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I have successfully built Simulation example: FSK. Everything works fine and I'm getting same results as in example.
For the next step I would like to save demodulated binary data in file but I'm getting way too many samples per bit (maybe because of repeat block used in beginning of simulation?). How do I decimate such a large amount of samples? When using rational resampler (between Frequency Xlating FIR Filter and Quadrature demod) with decimation 1056 I get

sched: <block rational_resampler_base<IN_T,OUT_T,TAP_T> (1)> is requesting more input data than we can provide. ninput_items_required = 36778 max_possible_items_available = 8191 If this is a filter, consider reducing the number of taps.

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Okay, I figured it out myself. I will share my solution. After some googling I realized that this is clock recovery problem, so I used Clock Recovery MM block (with default parameters except for Omega). From Clock Recovery MM

If the input signal pulses do not have peaks (e.g. rectangular pulses) the input signal should be conditioned with a matched pulse filter or other appropriate filter to peak the input pulses. For a rectangular base pulse that is N samples wide, the matched filter taps would be [1.0/float(N)]*N

As rectangular pulses is my case I added Decimating fir filter with taps np.ones(int(samp_rate/baud)-1)/int(samp_rate/baud) and decimation 1056/4 = 264 and for Clock Recovery MM (which is decimation block) I put Omega = 4. enter image description here

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