Hi,
I have a Concept 2 model D with PM4 that can connect to the Garmin ANT+ devices.
The PM4 transmits the start/stop/power/cadence/speed data to the Garmin watch which records it.
The problem is that the Garmin connect site doesn't display the cadence chart. I know there were issues with the cadence chart when running with a foot pod, but these seemed to be fixed at least for me.
Here is a rowing session in which the cadence is not shown:
http://connect.garmin.com/activity/481079596
Later edit: I just noticed that the cadence data is not saved in the tcx file ... I was not expecting this. I will have to contact Concept 2.
Please support.