In the TIA Portal, you can access (read/write) all members of any instance DB that was created from an FB from a library from AX.
NOTICE
There is one restriction: If you have an FB in the TIA Portal that represents a class, it is not permitted to write to the members in the TIA Portal. Only reading is possible. This applies to access in the TIA Portal code blocks and also when monitoring blocks. Modifying the operand is also impossible.
NAMESPACE ExampleLibrary
FUNCTION_BLOCK WrapperFB
VAR
classMember : ExampleClass; // only read access in TIA Portal
varInt : INT; // read and write accesses are possible
varUDT : UDT1; // read and write access possible
END_VAR
END_FUNCTION_BLOCK
END_NAMESPACE