RAF is a file format used by the Rigol DG1000Z, DG4000, and DG5000 series signal generators. It is generated by Rigol's UltraStation software.
The format consists of a series of 16-bit values in little-endian order. There is no header of any kind. The values represent integers from 0 to 16383, where 0 is the minimum negative value and 16383 the maximum positive value, and 8192 is 0.
The number of values in a file corresponds to that required for the target device. For example, the DG4000 series has a memory depth of 16K points; this corresponds to 16384 values * 2 bytes = 32768-byte RAF file.