ANT Forum

Due to some confusion around the use of Native Overrides in Developer Data we have updated the FIT Protocol Document to clarify the usage. (see section 4.2.1.5.2.1 of Flexible & Interoperable Data Transfer (FIT) Protocol Document)

Developer Fields that override native FIT fields shall preserve the units defined for that field in the Profile.xlsx document. Scaling and offset defined in Profile.xlsx for the native data fields shall not be applied to the developer data field. Instead, the developer data field shall be logged with full precision and resolution using the appropriate base data type.
For example, if overriding total_hemoglobin_conc in the record message, which has a scaling of 100, the developer data field should be logged as a float (to keep two decimal places of precision).
Developer fields will be written to the FIT file in such a way that decoders do not need to manipulate them in any way. Decoders that are consuming developer data should not trust that developer data is logged correctly. It is still strongly recommended to do some basic data verification before attempting to display it.