I am looking for short burst signals. Specifically, the duration of the signals are almost 25 ms and are repeated every some seconds (1 to 4). The signals are relative strong with BW of almost 50 KHz. I study the documentation of the DAQ firmware and I saw that I can enable the en_squelch mode but I can not find the appropriate .ini file for doing that. Where I can do that? Is Optimize Short Bursts setting of the web config exactly the same? Also, should I decrease the block size too? Or given that the default is already smaller than the inter-arrival time I am ok?
You might be looking at the old documentation of the DAQ. Most of that is still the same, but the DAQ squelching system has been removed in favor of squelching on the DSP side.
Originally squelching was implemented on the DAQ side in the time domain, but it was terribly unreliable and would often miss weak signals. So it was implemented on the DSP side in the frequency domain where it was significantly more reliable.
Optimize short bursts changes the FFT window to something that better handles short bursts, and hence improves the squelch detection.
1 Like