the BE9558 / BE18003 extension-byte case
The bytes at [7]/[11]/[15]/[19] are an annotation field (purpose still
unclear — empirically non-zero on intervals with sub-Hz or unmeasurable
freq), NOT the high byte of the peak count. The N844 fixture corpus
the original RE was done against had zero values in those bytes for
every block, so uint8 and uint16 LE were equivalent there — but on
real BE9558 Tran-drift events and BE18003 Histogram+Continuous events
the uint16 LE interpretation produced peaks up to 268 in/s and 35×
inflated PVS sums.
Cross-correlated against BW's per-interval ASCII export on:
- K558LKZU/LL1P/LL3K → 100% T/V/L/M peak match (1435 blocks each)
- T003LKZR/LL0O/LL1M → 100% T/V/L, 99.3% M (0.05 dB rounding only)
- N599LKZS/LL0L → 100% all channels
- N844 fixture corpus → 100% all channels (unchanged)
Annotations preserved on every record for future RE; the defensive
_MAX_PEAK_COUNT bound is no longer needed (uint8 maxes at 1.275 in/s,
well below any physical limit).
Synthetic regression test added using the verbatim K558LKZU.RE0H
interval-12 block.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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