ApplyScaling (HistorianTagDefinition.ApplyScaling):
The EnsT2 trailer's second byte controls server-side scaling — `FE 00`
mirrors MinRaw to MinEU and sets AnalogTag.Scaling=0; `FE 01` persists
distinct MinRaw/MaxRaw and sets Scaling=1. Decoded by toggling
set_ApplyScaling on the native harness and capturing the wire bytes for
both values with identical inputs. The earlier docs claimed
EnsureTagAsync needed a follow-up "UpdateTags" call; the WCF surface has
no such operation — toggling that one byte is the whole fix.
StorageRate (HistorianTagDefinition.StorageRateMs):
Serializer accepts a non-default rate, validated empirically against
the live server which only accepts quantized values
(1000/5000/10000/60000/300000 ms).
EnsureTagAsync upsert semantics:
Second call on the same tag name with different fields succeeds and
updates Description, MinEU, MaxEU, MinRaw, MaxRaw, Scaling in place
(verified by direct SQL inspection in a live test).
Plan + doc closeout:
write-commands-reverse-engineering.md rewritten as a current-state
plan with three workstreams (A doc closeout / B idempotency / C1
StorageRate) and a parallelism table; prior phase notes preserved as
appendix. handoff.md, implementation-status.md, wcf-contract-evidence.md,
README.md updated to remove "writes are out of scope" / non-existent
UpdateTags references and document the actual EnsT2 wire format
including the `FE xx` trailer.
Reverse-engineering harness gains --write-apply-scaling and a SQL
post-check that prints the persisted AnalogTag bounds so future RE
sessions can verify wire→DB causality without leaving the harness.
169/169 tests pass (was 165; +4 new tests covering ApplyScaling,
StorageRate golden bytes, StorageRate live persistence, and
EnsureTagAsync upsert semantics).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Executes docs/plans/tcp-connection-validation.md. Full read-only SDK
surface now works against a remote AVEVA Historian over Net.TCP with
Windows transport authentication. 124/124 tests pass; the +10 new live
integration tests in RemoteTcpIntegrationTests.cs are gated by
HISTORIAN_REMOTE_TCP_HOST + HISTORIAN_REMOTE_TCP_TAG.
Two SDK bugs found while executing the plan:
1. Historian2020ProtocolDialect.ReadRawAsync / ReadAggregateAsync /
ReadAtTimeAsync / ReadEventsAsync had explicit
`if (_options.Transport != HistorianTransport.LocalPipe) return Missing<T>`
guards. These were a guardrail from before the orchestrators handled
TCP; the orchestrators have always used CreateBindingPair(options)
which dispatches on transport correctly. Gates removed.
2. HistorianWcfStatusClient and HistorianWcfEventOrchestrator hardcoded
HistorianWcfBindingFactory.CreatePipeEndpointAddress for the auxiliary
services (Stat, Trx, Retr). Worked for LocalPipe; for TCP it produced
an EndpointAddress with scheme net.pipe attached to a TCP binding
(channel factory rejected the URI). Worse, when only the endpoint was
transport-aware, the binding still requested a Windows-transport-
security upgrade that the Stat endpoint over TCP doesn't support
(auxiliaries don't repeat the auth — the Hist session is already
authenticated). Added two helpers:
- HistorianWcfBindingFactory.CreateAuxiliaryEndpointAddress(options, name)
-> net.pipe for LocalPipe, net.tcp for remote
- HistorianWcfBindingFactory.CreateAuxiliaryBinding(options)
-> NamedPipe for LocalPipe, plain MdasNetTcpBinding for remote
Both call sites updated.
Live verification against the remote (probed previously in prior
sessions; reachability re-confirmed today):
- ProbeAsync over RemoteTcpIntegrated and RemoteTcpCertificate
- ReadRawAsync (8 samples returned for SysTimeSec)
- ReadAggregateAsync (TimeWeightedAverage, 1-min cycle, 10-min window)
- ReadAtTimeAsync (3 timestamps)
- BrowseTagNamesAsync (finds the test tag)
- GetTagMetadataAsync (full metadata populated)
- ReadEventsAsync (chain runs without throwing)
- GetConnectionStatusAsync (ConnectedToServer=true)
- GetSystemParameterAsync (HistorianVersion="20,0,000,000")
The default 'NT SERVICE\aahClientAccessPoint' SPN turned out to work
for the remote too — discovery workstream A (SPN-finding) was not
needed in practice.
README and the TCP plan doc updated to reflect the executed status.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty