ISPSoft User Manual Additional remark (a) According to the above principle, 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 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 careful about the correctness of the data.
(b) The data type of a symbol in a function block in a project for an AH series CPU module can be POINTER. Please refer to section 7.2.4 for more information. (c) For AS5xx and DVPxxMC series, if the data length of P_Var (in the caller) is shorter 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 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 highest bits which exceeds the length of FB_Var is overwritten as 0. Users have to be more careful about the correctness of the data. 7.2.4 Index Type Symbol Variables 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. 7-14