Hi Peter,
As part of the FITSDK there is a FitCSVTool.jar provided. It is able to decode FIT files and output csv files. The relevant messages are: ant_channel_id, ant_tx, and ant_rx.
Usage:
java -jar FitCSVTool.jar "other options here"
There is also a Fit2CSV.bat file that you can drag a FIT file onto and it will create a csv file in the same place as the FIT file.
-Evan