axlDBGetPad(viaID "TOP" "REGULAR")->radius always returns 0 despite the actual pad diameter

Hello, 

I'm trying to read the PAD radius by:

axlDBGetPad(viaID "TOP" "REGULAR")->radius always returns 0 despite the actual pad diameter

and I always get 0.0 despite in padstack editor, all layers pad diameters are set to a positive value. 

Is there a correct way to get pad radius of Via?

Thanks