Hi testpoint,
DANL is specified at 0 attenuation and max gain (maximum receiver sensitivity). If you set your reference level to -50 the BB60C will be configured for maximum sensitivity and you will see the DANL you expect.
The way our software currently works, is that the sensitivity (atten/gain) is configured automatically from the reference level. You can control the gain/atten manually in the control panel, you will need to disable the lock on those controls in the file->settings menu (or F11).
Let us know if you have additional questions.
Regards,
Andrew