Several people in Polar forums reported issues with CS600 logs not showing any HR and RR data. It seems that there is a bug either in the transmission from the watch or in PPT5. I discovered that you will not any HR if you start the HRM before the HR shows on the CS600 display. Member BorutV confirmed that the logs staring with few zeroes are not displaying any HR in PPT5. In any case there is a workaround. Just follow these simple steps and you should get the log with HR and RR data without any issues:
Wear the HR belt
Press the red button once
Wait for the HRM to find and connect with the belt - basically until the HR appears on the display
Now you can press the red button again to start the exercise