type of FB_Var (in the function block) is INT,
and the size of the array for FB_Var (in the function block) is three elements.
The basic principles for the symbols whose data types are ARRAY are satisfied. As a result,
the array types are legal.
Example 7: The array type of P_Var is WORD, and the size of the array for P_Var is two elements.
The data type of FB_Var is WORD (not ARRAY).
The second special principle for the symbols whose data types are ARRAY is satisfied. As a
result, the array type and the data type are legal.
Example 8: The array type of P_Var is WORD, and the size of the array for P_Var is four
elements. The data type of FB_Var is DWORD (not ARRAY).
The third special principle for the symbols whose data types are ARRAY is satisfied. As a
result, the array type and the data type are legal.
ㄨ Example 9: The array type of P_Var is DINT, and the size of the array for P_Var is four elements.
The array type of FB_Var is INT, and the size of the array for FB_Var is two
elements.
The array type of P_Var is not the same as the array type of FB_Var. As a result, the array
types are illegal.
Example 10: The data type of P_Var is DWORD (not ARRAY). The array type of FB_Var is
WORD, and the size of the array for FB_Var is two elements.
The third special principle for the symbols whose data types are ARRAY is satisfied. As a
result, the data type and the array type are legal.
Additional remark
(a) If the principles above are satisfied, the data length of P_Var (in the caller) is larger than that of
FB_Var (in function block), and the value of P_Var is sent to FB_Var, the values of the bits
starting from the lowest bit in P_Var are retrieved, and the number of values retrieved conforms
to the data length of FB_Var. If principles above are satisfied, the data length of P_Var (in the
caller) is larger than that of FB_Var (in function block), and the value of FB_Var is sent to P_Var,
the values of the bits starting from the lowest bit in P_Var are overwritten, the number of values
overwritten conforms to the data length of FB_Var, and the values which are not overwritten
remains unchanged. Users have to be more careful about the correctness of the data when they
use P_Var and FB_Var.
(b) The data type of a symbol in a function block in a project for an AH500 series CPU module can
be POINTER. Please refer to section 7.2.4 for more information.
7.2.4 Symbol Whose Data Type is POINTER, T_POINTRER,
C_POINTER, or HC_POINTER
A symbol whose data type is POINTER, T_POINTER, C_POINTER, or HC_POINTER functions to
send the symbol or the device address specified by the caller to the function block. The use of a
symbol whose data type is POINTER, T_POINTER, C_POINTER, or HC_POINTER is quite
different from the use of a symbol whose data type is a general data type. A symbol whose data type
is a general data type in a function block either receives the value from the device specified by the
caller or sends the operation result to the device specified by the caller. If the data type of a pin of a
function block is POINTER, T_POINTER, C_POINTER, or HC_POINTER, the data sent to the
function block will be the symbol or the device address assigned to the pin. As a result, the object
processed in a function block is the object which is specified.
The caller assigns D0 to pVAR in the function block, and the data type of pVAR in the function block
is POINTER, T_POINTER, C_POINTER, or HC_POINTER, as shown in the figure below. If the
function block is called and executed, pVAR in the function block will be regarded as D0.
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