Review r0 of Integration-W3:
- I1: the effective FC16 cap is min(configured maxRegistersPerWrite, 123). The
driver trusts a larger configured cap and sends an over-ceiling FC16 (past 127
registers its byte-count byte wraps), which every conformant device refuses, so
such an array is never advertised writable.
- I2: a BitInRegister[] write reads its span first in one unchunked FC03, so it is
also bounded by min(configured maxRegistersPerRead, 125) (absent/0 = 125).
- m2: every span (registers and coils) must end at or before address 65535.
- m1: the String-node wording says it converts only when the text parses, which
the server cannot promise (DateTime never converts).
- m4: the parity device now enforces FC01/02 2000, FC03/04 125 (or a smaller
device read limit), FC15 1968, FC16 123, FC23 121/125, the FC15/FC16 byte-count
field (exception 03) and the address-space end (exception 02).
Tests: parity rows for each ceiling/cap/span boundary against the real write
path, and Core.Abstractions row tests. The configured-cap test that asserted a
cap of 200 lifts the ceiling now asserts the opposite.
Refs #741
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
The Modbus lane (#741 U3) gave the driver String[] and BitInRegister[] holding-register array encoders, and
moved address resolution to ModbusTagAddressResolution (keys first, a bit region coerced to Bool, strict key
reads), but DriverArrayWriteSupport still listed both array shapes read-only (follow-up F1), so a client
write was BadNotWritable before it reached the driver.
Modbus row now mirrors the driver end to end:
- Keys shape only (region + address both present). A string-only addressString tag is resolved by the
driver with its own family through a parser Core.Abstractions cannot reference, so it stays read-only
(pinned: the conservative direction).
- Strict reads as the resolver: address an integer 0-65535; a present region / dataType / byteOrder /
stringByteOrder string must name a member.
- Coils: any dataType (coerced to Bool), <= 1968 coils (FC15).
- HoldingRegisters (FC16, never Bool): numeric, String ((stringLength+1)/2 registers, stringLength >= 1),
BitInRegister (1 register, bitIndex 0-15, span ending <= 65535), all within maxRegistersPerWrite.
FC23 is opt-in and never changes the answer.
- Elements convert (ScadaBridge int[] -> Int16 stays writable); only a String / DateTime node over a
numeric or bit element is left out, since such an element never converts.
Tests: the parity test's PendingF1 exemption and its guard are gone; the parity matrix is now region x
element type x node type against the real WriteAsync with a spec-conformant device (FC15 > 1968 refused),
plus shape edges at every cap boundary (numeric, String, BitInRegister, coil), strict key reads, FC23
on/off, string-only, the ScadaBridge int[] shape and U3 wire bytes. Core.Abstractions row tests and a
composer test (String[] and BitInRegister[] writable; over-cap, no-stringLength and string-only read-only).
Docs: table XML doc, Uns.md, modbus-addressing.md, drivers/Modbus.md, data-plane rules.
Refs #741
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
The Wave-2 lanes gave AbCip, AbLegacy and TwinCAT real whole-array write
encoders (review 07 U10/U9), but the capability table still listed all three
as scalar-only, so every array node materialised read-only and a client write
was BadNotWritable before it reached the driver.
Rows added, each listing only what WriteAsync encodes end to end:
- AbCip: SInt/USInt/Int/UInt/DInt/UDInt/Real/Dt/LInt/ULInt/LReal, declared
length, not a safetyTag. BOOL/STRING/Structure arrays stay read-only.
- AbLegacy: Int/AnalogInt on N/B/A, Long on L, Float on F (file-width match),
plain <file><n>:<word> address, <= 256 elements; not /bit, .sub, indirect,
S:/I:/O:, nor native PLC-5.
- TwinCAT: every codec element type, declared length; not a BOOL bit-in-word
path.
Elements convert in all three encoders, so the rows never key on an exact
node DataType (ScadaBridge int[] -> Int16 stays writable); they leave out
only node types whose elements never convert (DateTime/String over numeric,
Boolean on AbLegacy, STRING under DateTime on TwinCAT: culture-dependent).
Tests: driver-level parity for each driver (every element type x node type
plus shape cases, against the real write path), the AbLegacy parity tests
un-skipped, Core.Abstractions row tests, a composer test (three drivers
writable, refused shapes read-only), and the existing AbCip negative cases
moved to a BOOL array. Docs: Uns.md table, per-driver docs, data-plane rules.
Refs #737#738#739
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Keeps the root CLAUDE.md lean by lazy-loading per-area detail (drivers, topology,
data-plane auth, alarms, historian) only when matching files are touched.
Joseph Doherty