@Jommag and I discovered something interesting.
Seems to Simulator printing "OK" when sending CrankRotation event to the device.
Demonstration: https://youtu.be/CpvRUTEd7gg
CC @dave
I suppose it also can be answer by OS's repr to received command, but I can't reproduce it right now. If so it's OK, but anyway it makes dev-logs in Sim's console kinda mess.