time dependant simulation: variable input

Hi everybody,

I am trying to simulate and validate an air solar collector model. I would introduce time-dependant (hourly time step) input for air temperature and solar radiation using an interpolation function but running the simulation some errors occur (see attached file).

I set the unit in the interpolation function branch: argument=s; function=K (e.g.) and use the name function wherever I need recall it as: name(t).

Could someone help me?

thanks in advance, Giuliana.