STRUCT with relative addressing - Manual - AX2TIA - This package contains the documentation for ax2tia - Converting SIMATIC AX libraries to TIA Portal libraries,

Using such a structure will result in an error either during compile or at the latest during conversion of the library to the TIA Portal.

TYPE
    ioStruct : STRUCT
        i  AT %B0 : INT;
        w  AT %B2 : WORD;
    END_STRUCT;
END_TYPE