Sorry for not adding the compressed files. I added {$packrecords C} as you suggested, but it still results in the same errors: 96075796 when executing dpfpdd_version () -> (return: One or more parameters passed to the API call are invalid) and 96075789 when executing dpfpdd_query_devices() -> (return: The memory allocated by the application is not big enough for the data which is expected).
Could I have suggested another alternative?
NOTE: I used the test environment in addition to the ones mentioned above, the following configuration: FPC 3.0.4 running on Ubuntu 18.04 LTS amd64, Intel Core I5 2.5Ghz, 6GB RAM and also tested on Windows 7 32bit running on VirtualBox with 1GB RAM.