Couldn't find any hint in the docs.
I connect the HR+ to the PC via BT.
Then starting GC and trying to connect the sensor via Tools/Options/Train... Strat the Assistent by hitting "+" , choose BT 4.0, proceed to virtual power window which I ignore, and in last window I enter a name and finish.
Now in Train I can start the workout. But HR count remains at 0.
The sensor does work when connected to the Movesense mobile APP. I'm aware that it can only be connected either to the phone or to the PC. So I'm always disconnecting when changing devices.
I will need to study the Movesense API docs to find a different way of checking the HR+ via PC.