ODATA and FLTP / Edm.Double

Hi odata specialists,
I'm new to odata and have a beginners question about data types.

I try to transfer data of SAP standard table AFVV.

(The argument '1.0000000000000000E +' can not be interpreted as a number.)

Then I analysed the fields and found, that this only happens, if I include a field which is set to type FLTP, e.g. AFVV-BEARZ, data element BEARZEIT, floating point, len=16, dec=16.

While the import of the DDIC structure AFVV the type was automatically set to Edm.Double like this

Linking to other types leads to a generation error. Only Edm.Double works but fails while triggering the odata service by my URI

/sap/opu/odata/SAP/ZPP_TEST_ORDERS_SRV/AfkoSet('100000035')/ToAfvv

Can you please give me a hint about my error ? How to proceed ?

By the way: I am using SAP_GWFND 750/SP3 on a SAP ERP ECC6.08 system.

Thank you very much !

Best regards,

Markus