ADuM4136 VDESAT Reference

Hi, in our application we're using ADuM4136 with MOSFETs and I was wondering what the Vdesat 9V source is referenced to internally. The functional diagram in rev 0 of the datasheet references the internal clamp and the 9V source to VSS2. However, since the purpose is to measure across the Vds of the device, and the source is connected to GND2, the reference should be to GND2. Also, when I monitor DESAT with respect to GND2, the voltage is clamped at 0V (GND2), not VSS2. Also, the eval boards tie the Cblank caps to GND2, not VSS2, which implies the proper reference internally is also GND2. Can you please confirm which reference is correct?

Thank you!

Ben @ Stealth Space Company