Do I have to turn on/off the device? You do not need. The device turns on and sleeps automatically. Tagged: power meterpowercranktwin2 Related Articles How to connect multiple devices with each other? – Zwift, Smart Trainer, Bicycle computers etc. How to install and start the device? Where can I find serial number and ANT+ ID? How to connect the POWERCRANK with my bike computer? How to perform calibration? How often do I need to perform calibration on my device?