max_freq crfa_max_freq [crfa] import crfa crfa.max_freq($fft_len, $num_decoders, $center_freq, $samp_rate) set_center_freq($center_freq); fft_len fft_len int num_decoders num_decoders int center_freq center_freq float samp_rate samp_rate int in float $fft_len out message 1