The channel block is only present in the full ~2126-byte cfg (when frame D
delivers correctly rather than duplicating frame B's page). Layout per §7.6:
[00 00][max_range f32][00 00][trigger f32]["in.\0"][alarm f32]["/s\0\0"][00 01][label]
Relative offsets from the "Tran" label position (label-24/label-18/label-10)
are validated by checking the unit strings "in.\0" at label-14 and "/s\0\0"
at label-6 before reading the floats. Guard against "Tran2" false-match.
When frame D duplicates, cfg is ~1071 bytes and tran_pos search returns a hit
without the unit string sentinels — we log the miss and leave fields None.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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