help using matlab/simulink with arduino mega 2560

Hello, I am trying to create / modify a Simulink block from Target use with Arduino , the PWM one which gives a Pwm signal with variable duty cycle.The only problem is I need a pwm frequency of 30khz ( prescaler set to 1 i think ) and i do not know how to modify the existent one or create a new one which does that.Any help appreciated.Thank you

Did you ever solve this problem? We are having the exact same question and are very stuck.