- S7TagDefinition gets optional ElementCount; >1 marks the tag as a 1-D array.
- ReadOneAsync / WriteOneAsync: one byte-range Read/WriteBytesAsync covering
N × elementBytes, sliced/packed client-side via the existing big-endian scalar
codecs and S7DateTimeCodec.
- DiscoverAsync surfaces IsArray=true and ArrayDim=ElementCount → ValueRank=1.
- Init-time validation (now ahead of TCP open) caps ElementCount at 8000 and
rejects unsupported element types: STRING/WSTRING/CHAR/WCHAR (variable-width)
and BOOL (packed-bit layout) — both follow-ups.
- Supported element types: Byte, Int16/UInt16, Int32/UInt32, Int64/UInt64,
Float32, Float64, Date, Time, TimeOfDay.
Closes#290
Adds S7DateTimeCodec static class implementing the six Siemens S7 date/time
wire formats:
- DTL (12 bytes): UInt16 BE year + month/day/dow/h/m/s + UInt32 BE nanos
- DATE_AND_TIME (8 bytes BCD): yy/mm/dd/hh/mm/ss + 3-digit BCD ms + dow
- S5TIME (16 bits): 2-bit timebase + 3-digit BCD count → TimeSpan
- TIME (Int32 ms BE, signed) → TimeSpan, allows negative durations
- TOD (UInt32 ms BE, 0..86399999) → TimeSpan since midnight
- DATE (UInt16 BE days since 1990-01-01) → DateTime
Mirrors the S7StringCodec pattern from PR-S7-A2 — codecs operate on raw byte
spans so each format can be locked with golden-byte unit tests without a
live PLC. New S7DataType members (Dtl, DateAndTime, S5Time, Time, TimeOfDay,
Date) are wired into S7Driver.ReadOneAsync/WriteOneAsync via byte-level
ReadBytesAsync/WriteBytesAsync calls — S7.Net's string-keyed Read/Write
overloads have no syntax for these widths.
Uninitialized PLC buffers (all-zero year+month for DTL/DT) reject as
InvalidDataException → BadOutOfRange to operators, rather than decoding as
year-0001 garbage.
S5TIME / TIME / TOD surface as Int32 ms (DriverDataType has no Duration);
DTL / DT / DATE surface as DriverDataType.DateTime.
Test coverage: 30 new golden-vector + round-trip + rejection tests,
including the all-zero buffer rejection paths and BCD-nibble validation.
Build clean, 115/115 S7 tests pass.
Closes#289
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Closes the NotSupportedException cliff for S7 string-shaped types.
- S7DataType gains WString, Char, WChar members alongside the existing
String entry.
- New S7StringCodec encodes/decodes the four wire formats:
STRING : 2-byte header (max-len + actual-len bytes) + N ASCII bytes
-> total 2 + max_len.
WSTRING : 4-byte header (max-len + actual-len UInt16 BE) + N×2
UTF-16BE bytes -> total 4 + 2 × max_len.
CHAR : 1 ASCII byte (rejects non-ASCII on encode).
WCHAR : 2 UTF-16BE bytes.
Header-bug clamp: actualLen > maxLen is silently clamped on read so
firmware quirks don't walk past the wire buffer; rejected on write
to avoid silent truncation.
- S7Driver.ReadOneAsync / WriteOneAsync issue ReadBytesAsync /
WriteBytesAsync against the parsed Area / DbNumber / ByteOffset and
honour S7TagDefinition.StringLength (default 254 = S7 STRING max).
- MapDataType returns DriverDataType.String for the three new enum
members so OPC UA discovery surfaces them as scalar strings.
Tests: 21 new cases on S7StringCodec covering golden-byte vectors,
encode/decode round-trips, the firmware-bug header-clamp, ASCII-only
guard on CHAR, and the StringLength default. 85/85 passing.
Closes#288
Per-tag opt-in for write-retry per docs/v2/plan.md decisions #44, #45, #143.
Default is false — writes never auto-retry unless the driver author has marked
the tag as safe to replay.
Core.Abstractions:
- DriverAttributeInfo gains `bool WriteIdempotent = false` at the end of the
positional record (back-compatible; every existing call site uses the default).
Driver.Modbus:
- ModbusTagDefinition gains `bool WriteIdempotent = false`. Safe candidates
documented in the param XML: holding-register set-points, configuration
registers. Unsafe: edge-triggered coils, counter-increment addresses.
- ModbusDriver.DiscoverAsync propagates t.WriteIdempotent into
DriverAttributeInfo.WriteIdempotent.
Driver.S7:
- S7TagDefinition gains `bool WriteIdempotent = false`. Safe candidates:
DB word/dword set-points, configuration DBs. Unsafe: M/Q bits that drive
edge-triggered program routines.
- S7Driver.DiscoverAsync propagates the flag.
Stream A.5 integration tests (FlakeyDriverIntegrationTests, 4 new) exercise
the invoker + flaky-driver contract the plan enumerates:
- Read with 5 transient failures succeeds on the 6th attempt (RetryCount=10).
- Non-idempotent write with RetryCount=5 configured still fails on the first
failure — no replay (decision #44 guard at the ExecuteWriteAsync surface).
- Idempotent write with 2 transient failures succeeds on the 3rd attempt.
- Two hosts on the same driver have independent breakers — dead-host trips
its breaker but live-host's first call still succeeds.
Propagation tests:
- ModbusDriverTests: SetPoint WriteIdempotent=true flows into
DriverAttributeInfo; PulseCoil default=false.
- S7DiscoveryAndSubscribeTests: same pattern for DBx SetPoint vs M-bit.
Full solution dotnet test: 947 passing (baseline 906, +41 net across Stream A
so far). Pre-existing Client.CLI Subscribe flake unchanged.
Stream A's remaining work (wiring CapabilityInvoker into DriverNodeManager's
OnReadValue / OnWriteValue / History / Subscribe dispatch paths) is the
server-side integration piece + needs DI wiring for the pipeline builder —
lands in the next PR on this branch.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
