how to make a frequency variable voltage supply for sweeping frequencies in simulink

There is a RLC low-pass filter that i want to simulink it in MATLAB. i need to apply a voltage supply to it's input with changing frequency. there is a block in name of 'chirp signal' but i have no information about using that. pleas help me to make this voltage supply in simulink of MATLAB with changing frequency specific.

[mohammad]

no idea? please help