I have to draw something in Solid edge in 2D, with the scale 1:2. I don't know how to fix the measure. For example 150mm which is already converted by 1:2 from the original 300mm, so that I can write 300mm and the draft don't change.
You need to draw in 1:1 scale in the 2D Model page, then in Sheet 1 you can create views in 1:2 scale and the dimensions will still be correct.
2D model \ Sheets it is like the Model space \ Paper space in AutoCad