One more question, I found this:


Rotation speed output pin (open-drain)
This output is held low at startup and when an abnormality is detected. In sensorless mode,
pulses are generated at 3 ppr according to the back-EMF.
Note: 3 ppr = 3 pulses per electrical degree (With a four-pole motor, six pulses are generated
per revolution.)

The DDC is a 6 pole motor.

Electrical degrees is something completely new to me, but it appears that Hz x 10= RPM...is that right?