In Do-more, when you cast to a LARGER size, the ID must ALIGN on that size. Hence, to cast a 16 bit DLV to a 32 bit REAL, it must align on DWORD, meaning the ID must be EVEN (DLV1400:R or DLV1402:R, but NOT DLV1401:R.
This is the nature of the microprocessor.
Hence, you will have to tweak your memory map of your DLV, aligning any REAL or DWORD sized integers on EVEN DLV IDs.