Simulink Modelling: Parameter estimation

I have created a model for parameter estimation.I have 3 constants in the model which I need to estimate but whenever I open Control and estimation toolbox for the estimation process no parameter appears in the ADD Parameter dialogue box. What should I do? Please help. Its urgent.

Answer 1

[Arkadiy Turevskiy]

Are the constants parameterized with variables that are present in MATLAB workspace?

From the doc: "The dialog box lists all the variables in the model workspace and the MATLAB® workspace that the model uses".

[Pratibha]

Thanks for helping. My problem is solved now.