In 34 files the SNUADC records overlap throughout¶
In 34 files the SNUADC records step back over their neighbours far more often than resets explain: in 20 of them 4–95% of all record junctions overlap, by up to about 100 ms. The reset-order rule matches there by coincidence.
| Status | open: seen, not explained. |
| Devices | SNUADC, Vital Recorder |
What it means¶
Read in file order, these files hold overlapping samples; reordered by the reset rule, they would be scrambled. Their timing should not be trusted until the cause is known.
What is done about it¶
The record-level signal survey (19 October) explains the worst of them: records written twice (Eight recordings store whole messages twice, 8 recordings) and two interleaved streams (In some recordings two unrelated streams are interleaved in one track, 12 recordings), which also affect Primus and BIS. Drop the duplicates; treat interleaved tracks as unusable. The reset-order rule still needs a guard that skips such tracks before the next full build. None is in the current builds or clock fits.
Evidence¶
| Study | Date | Status | Summary |
|---|---|---|---|
| Records out of order at SNUADC resets, and where the lost time goes | 2026-10-17 | current | At every SNUADC reset the five records after it are written out of order: two continue the old timing and three start the new. Put back in order, the waveform runs on with no samples missing; the 18–20 ms lost at each reset goes missing inside the last old-timing record, and an extra zero sample follows. |