Five records out of order at every SNUADC reset¶

At each step-mode reset the five records after it are written in the wrong order: two continue the old timing and three start the new, interleaved. Read in file order, or sorted by stamp, one second of signal is scrambled.


Status	established: shown on many cases, with a control.
Clocks	SNUADC sample clock
Devices	SNUADC, Vital Recorder
Variables	ECG lead II (SNUADC), Arterial pressure (SNUADC), Plethysmogram (SNUADC)

What it means¶

Any reader that keeps file order or sorts by stamp (the vitaldb package included) scrambles about 1 s of every SNUADC channel at each reset, roughly every two hours of step-mode recording.

What is done about it¶

The TimeNet import puts the records back in sampling order by default (VITALDB_RESET_ORDER), and the clock fits use the same order; a fit and a build in different orders are not combined.

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.
Clock corrections in every file	2026-10-11	current	A scan of all 6,388 files for the jumps where the recorder re-synchronises a device's stamps. Each device type has its own correction signature; only SNUADC and BIS correct clearly enough to measure their drift.