How Do NEO Series Smart Trainers Measure Cadence?

NEO Series Smart trainers measure your cadence from the non-drive side crank arm of the bike without the help of a sensor. The trainer constantly measures your speed and uses this to determine your cadence. The speed is zero at the top of the pedal stroke and it is maximal in between. The trainer uses this information to know when you have made a full circle in order to define your cadence.