Full needle rib is created by using both needle beds of a flat-bed knitting machine. It consists of wales of front and rear stitches lying next to each other. In relaxed position you only see the front stitches on both sides of the fabric. Only when it is stretched horizontally the rear stitches are visible. Full needle rib is very elastic.
To create a full needle rib structure in the software, go to Free edit and pick a drawing tool.
Then open the stitch palette on the left, and select "Knit both".
Make sure you use a 0.5 rack to prevent the needles from interfering with each other.
Below a detail of the double jersey structure.
Here are the recommended parameters for a full needle rib (nm7):
Stitch size: 3-4