Range of accepted values in parametric inputs?

[yowzadave]

Hi:

Is it possible to create an instance parameter that is restricted to a specified range (say, from 0 to 25 feet)? So that if the family is instantiated, and the user changes that parameter to some invalid value (like -100 feet) then it will be reset to 0 feet?

I'm assuming that this would be done using a conditional statement, but I keep getting the error "circular chain of reference" whenever I try to make this happen.

Thanks!

[Alfredo Medina]

The circular reference error occurs because probably you are including in your conditional statement the same parameter used for user input. You need another parameter with this formula to avoid the error.



IF (Length < L Min, L Min, IF (Length > L Max, L Max, Length))


See illustration.

[Scott Womack]

Here is a blog that effectively addresses that issue.
http://revit-nightmares.blogspot.com/