SATp1 no transmission for specific bands

[jlashner]

Sometimes on SATp1 we've seen that certain individual bands have no transmission. Because this is an individual band and not full AMC, I think we can rule out connection / cryo error.

This results in transmission plots that look like this:

that end up causing all sorts of errors for various sodetlib operation issues.

Sometimes this can be fixed by hammering the slot. Most recently, I've found this behavior on Mv22: (more is documented in this notes page)

At first bands 3 and 5 were showing no transmission. After hammer, bands 3 and 5 were both fixed, but band 0 was showing no transmission. @swh76 do you have any idea what might be causing this?

[jlashner]

Just some more detail, after tuning finished I tried to take full-band response to see if that looked the same. Full band response for band 0 actually looks good:

while the full-band amplitude sweep looks awful:

This could be a clue.

[swh76]

@jlashner this one's new to me.
First thoughts;

• The full_band_resp vs full_band_ampl_sweep is interesting. The former just plays a waveform on the DAC and receives on the ADC for that band ; so it bypasses the DSP. full_band_ampl_sweep, like find_freqs, generates and receives tones via the DSP (e.g. via the analysis/synthesis PFBs). So may be pointing to a misconfiguration of the DSP.
• Can you get now or next time this happens, the following?
  -- State dump. I usually do this; import time; S.save_state(f'/data/smurf_data/{int(time.time())}_slot{S.slot_number}_state.yml'). FYI it takes 30 sec or so before the file finishes getting written to disk.
  -- Rogue (you call this streamer) logs ; here looking for any missed reg sets. E.g. if for some reason you're dropping an occasional register write, could imagine you're missing a critical DSP configuration register.
  -- Does issue resolve w/ second setup?

And a question ; does a band ever "go bad" e.g. full_band_ampl_sweep looks fine but stops working later? Or as far as we know if it's good after initial hammer, does it stay good?