This is an enumeration that defines the type of the data behind a data reference. This allows you to sanity check that the data type matches what you expect. But for the most part, you will know the type of data you are expecting from the online documentation.

Data types each take a bit field; it is legal to have a single dataref be more than one type of data. Whe this happens, you can pick any matching get/set API.

xplmType_Unknown"0" Data of a type the current XPLM doesn't do.
xplmType_Int"1" A single 4-byte integer, native endian.
xplmType_Float"2" A single 4-byte float, native endian.
xplmType_Double"4" A single 8-byte double, native endian.
xplmType_FloatArray"8" An array of 4-byte floats, native endian.
xplmType_IntArray"16" An array of 4-byte integers, native endian.
xplmType_Data"32" A variable block of data.