Review r0 I1. On the default libplctag transport a PLC refusal (non-zero PCCC
STS, e.g. an element past the end of the file; or a CIP error) arrives as
ERR_REMOTE_ERR / ERR_BAD_STATUS, which fell into the BadConnection default: a
no-reply comms fault. A coalesced block with one such member then failed as a
group every poll, and two refused tags in a row opened the device's fail-fast
window against a device that was answering.
- LibplctagLegacyStatusTranslation maps ERR_REMOTE_ERR / ERR_BAD_STATUS to the
existing AbStatus.DeviceStateConflict (BadDeviceFailure): "reachable, refused
the operation". No new AbStatus value (Driver.Ab.Transport is Lane K's).
- IsNoReply (Timeout / BadConnection / Abort / Pending / unknown codes) is now
the ONLY comms-fault class; IsDeviceRefusal is every other non-Ok status
except Unsupported (BadReply / Partial included: a reply arrived).
- A coalesced block refused with ANY returned status falls back to per-member
reads in the same pass; the shape is remembered only after a repeat, and the
refused block's handle is always evicted (M5).
- A runtime status Unsupported is neutral (keeps the handle); the probe no
longer counts it as a fault.
- Refusal warnings log the status actually answered (M8).
Live: the new past-end-of-file ab_server case fails on libplctag with the old
translation and passes with it, on slc500/micrologix/plc5 x both transports.
Refs #738
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Joseph Doherty
8a80dcc787