A. #566 on a real CompactLogix (Z-35162, read-only): a class-3 connection idled 60 s past its
16 s timeout is closed at the TCP level, not with CIP 0x0107/0x0203; the next request fails on
its write (Broken pipe -> BadConnection) in 9 ms and the one after reopens. The transport already
handles this, so no production behaviour changed; the shape is pinned offline by
CipConnectionTests.A_target_that_resets_an_idle_session_... (FakeEipServer.ResetAllConnections),
proven red with a reconnect-skipping mutation. The diagnostics-only exchange tap now also sees
Forward Open replies (granted RPIs).
B. Native STRING write through the driver on Program:ES03_TemperatureControl._StrTmp: write,
read back, restored byte-exact (user-approved). Array write NOT run: the census's unreferenced
DINT[32] _SEQ_EP arrays are aliased sequencer step registers (raw L5X grep), so none qualifies.
#567 still impossible (a 128 B array / 88 B STRING never fragments).
New env-gated harness: AbCip.IntegrationTests/HardwareGate (IdleConnectionEvidenceTests,
StringWriteGateTests). Docs: gate results (hw5 section + raw output), AbCip.md, CLAUDE.md.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Pass 2 (2026-10-08 00:21Z, df776170): 17/17. Browse 3162=3162 tags, 20 UDT
templates identical, 200 tags read with 0 unexpected divergences (6 live
values compared structurally + every still element), 1 Forward Open and 1
acked Forward Close per native phase. Latency native p95 105.8 ms vs
libplctag 139.5 ms (limit 153.4) PASS. Pass 1 failures and their fixes are
recorded in the gate-results doc; pass 2 had no independent pcap.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Joseph Doherty