The drive sends the PVT status to the host when:

– the PVT buffer is full, low or empty;
– some PVT points are “missing” – for example, in case the host sends 4 points but the 3rd point was not received by the drive.

Remark: In case of buffer empty condition, the drive enter QUICKSTOP mode if the velocity of the last PVT points was different from zero.