can i cosider a state space model for manipulatede variable in mpc?

im using mpc for my system which has 2 input,one disturbance and one manipulated variable.i need to consider a model for manipulated variable,is it possible or not?

when i consider a state spsce model to manipulated variable i give this error

Incorrect number of parameters supplied for 'MPC:utility:InvalidModelField'. Expected 1 but found 0. i need help this is urgent

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/29922-why-your-question-is-not-urgent-or-an-emergency