Fsk modulation


I am new to gnu radio and i need to make fsk modulation using grc. i
fould some fsk codes but they are for old usrp(usrp1) and we use usrp
n210 in laboratory. i am trying to make fsk for months but i dont know
much about telecom i just know little c++. how can i find a source to
learn this or fsk.grc file?

Thank you very much for your help.
Best regards