RNS 510 & DAB Radio

[VRS73]

Hi All

How do I find / select the DAB stations on an RNS 510?
I only seem to be able to select FM or AM.
The manual does not appear to help.
Its a 62 plate Alltrack.
I have looked in my father in laws SE and there they are, just press the radio button to select DAB.

Thanks for your help

Darren