Change slope ratio of slab - why Parameter Read Only?

I am trying to create a simplified way to enter the slope ratio of a slab using Dynamo (ie. 1"/12"). I tried to get and set parameters, but got a “parameter is read only” error.

Since my slab has 2 curved sides, I could not use Revit to define the slope based on the edge of slab. The slope ratio should match the one shown at 1"/12".

I could do some math and use the Slope Arrow to draw the change in height. I’d rather be able to change the actual slope, which is grayed out under Dimensions.

I tried GetParameter and the value was empty, which is currently accurate. I then attempted to SetParameter and I received the error:

Why can’t I change a “Read Only” parameter? Is there a way to change the value of read only parameters? Is there a way for me to enter the slope as a ratio to the SetParameterByName node?

  • Thanks! :grin: