How do i get a record in the tlc file?

I try to generate Code from a Simulink model. One Kind of Signal is declared as Constant and when i write a Parameter in this block i get a record and i am able to generate my code. The other Kind of signals are declared as Input and i didn't get any records of that and am not able to get any data in my Code. Does someone has a clue how to get a record for this?