So after two straight days of figuring out how to build my form that contains water meter points with a related table of meter readings, I have almost completed the form the way I want.
However, I don't understand how to order my existing repeats by descending from my date field.
This is what I have so far (which works):

However, if I try to add (with a space), orderBy=${ReadingDate} after query-'1=1', the form fails to download the repeats.
Can someone please help me with what I need to put in? In the form, I would like the repeats to show the latest to oldest records, as you tap the forward arrow button.
Thank you,