- ReadBucketAsync: the once-per-device "sum-read chunk failed" Warning fires only after a successful
connect; a connect/backoff failure is the connect path's to report. TwinCATSumChunkWarningTests pins
it (no warning across connect failures, exactly one across two later failing sum polls; red without
the guard) plus a source guard that ReadGroupAsync builds its SumRead only via CreateSumRead.
- Docs: diagnostics live-gated via the driver harness (/hosts not exercised); TC2 costs 8 reads on the
first tick and after each reconnect, then <= 4; read counts attributed to the unit tests.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe