I1: the U11 Bits[n] -> Bits[n/32] rewrite was unconditional. The native
runtime now keeps the original element path until the first reply settles the
layout: 0xD3 confirms DWORD addressing (bit n%32); any other reply type (e.g.
a 0xC1 per-element BOOL array) or a refusal of the DWORD index falls back to
Bits[n] and re-reads, and a write settles the layout by a read first, so it can
never decode or write element n/32 of an element-addressed array.
I2: libplctag ErrorNoMatch/ErrorBadDevice no longer fold into NotFound (they
now read as BadConnection: comms, Degraded, LastSuccessfulRead preserved).
ErrorNotImplemented - and the native runtime's own pre-send refusals - raise
AbCipLocalRefusalException: BadNotSupported, no health, LastSuccessfulRead NOT
advanced, no backoff record, not reachable for the probe or Test Connect.
M1: the bit RMW's parent read/write status words follow the health contract
(refusal: per-tag Bad + Warning; comms: evict the parent + Degraded).
M2: device Unsupported read refusals return Refused (advance
LastSuccessfulRead); device write refusals call RecordWriteAnswered (not the
pre-send native type gate).
M3: a good write clears a Degraded a write comms fault recorded (a read-side
Degraded is still left for the read path).
M4: a superseded init throws AbCipInitializationSupersededException (not an
OCE); ShutdownAsync stamps Unknown only if no newer init published meanwhile.
M5: the sync-Dispose timing assert is 2 s against a 4 s probe read; the
unencodable-array test asserts health.
Refs #737
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
H17: the .n read-modify-write hard-coded a DINT parent. On an INT or SINT host
(both legal in Logix, and reads of Flags.3 there already worked) the DINT
decode of a 2-byte buffer threw OutOfBounds, the generic catch evicted the BIT
tag's (non-existent) runtime and reported BadCommunicationError + Degraded.
The parent width now comes from the parent read's size (1 SINT / 2 INT /
4 DINT / 8 LINT; unknown keeps the DINT assumption). Narrow hosts use unsigned
arithmetic so a set top bit encodes without overflow; a bit past the host's
width is BadOutOfRange and a non-integer width BadTypeMismatch, both refused
before anything is written, warned once, no health write. A transport failure
in the RMW now evicts the parent runtime it actually used. Native end-to-end:
an INT host is written as ONE INT (type 0xC3, 2 bytes).
Refs #737
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Joseph Doherty