raw_value is clearly based on the same tach stripe count for DTO and DOD. Perhaps another way to look at it is to observe that 46.5 x 11 = 511.5. That is suspiciously close to "exactly" 512.000 - in other words is a 9-bit binary shift which is arguably what you'd expect a presumably fixed-point microcontroller processor to do to represent two levels of resolution or scaling of the same underlying value.
